max12900 ultra-low-power 4-20a sensor transitter package: 5mm x 5mm x 0.8mm 32-pin tqfn applications...
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General DescriptionThe MAX12900 is an ultra-low-power, highly integrated 4-20mA sensor transmitter. The MAX12900 integrates ten building blocks in a small package: a wide input supply voltage LDO, two conditioner circuits for pulse-width-modulated (PWM) inputs, two low-power, low-drift, general-purpose operational amplifiers (op amp) one wide bandwidth, zero-offset drift operational amplifier; two diagnostic comparators, a power-up sequencer with power good output to allow for a smooth power-up, and a low-drift voltage reference.The MAX12900 converts PWM data from a microcontroller into current over a 4-20mA loop with two, three, or four-wire configurations.The equivalent to an ultra-low-power, high-resolution, digital-to-analog converter is realized with the combination of two-PWM signals received from a microcontroller, the two conditioner circuits, and an active filter built with the integrated low-power op amp. The outputs of the two conditioner circuits provide a stable PWM amplitude over voltage supply and temperature variation. The wide band-width amplifier, in combination with a discrete transistor, converts a voltage input into a current output and allows HART and Foundation Fieldbus H1 signal modulation. The zero-offset operational amplifier and the low-drift voltage reference provide negligible error over wide temperature. The low-power operational amplifier and comparators provide building blocks for enhanced diagnostic features. Supply rail monitoring, output current readback, open circuit and failure detection are a few examples of diagnostic features. All these features, as well as ultra-low-power and high accuracy make the MAX12900 ideal for loop-powered smart sensor transmitters for industrial application.The MAX12900 is available in 5mm x 5mm 32-pin TQFN package and operates over a wide industrial temperature range of -40°C to +125°C.
Benefits and Features Wide Input Supply Range: 4.0V to 36V Ultra-Low-Power Consumption: 170µA (typ) High Linearity: 0.01% (Max Error) High Resolution: Up to 16 Bit Low Drift Voltage Reference: 10ppm/°C max Wide Temperature Range: -40°C to +125°C Small Package: 5mm x 5mm x 0.8mm 32-pin TQFN
Applications Loop-Powered 4-20mA Current Transmitter Smart Sensors Remote Instrumentation Industrial Automation and Process Control
Ordering Information appears at end of data sheet.
19-100086; Rev 2; 3/18
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
EVALUATION KIT AVAILABLE
MAX12900
POWER-UP SEQUENCER
VCCID PWRGOOD
REFGND
VCCILDOFB
1.2V VREF
VCC
COMP2NCOMP2O
COMP2P
COMP1N
COMP1PCOMP1O
VCCI VDD
LDO
OP3
PWMBOPWMBP
VCCI REFBUF1V
PWMAO
PWMAP
VCCI1V
SHDN
SHDN
2.5V VREF
VCCI
VCCI VDD
VCCI VDD
VCCI
REFO
REFBUF
OP1OP1P
OP1NOP1O
VCCI
OP3P
OP3NOP3O
VCCI
OP2
VCCI
OP2P
OP2NOP2O
EP
COMPARATORS
OP-AMPS
PWM
VREF
MAX12900 INTEGRATES 10 BUILDING BLOCKS:LDOPOWER-UP SEQUENCERTWO COMPARATORS (COMP1, COMP2)TWO GENERAL PURPOSE OP AMPS (OP1, OP2)ONE LOW DRIFT OP AMP (OP3)2.5V PRECISION REFERENCETWO PWM RECEIVERS (PWMA, PWMB)
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Functional Block Diagram
VCC to GND ..........................................................-0.3V to +40VVCC to VCCI .........................................................-0.3V to +40VVCCI and VCCID to GND .......................................-0.3V to +6VVCCI to VCCID .....................................................-0.3V to +0.3VVDD to GND ............................................................-0.3V to +6VPWRGOOD to GND .................................. -0.3V to VCCI + 0.3VLDOFB to GND ......................................... -0.3V to VCCI + 0.3VI/C and REFGND to GND ...................................-0.3V to + 0.3VSHDN to GND ........................................... -0.3V to VCCI + 0.3VREFO to GND ........................................... -0.3V to VCCI + 0.3V
Op AmpsOP1O, OP2O, OP3O to GND ................... -0.3V to VCCI + 0.3VOP1P, OP1N, OP2P, OP2N, OP3P,
OP3N to GND ......................-0.3V to min [4.5V, VCCI + 0.3V]Current into OP1P, OP1N, OP2P, OP2N,
OP3P, OP3N .................................................................±20mACurrent into OP3O............................................................±30mAOutput Short-Circuit Duration for OP1 and
OP2 to VCCI or GND ............................................Continuous
ComparatorsCOMP1P, COMP1N, COMP2P, COMP2N
to GND ................................................... -0.3V to VCCI + 0.3VCOMP1O, COMP2O to GND ..................... -0.3V to VDD + 0.3VCurrent into COMP1P, COMP1N,
COMP2P, COMP2N .....................................................±20mAOutput Short-Circuit Duration to
VDD or GND ..........................................................ContinuousPWM ConditionersPWMAP, PWMBP to GND ......................... -0.3V to VCCI + 0.3VPWMAO, PWMBO to GND ....................... -0.3V to VCCI + 0.3VCurrent into PWMAP, PWMBP .........................................±20mAOutput Short-Circuit Duration to VCCI or GND .........Continuous
Continuous Power Dissipation (TA = +70°C, derate 35.7mW/°C above +70°C) ...........................2857.1mW
Operating Temperature Range ......................... -40°C to +125°CFunctional Temperature Range
(Startup condition) ........................................ -55°C to +125°CMaximum Junction Temperature .....................................+150°CStorage Temperature Range ............................ -65°C to +150°CSoldering Temperature (reflow) .......................................+260°CLead Temperature ...........................................................+300°C
32 TQFNPACKAGE CODE T3255
Outline Number 21-0140Land Pattern Number 90-0015Thermal Resistance, Four-Layer Board:Junction to Ambient (θJA) 40.2°C/WJunction to Case (θJC) 2.0°C/W
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.
Package Information
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
VCCI = +3.0V to +5.5V, VGND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSVOLTAGE REFERENCE 2.5VSTATICSupply Voltage VCCI Guaranteed by line regulation test 3.0 5.5 V
VCCI Line Regulation ∆VREF/∆VCCI
3.0V ≤ VCCI ≤ 5.5V 20 140 µV/V
VCC Line Regulation ∆VREF/∆VCC
4.3V ≤ VCC ≤ 36V, VCCI = 3.3V 1.2 nV/V
Output Voltage VOUT TA = +25°C 2.495 2.500 2.505 V
Output Voltage Temperature Coefficient TCVOUT CREF = 2nF (Note 2) 2 10 ppm/°C
Temperature Hysteresis ∆VREF/Cycle CREF = 2nF -140 ppm
Load Regulation ∆VREF/∆IOUT
Sourcing 0V ≤ IOUT ≤ 500 µA 0.14 0.6 µV/µA
Short-Circuit Current ISC Short to GND 3 mA
Maximum Capacitive Load CREF 2 nF
DYNAMIC
VCCI Ripple Rejection VREF/VCCI
VCCI = 3.3V, f = 120Hz 90 dB
VCC Ripple Rejection VREF/VCC
VCC = 12V, VCCI = 3.3V, f = 120Hz 160 dB
Turn-On Settling Time tRFrom 90% of VCCI to within 0.1% of VREF, CREF = 2nF 85 µs
Noise Voltage eREF0.1Hz to 10Hz 40 µVp-p10Hz to 10kHz 125 µVRMS
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical CharacteristicsVoltage Reference
VCCI = +3.0V to +5.5V, VGND = 0V, outputs connected to 100kΩ in parallel with 10pF terminated to VREF/2, input pulses have 10ns rise and fall times, PWM period = 100µs, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSPWMA, PWMBSTATICSupply Voltage VCCI Guaranteed by PSRRVOH test 3.0 5.5 V
VCCI Supply Rejection Ratio of Input Threshold Voltage
PSRRVTH 3.0V ≤ VCCI ≤ 5.5V 65 dB
VCC Supply Rejection Ratio of Input Threshold Voltage
4.3V ≤ VCC ≤ 36V, VCCI = 3.3V 150 dB
VCCI Supply Rejection Ratio of Output Voltage High
PSRRVOH 3.0V ≤ VCCI ≤ 5.5V, no load 59 75 dB
VCC Supply Rejection Ratio of Output Voltage High
4.3V ≤ VCC ≤ 36V, VCCI = 3.3V, no load 160 dB
Input Voltage Range 0 VCCI VInput Voltage High VIH PWMAP, PWMBP, SHDN 1.4 VInput Voltage Low VIL PWMAP, PWMBP, SHDN 0.6 V
PWMAP, PWMBP Input Threshold VTH 1.0 V
PWMAP, PWMBP Input Threshold Accuracy 1 mV
PWMAP, PWMBP Hysteresis PWMHYS 5 mV
SHDN Hysteresis SHDNHYS 50 mVInput Bias Current IB VPWMAP = VPWMBP = 0V -1 nAInput Capacitance CIN 2 pFOutput Voltage High VOH VREF - VOUT, ISOURCE = 100 µA 0.1 VOutput Voltage Low VOL VOUT – VGND, ISINK = 100 µA 0.1 V
Short Circuit Current ISCPWMAO or PWMBO short to VREF -12 mAPWMAO or PWMBO short to GND 6 mA
Output High Level Voltage Matching
Difference between the voltage of the two PWM outputs -2 +2 mV
Output Low Level Voltage Matching
Difference between the voltage of the two PWM outputs -2 +2 mV
PWMAO, PWMBO Output Voltage High Drift
7 µV/°C
Linearity From code 10 to code 245 (Note 2), Figure 1 0.01 %FSR
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)PWM Conditioners
VCCI = +3.0V to +5.5V, VGND = 0V, outputs connected to 100kΩ in parallel with 10pF terminated to VREF/2, input pulses have 10ns rise and fall times, PWM period = 100µs, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDYNAMICPropagation Delay Active to Shut down tSHDN
From 50% of SHDN to when PWM outputs are Hi-Z 10 µs
Propagation Delay Shut down to Active tACT
From 50% of SHDN to when PWM outputs are active 10 µs
Minimum Input Pulse Width IPW
Single high state, guaranteed by PWM timing tests 390 ns
Driver Rise Time for PWMAO and PWMBO RTA, RTB
Single 390ns pulse, 10% to 90% 7 ns
Driver Fall Time for PWMAO and PWMBO FTA, FTB 6 ns
PWMAO to PWMBO Rise Time Matching Single 390ns pulse -4 +4 ns
PWMAO to PWMBO Fall Time Matching Single 390ns pulse -2 +2 ns
PWMAO to PWMBO Delay Matching
Single 390ns pulse, measured at 50% FSR of rising edges -30 +30 ns
PWMAO and PWMBO Pulse Width Accuracy
Single 390ns pulse, pulse width difference between input and output waveforms (measured at 50% points)
-30 +30 ns
PWMAO and PWMBO Pulse Width Variation vs. Temperature
Single 390ns pulse 25 ps/°C
PWMAO and PWMBO Pulse Width Matching
Single 390ns pulse, difference between PWMAO and PWMBO pulse widths -30 +30 ns
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)PWM Conditioners (continued)
VCCI = +3.0V to +5.5V, VGND = 0V, VCM = VOUT = VCCI/2, no resistive load, CL = 10pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSOP1, OP2STATICSupply Voltage VCCI Guaranteed by PSRRVCCI test 3.0 5.5 V
VCCI Supply Rejection Ratio PSRRVCCI 3.0V ≤ VCCI ≤ 5.5V 62 80 dB
VCC Supply Rejection Ratio PSRRVCC 4.3V ≤ VCC ≤ 36V, VCCI = 3.3V 165 dB
Common Mode Input Voltage
VCMR
Guaranteed by CMRR testVCCI ≤ 4.5V -0.1 VCCI -
0.5 V
Guaranteed by CMRR test4.5V ≤ VCCI ≤ 5.5V -0.1 +4.0 V
Common Mode Rejection Ratio CMRR -0.1V ≤ VCM ≤ min (4.0V, VCCI - 0.5V) 56 dB
Input Offset Voltage VOS 1 mV
Input Offset Voltage Drift ∆VOS (Note 2) 15 µV/°C
Input Bias Current IB-40°C ≤ TA ≤ +85°C (Note 2) -15 +15 pA
-40°C ≤ TA ≤ +125°C (Note 2) -125 +125 pA
Input Offset Current IOS-40°C ≤ TA ≤ +85°C (Note 2) -15 +15 pA
-40°C ≤ TA ≤ +125°C (Note 2) -80 +80 pA
Open-Loop Gain AVOL
150mV ≤ VOUT ≤ VCCI - 150mV, RL = 100kΩ connected to VCCI / 2, -40°C ≤ TA ≤ +85°C
78 dB
-40°C ≤ TA ≤ +125°C 72
Output Voltage High VOHVCCI – VOUT,RL = 100kΩ connected to VCCI / 2
25 mV
Output Voltage Low VOLVOUT - VGND, RL = 100kΩ connected to VCCI / 2
25 mV
Output Short-Circuit Current IOUT(SC) ±3 mA
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)Op Amps
VCCI = +3.0V to +5.5V, VGND = 0V, VCM = VOUT = VCCI/2, no resistive load, CL = 10pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDYNAMICInput Voltage Noise Density eN f = 1kHz 150 nV/√Hz
Input Current Noise Density iN f = 1kHz 40 fA/√Hz
Gain Bandwith Product GBWP 200 kHzSlew Rate SR 0.1 V/ µsSettling Time To 0.1%, VOUT = 2V step, AV = -1V/V 25 µs
Maximum Capacitive Load CL No sustained oscillations, AV = 1V/V 100 pF
OP3 (RL = 100kΩ CONNECTED to VCCI/2, CL = 20pF)STATICSupply Voltage VCCI Guaranteed by PSRRVCCI test 3.0 5.5 V
VCCI Supply Rejection Ratio PSRRVCCI 3.0V ≤ VCCI ≤ 5.5V 107 dB
VCC Supply Rejection Ratio PSRRVCC 4.3V ≤ VCC ≤ 36V, VCCI = 3.3V 195 dB
Common Mode Input Voltage VCMR
Guaranteed by CMRR test VCCI ≤ 4.3V -0.1 VCCI -
0.3 V
Guaranteed by CMRR test 4.3V ˂ VCCI ≤ 5.5V -0.1 +4.0 V
Common Mode Rejection Ratio CMRR -0.1V ≤ VCM ≤ min(4.0V, VCCI - 0.3V) 105 dB
Input Offset Voltage VOS TA = 25°C, VCCI = 3.3V (Note 2) -10 +10 µV
Input Offset Voltage Drift ∆VOS (Note 2) 5 70 nV/°C
Input Bias Current IB-40°C ≤ TA ≤ +85°C (Note 2) -15 +15 pA
-40°C ≤ TA ≤ +125°C (Note 2) -125 +125 pAInput Offset Current IOS -40 pA
Input Capacitance CIN 2 pF
Open-Loop Gain AVOL 150mV ≤ VOUT ≤ VCCI-150mV, RL = 5kΩ connected to VCCI / 2
123 150 dB
Output Voltage High VOHVCCI – VOUT,RL = 100kΩ connected to VCCI / 2
12 mV
Output Voltage Low VOLVOUT - VGND, RL = 100kΩ connected to VCCI / 2
12 mV
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)Op Amps (continued)
VCCI = +3.0V to +5.5V, VGND = 0V, VCM = VOUT = VCCI/2, no resistive load, CL = 10pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCCI = +3.3V. (Note 1)
VCCI = +3.0V to +5.5V, VDD = +1.8V to +3.6V, VGND = 0V, VCM = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VDD = VCCI = +3.3V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDYNAMICInput Voltage Noise Density eN f = 1kHz 35 nV/√Hz
Input Voltage Noise 0.1Hz ≤ f ≤ 10Hz 0.7 µVp-p
Input Current Noise Density iN f = 1kHz 80 fA/√Hz
Gain Bandwidth Product GBWP 2.2 MHz
Slew Rate SR 0.7 V/µsPhase Margin 57 °
Maximum Capacitive Load CL No sustained oscillations, AV = 1V/V 300 pF
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSCOMP1, COMP2STATICSupply Voltage VCCI Guaranteed by PSRRVCCI test 3.0 5.5 V
Supply Voltage Output Stage VDD 1.8 3.6 V
VCCI Supply Rejection Ratio PSRRVCCI 3.0V ≤ VCCI ≤ 5.5V 54 dB
VCC Supply Rejection Ratio PSRRVCC 4.3V ≤ VCC ≤ 36V, VCCI = 3.3V 160 dB
Common Mode Input Voltage
VCMR Guaranteed by CMRR test 0 VCCI - 1.3 V
Common Mode Rejection Ratio CMRR 0V ≤ VCM ≤ VCCI – 1.3V 56 75 dB
Input Offset Voltage VOS -10 +10 mVHysteresis VHYS 15 mVInput Bias Current IB VCM = 0V -10 -1 nAInput Offset Current IOS 1 nAInput Capacitance CIN 2 pFOutput Voltage High VOH VDD - VOUT, ISOURCE = 100 µA 0.4 V
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)
Electrical Characteristics (continued)
Op Amps (continued)
Comparators
VCCI = +3.0V to +5.5V, VDD = +1.8V to +3.6V, VGND = 0V, VCM = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VDD = VCCI = +3.3V. (Note 1)
VCC = +4.0V to +36V, VGND = 0V, CLOAD = 0.32µF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCC = +24V. (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSOutput Voltage Low VOL VOUT – VGND, ISINK = 100 µA 0.4 V
Short Circuit Current ISCShort to GND 2 mAShort to VDD -2 mA
DYNAMICPropagation Delay Low to High tPD+
CLOAD = 10pF, threshold set to VCCI -1.4V, input swings from 0V to VCCI -1.3V 2 µs
Propagation Delay High to Low tPD-
CLOAD = 10pF, threshold set to 0.1V, input swings from VCCI -1.3V to 0V 0.5 µs
Rise Time TR CLOAD= 10pF 50 nsFall Time TF CLOAD= 10pF 50 ns
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSLDOSTATICSupply Voltage VCC Guaranteed by line regulation test 4.0 24 36 VDropout Voltage Guaranteed by line and load regulation tests 1 V
VCC Line Regulation VCC from VCCI+1V to 36V, ILDO = 4mA, VCCI = 3.0V to 5.5V 2 25 mV
Output Voltage VCCI Guaranteed by block PSRRVCCI tests 3.0 5.5 V
Output Voltage Accuracy
VCC = 24V, no load except for LDOFB resistor divider, VCCI = 3.3V -3.5 +3.5 %
Output Current Range ILDO Guaranteed by load regulation test 0 4 mAVCCI Current Limit ICCI_Limit VCCI short to GND 12 mA
Load Regulation VCC = VCCI+1V, ILDO from 0mA to 4mA,VCCI = 3.0V to 5.5V 1 10 mV
Maximum Capacitive Load CLOAD
No resistive load except for LDOFB resistor divider 5 µF
DYNAMICVCC Supply Rejection Ratio PSRR VCC = 12V, DC to 120Hz 70 dB
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)Comparators (continued)
LDO
VCC = +4.0V to +36V, VCCI = +3.0V to +5.5V, VDD = +1.8V to +3.6V, VGND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C, VCC = +24V, VDD = VCCI = +3.3V. (Note 1)
Note 1: Specifications are 100% tested at TA = +25°C (exceptions noted). All temperature limits are guaranteed by design.Note 2: Guaranteed by design, not production tested.
Figure 1. Typical PWM Timing Diagram
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSSTATIC
VCC Supply Current ICC
VCC = 24V, VCCI = 3.3V, SHDN = 3.3V, no load,-40°C ≤ TA ≤ +85°C 170 250 µA
-40°C ≤ TA ≤ +125°C 265 µA
VCC Supply Current with PWM Conditioners Shutdown
ICC_SHDN VCC = 24V, VCCI = 3.3V, SHDN = 0V, no load 142 µA
VDD Supply Current IDD 1 µA
PWRGOOD Turn-on Threshold 90 % of
VCCI
PWRGOOD Turn-off Threshold 80 % of
VCCI
PWRGOOD Voltage High VOH VCCI – VOUT, ISOURCE = 100 µA 0.4 V
PWRGOOD Voltage Low VOL VOUT – VGND, ISINK = 100 µA 0.4 V
PWRGOOD Short Circuit Current ISC
Short to GND 2 mAShort to VCCI -2 mA
DYNAMICPWRGOOD Turn-on Delay
From VCCI crossing turn-on threshold to PWRGOOD high 0.7 ms
256 STEPS
0.1ms
0.1ms/256 PWMAPPWMBP
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Electrical Characteristics (continued)Chip-Level Specifications
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
1 10 100 1k 10k 100k0
2
4
6
8
10
12
14
16
18
20
LOO
P CU
RREN
T NO
ISE
DENS
ITY
(nA/
√Hz)
FREQUENCY (Hz)
4mA LOOP CURRENT NOISEDENSITY vs. FREQUENCY
OVER 500Ω LOAD toc08
-0.020
-0.015
-0.010
-0.005
0.000
0.005
0.010
0.015
0.020
0 20 40 60 80
LOO
P CU
RREN
T LI
NEAR
ITY
(%FS
)
PWM DUTY CYCLE (%)
16V 24V 32V 36V
4-20mA LINEARITY vs. PWM DUTY CYCLE AND
LOOP VOLTAGEtoc04
VLOOP = 24VRLOAD = 100Ω
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0 10 20 30 40 50 60 70 80 90 100
LOO
P CU
RREN
T (m
A)
DUTY CYCLE (%)
TRANSFER CHARACTERISTICSLOOP CURRENT vs. PWM DUTY CYCLE
toc01
VLOOP = 24VRLOAD = 250Ω
4mA LOOP CURRENT NOISEDURING SILENCEOVER 500Ω LOAD
100ms/div
10mV/div
toc07
VOUTN
VINSIDE
VBACKUP
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0 0.5 1 1.5 2 2.5
LOO
P CU
RREN
T (m
A)
OP3 INPUT (V)
TRANSFER CHARACTERISTICSLOOP CURRENT vs. OP3 INPUT
toc02
VLOOP = 24VRLOAD = 250Ω
-0.020
-0.015
-0.010
-0.005
0.000
0.005
0.010
0.015
0.020
0 20 40 60 80
LOO
PCU
RREN
TLI
NEAR
ITY
(%FS
)
PWM DUTY CYCLE (%)
-40°C 25°C 85°C 125°C
4-20mA LINEARITY vs.PWM DUTY CYCLE
AND TEMPERATUREtoc03
VLOOP = 24VRLOAD = 100Ω
10 100 1k 10k 100k 1M0
10
20
30
40
50
60
70
PSRR
(dB)
FREQUENCY (Hz)
VCC SUPPLY REJECTIONRATIO vs. FREQUENCY
(SYSTEM LEVEL) toc09
0
50
100
150
200
250
300
350
400
-40 -25 -10 5 20 35 50 65 80 95 110 125
VCC
SUPP
LY C
URRE
NT (
µA)
TEMPERATURE (°C)
4mA 12mA 20mA
VCC SUPPLY CURRENT(SYSTEM LEVEL)
vs. TEMPERATUREtoc05
RLOAD = 100Ω
0
50
100
150
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350
400
16 21 26 31 36
VCC
SUPP
LY C
URRE
NT (
µA)
VCC VOLTAGE (V)
4mA 12mA 20mA
VCC SUPPLY CURRENTvs. SUPPLY VOLTAGE
toc06
RLOAD = 100Ω
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MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
HART COMMUNICATION
2ms/div
200mV/div(AC-COUPLED)
toc13
VOUTN
VINSIDE
VBACKUP
10 100 1k 10k 100k 1M0
10
20
30
40
50
60
70
PSRR
(dB)
FREQUENCY (Hz)
LOOP SUPPLY REJECTIONRATIO vs. FREQUENCY
(SYSTEM LEVEL) toc10
20mASTEP TRANSIENTRESPONSE OVER 500Ω LOAD
20ms/div
2V/div
toc11
VOUTN
VINSIDE
VBACKUP
ANALOG RATE OF CHANGE OVER 500Ω LOAD
WITH DIGITAL FILTER
20ms/div
200mV/div10x gain(AC COUPLED)
toc12
VOUTN
VINSIDE
VBACKUP
10kHZ SQUARE WAVE OVER 100Ω LOAD
100mV/div(AC-COUPLED)
50µs/div
toc14
VOUTN
VINSIDE
VBACKUP
0
5
10
15
20
25
30
-1800 -1200 -600 0 600 1200 1800
FREQ
UENC
Y (%
)
INPUT OFFSET VOLTAGE (µV)
OP1/OP2 INPUT OFFSETVOLTAGE HISTOGRAM
toc15
Maxim Integrated 13www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
10
100
1000
10000
0.1 1 10 100 1000 10000
CAP
ACIT
ANC
E (p
F)
ISOLATION RESISTOR (Ω)
toc22
UNSTABLE
VCCI = 3.3VVCM = 1.65VAV = 1V/VRLOAD = ∞
OP1/OP2 CAPACITIVE LOADvs. ISOLATION RESISTOR
3.290
3.291
3.292
3.293
3.294
3.295
3.296
3.297
3.298
3.299
3.300
-40 -25 -10 5 20 35 50 65 80 95 110 125
OU
TPU
T VO
LTAG
E (V
)
TEMPERATURE (°C)
OP1/OP2 OUTPUT VOLTAGEHIGH vs. TEMPERATURE
toc19
RLOAD = 100kΩ
0
1
2
3
4
5
6
7
8
9
10
-40 -25 -10 5 20 35 50 65 80 95 110 125
OU
TPU
T VO
LTAG
E (m
V)
TEMPERATURE (°C)
OP1/OP2 OUTPUT VOLTAGELOW vs. TEMPERATURE
toc20
RLOAD = 100kΩ
10m 100m 1 10 100 1k 10k 100k 1M-225
-180
-135
-90
-45
0
45
90
135
180
225
-60
-40
-20
0
20
40
60
80
100
120
140
PHAS
E(°
)
GAI
N(d
B)
FREQUENCY (Hz)
GAIN
OP1/OP2 GAIN AND PHASEvs. FREQUENCY
toc21
AV = 1V/VRLOAD = 100kΩCLOAD = 10pF
PHASE
1.50
1.55
1.60
1.65
1.70
1.75
1.80
0 10 20 30 40 50 60 70 80 90 100
OU
TPU
T VO
LTAG
E (V
)
TIME (µs)
OP1/OP2 SMALL-SIGNALPULSE RESPONSE
toc23
AV = 1V/VCLOAD = 15pF
0.33
0.66
0.99
1.32
1.65
1.98
2.31
2.64
2.97
0 10 20 30 40 50 60 70 80 90 100
OU
TPU
T VO
LTAG
E (V
)
TIME (µs)
OP1/OP2 LARGE-SIGNALPULSE RESPONSE
toc24
AV = 1V/VCLOAD = 15pF
0
5
10
15
20
25
30
35
0 0.04 0.08 0.12 0.16
FREQ
UEN
CY
(%)
INPUT BIAS CURRENT (pA)
OP1/OP2 INPUT BIASCURRENT HISTOGRAM
toc16
VCCI = 5.5VVCM = 2.75VTA = +25°C
-600
-400
-200
0
200
400
600
800
-0.1 0.4 0.9 1.4 1.9 2.4 2.9
INPU
T O
FFSE
T VO
LTAG
E (µ
V)
INPUT COMMON-MODE VOLTAGE (V)
-40°C 25°C 85°C 125°C
OP1/OP2 INPUT OFFSET VOLTAGEvs. COMMON-MODE VOLTAGE
toc17
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
0 0.5 1 1.5 2 2.5 3
INPU
T BI
AS C
UR
REN
T (p
A)
INPUT COMMON-MODE VOLTAGE (V)
-40°C 25°C 85°C 125°C
OP1/OP2 INPUT BIAS CURRENTvs. COMMON-MODE VOLTAGE
toc18
Maxim Integrated 14www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
10
100
1000
10000
0.01 0.1 1 10 100
INPU
T VO
LTAG
E NO
ISE
(nV/
√Hz)
FREQUENCY (kHz)
toc25
AV = 4V/V
OP1/OP2 INPUT VOLTAGENOISE vs. FREQUENCY
1 10 100 1k 10k 100k0
10
20
30
40
50
60
70
80
90
PSRR
(dB)
FREQUENCY (Hz)
OP1/OP2 VCCI SUPPLY REJECTIONRATIO vs. FREQUENCY toc26
1 10 100 1k 10k 100k0
20
40
60
80
100
120
140
160
180
PSRR
(dB)
FREQUENCY (Hz)
OP1/OP2 VCC SUPPLY REJECTIONRATIO vs. FREQUENCY toc27
0
5
10
15
20
25
-5.8 -5.2 -4.6 -4.0 -3.4 -2.8 -2.2
FREQ
UENC
Y (%
)
INPUT OFFSET VOLTAGE (µV)
OP3 INPUT OFFSETVOLTAGE HISTOGRAM
toc28
0
5
10
15
20
25
3.31 3.42 3.53 3.64 3.75 3.86
FREQ
UENC
Y (%
)
INPUT BIAS CURRENT (pA)
OP3 INPUT BIASCURRENT HISTOGRAM
toc29
VCCI = 5.5VVCM = 2.75VTA = +25°C
-9
-7
-5
-3
-1
1
3
-0.1 0.3 0.7 1.1 1.5 1.9 2.3 2.7 3.1
INPU
T O
FFSE
T VO
LTAG
E (µ
V)
INPUT COMMON-MODE VOLTAGE (V)
-40°C 25°C 85°C 125°C
OP3 INPUT OFFSET VOLTAGEvs. COMMON-MODE VOLTAGE
toc30
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
0 0.5 1 1.5 2 2.5 3
INPU
T BI
AS C
URRE
NT (
pA)
INPUT COMMON-MODE VOLTAGE (V)
-40°C 25°C 85°C 125°C
OP3 INPUT BIAS CURRENTvs. COMMON-MODE VOLTAGE
toc31
3.295
3.296
3.297
3.298
3.299
3.300
3.301
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
(V)
TEMPERATURE (°C)
OP3 OUTPUT VOLTAGEHIGH vs. TEMPERATURE
toc32
RLOAD = 100kΩ
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
(mV)
TEMPERATURE (°C)
OP1/OP2 OUTPUT VOLTAGELOW vs. TEMPERATURE
toc33
RLOAD = 100kΩ
Maxim Integrated 15www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
10m 100m 1 10 100 1k 10k 100k 1M 10M-180
-135
-90
-45
0
45
90
135
180
225
270
-40
-20
0
20
40
60
80
100
120
140
160PH
ASE
(°)
GAI
N (d
B)
FREQUENCY (Hz)
GAIN
OP3 GAIN AND PHASEvs. FREQUENCY toc34
AV = 1V/VRLOAD = 100kΩCLOAD = 20pF
PHASE
100
1000
10000
0.1 1 10 100 1000 10000
CAPA
CITA
NCE
(pF)
ISOLATION RESISTOR (Ω)
toc35
UNSTABLE
VCCI = 3.3VVCM = 1.65VAV = 1V/VRLOAD = 100kΩ
OP3 CAPACITIVE LOADvs. ISOLATION RESISTOR
1.50
1.55
1.60
1.65
1.70
1.75
1.80
0 10 20 30 40 50 60 70 80 90 100
OUT
PUT
VOLT
AGE
(V)
TIME (µs)
OP3 SMALL-SIGNALPULSE RESPONSE
toc36
AV = 1V/VCLOAD = 15pF
1 10 100 1k 10k 100k 1M0
10
20
30
40
50
60
70
80
90
100
110
120
PSRR
(dB)
FREQUENCY (Hz)
OP3 VCCI SUPPLY REJECTIONRATIO vs. FREQUENCY toc40
0.33
0.66
0.99
1.32
1.65
1.98
2.31
2.64
2.97
0 10 20 30 40 50 60 70 80 90 100
OUT
PUT
VOLT
AGE
(V)
TIME (µs)
OP3 LARGE-SIGNALPULSE RESPONSE
toc37
AV = 1V/VCLOAD = 15pF
2.5000
2.5005
2.5010
2.5015
2.5020
2.5025
2.5030
3 3.5 4 4.5 5 5.5
OUT
PUT
VOLT
AGE
(V)
VCCI (V)
-40°C 25°C 85°C 125°C
VOLTAGE REFERENCELINE REGULATION
toc42
10
100
1000
10000
0.01 0.1 1 10 100
INPU
T VO
LTAG
E NO
ISE
(nV/
√Hz)
FREQUENCY (kHz)
toc38
OP3 INPUT VOLTAGENOISE vs. FREQUENCY
1s/div
OP3 0.1Hz TO 10HzINPUT VOLTAGE NOISE
toc39
0.1µV/div
1 10 100 1k 10k 100k 1M0
20
40
60
80
100
120
140
160
180
200
PSRR
(dB)
FREQUENCY (Hz)
OP3 VCC SUPPLY REJECTIONRATIO vs. FREQUENCY toc41
Maxim Integrated 16www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
2.4985
2.4990
2.4995
2.5000
2.5005
2.5010
2.5015
2.5020
2.5025
0 100 200 300 400 500
OUT
PUT
VOLT
AGE
(V)
ILOAD (µA)
-40°C 25°C 85°C 125°C
VOLTAGE REFERENCELOAD REGULATION
toc43
VCCI = 5.5V
2.4985
2.4990
2.4995
2.5000
2.5005
2.5010
2.5015
2.5020
2.5025
0 100 200 300 400 500
OUT
PUT
VOLT
AGE
(V)
ILOAD (µA)
-40°C 25°C 85°C 125°C
VOLTAGE REFERENCELOAD REGULATION
toc44
VCCI = 3.0V
20µs/div
VOLTAGE REFERENCE LOADTRANSIENT RESPONSE
toc48
AC-COUPLED
ILOAD25µA/div
VREFO20mV/div
+25µA
-25µA
0
5
10
15
20
25
30
35
0.4 1.3 2.2 3.1 4.0 4.9 5.8
FREQ
UENC
Y (%
)
TEMPERATURE COEFFICIENT (ppm/°C)
VOLTAGE REFERENCE TEMPERATURECOEFFICIENT HISTOGRAM
toc45
0
5
10
15
20
25
-278 -234 -190 -146 -102 -58 -14
FREQ
UENC
Y (%
)
TEMPERATURE HYSTERESIS (ppm)
VOLTAGE REFERENCE TEMPERATUREHYSTERESIS HISTOGRAM
toc46
100µs/div
VOLTAGE REFERENCE LINETRANSIENT RESPONSE
toc47
VVCC2V/div
VREFO10mV/div
+20V
AC-COUPLEDCLDO = 0.32µF
+10V
1 10 100 1k 10k 100k 1M0
10
20
30
40
50
60
70
80
90
100
PSRR
(dB)
FREQUENCY (Hz)
VOLTAGE REFERENCE VCCI REJECTIONRATIO vs. FREQUENCY toc49
1s/div
VOLTAGE REFERENCE0.1Hz TO 10Hz OUTPUT NOISE
toc51
10µV/div
1 10 100 1k 10k 100k 1M0
20
40
60
80
100
120
140
160
180
PSRR
(dB)
FREQUENCY (Hz)
VOLTAGE REFERENCE VCC REJECTIONRATIO vs. FREQUENCY toc50
Maxim Integrated 17www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
0.1
1.0
10.0
100.0
0.01 0.1 1 10 100
VOLT
AGE
REFE
RENC
E NO
ISE
(µV/
√Hz)
FREQUENCY (kHz)
toc52
VOLTAGE REFERENCENOISE vs. FREQUENCY
0.997
0.998
0.999
1.000
1.001
-40 -25 -10 5 20 35 50 65 80 95 110 125
INPU
T TH
RESH
OLD
VO
LTAG
E (V
)
TEMPERATURE (°C)
PWMA/PWMB INPUT THRESHOLDVOLTAGE vs. TEMPERATURE
toc53
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
MAT
CHIN
G (
mV)
TEMPERATURE (°C)
PWMA-PWMB OUTPUT HIGH LEVELMATCHING vs. TEMPERATURE
toc57
RLOAD = 100kΩ
-0.40
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
-40 -25 -10 5 20 35 50 65 80 95 110 125
INPU
T BI
AS C
URRE
NT (
nA)
TEMPERATURE (°C)
PWMA/PWMB INPUT BIASCURRENT vs. TEMPERATURE
toc54
2.480
2.482
2.484
2.486
2.488
2.490
2.492
2.494
2.496
2.498
2.500
0 50 100 150 200
OUT
PUT
VOLT
AGE
(V)
ILOAD (µA)
-40°C 25°C 85°C 125°C
PWMA/PWMB OUTPUT VOLTAGEHIGH vs. LOAD CURRENT
toc60
2.495
2.496
2.497
2.498
2.499
2.500
2.501
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
(V)
TEMPERATURE (°C)
PWMA/PWMB OUTPUT VOLTAGEHIGH vs. TEMPERATURE
toc55
RLOAD = 100kΩ
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
(mV)
TEMPERATURE (°C)
PWMA/PWMB OUTPUT VOLTAGELOW vs. TEMPERATURE
toc56
RLOAD = 100kΩ
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
MAT
CHIN
G (
mV)
TEMPERATURE (°C)
PWMA-PWMB OUTPUT LOW LEVELMATCHING vs. TEMPERATURE
toc58
RL = 100kΩ
0
2
4
6
8
10
12
14
16
-200 -150 -100 -50 0
OUT
PUT
VOLT
AGE
(mV)
ILOAD (µA)
-40°C 25°C 85°C 125°C
PWMA/PWMB OUTPUT VOLTAGELOW vs. LOAD CURRENT
toc59
Maxim Integrated 18www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
-13.0
-12.5
-12.0
-11.5
-11.0
-10.5
-10.0
-9.5
-9.0
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
CURR
ENT
FRO
M V
REF
(mA)
CURR
ENT
TO G
ND (m
A)
TEMPERATURE (°C)
SHORT TO GND SHORT TO VREF
PWMA/PWMB SHORT-CIRCUITCURRENT vs. TEMPERATURE
toc61
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 200 400 600 800 1000
VOLT
AGE
(V)
TIME (ns)
INPUT OUTPUT
PWMA/PWMB INPUT/OUTPUTWAVEFORMS
toc62
CODE = 1CLOAD = 10pF
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
PULS
E W
IDTH
MAT
CHIN
G (
ns)
TEMPERATURE (°C)
5% DUTY CYCLE50% DUTY CYCLE95% DUTY CYCLE
PWMA-PWMB PULSE WIDTHMATCHING vs. TEMPERATURE
toc66
RLOAD = 100kΩCLOAD = 10pFPERIOD = 100µs
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 1 2 3 4 5 6 7
VOLT
AGE
(V)
TIME (µs)
INPUT OUTPUT
PWMA/PWMB INPUT/OUTPUTWAVEFORMS
toc63
CODE = 10CLOAD = 10pF
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
PRO
PAG
ATIO
N DE
LAY
MAT
CHIN
G (
ns)
TEMPERATURE (°C)
PWMA-PWMB PROPAGATION DELAYMATCHING vs. TEMPERATURE
toc64
RLOAD = 100kΩCLOAD = 10pF
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
-40 -25 -10 5 20 35 50 65 80 95 110 125
RISE
AND
FAL
L TI
ME
MAT
CHIN
G (
ns)
TEMPERATURE (°C)
RISE TIME MATCHING
FALL TIME MATCHING
PWMA-PWMB RISE AND FALL TIMEMATCHING vs. TEMPERATURE
toc65
RLOAD = 100kΩCLOAD = 10pF
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
-40 -25 -10 5 20 35 50 65 80 95 110 125
INPU
T O
FFSE
T VO
LTAG
E (m
V)
TEMPERATURE (°C)
COMP1/COMP2 INPUT OFFSETVOLTAGE vs. TEMPERATURE
toc67
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
-40 -25 -10 5 20 35 50 65 80 95 110 125
INPU
T BI
AS C
URRE
NT (
nA)
TEMPERATURE (°C)
COMP1/COMP2 INPUT BIASCURRENT vs. TEMPERATURE
toc68
0
50
100
150
200
250
300
350
-200 -150 -100 -50 0
OUT
PUT
VOLT
AGE
(mV)
ILOAD (µA)
-40°C 25°C 85°C 125°C
COMP1/COMP2 OUTPUT VOLTAGELOW vs. LOAD CURRENT
toc69
Maxim Integrated 19www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
2.95
3.00
3.05
3.10
3.15
3.20
3.25
3.30
3.35
0 50 100 150 200
OUT
PUT
VOLT
AGE
(V)
ILOAD (µA)
-40°C 25°C 85°C 125°C
COMP1/COMP2 OUTPUT VOLTAGEHIGH vs. LOAD CURRENT
toc70
400
600
800
1000
1200
1400
1600
1800
2000
2200
-40 -25 -10 5 20 35 50 65 80 95 110 125
PRO
PAG
ATIO
N DE
LAY
(ns)
TEMPERATURE (°C)
LOW TO HIGH
HIGH TO LOW
COMP1/COMP2 PROPAGATIONDELAY vs. TEMPERATURE
toc74
CLOAD = 10pF
-2.12
-2.10
-2.08
-2.06
-2.04
-2.02
-2.00
-1.98
1.98
2.00
2.02
2.04
2.06
2.08
2.10
2.12
-40 -25 -10 5 20 35 50 65 80 95 110 125
CURR
ENT
FRO
M V
DD(m
A)
CURR
ENT
TO G
ND (m
A)
TEMPERATURE (°C)
SHORT TO GND SHORT TO VDD
COMP1/COMP2 SHORT-CIRCUITCURRENT vs. TEMPERATURE
toc71
3.296
3.300
3.304
3.308
3.312
3.316
3.320
3.324
0 0.5 1 1.5 2 2.5 3 3.5 4
OUT
PUT
VOLT
AGE
(V)
ILDO (mA)
-40°C 25°C 85°C 125°C
LDO LOAD REGULATIONtoc77
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 0.5 1 1.5 2 2.5 3
VOLT
AGE
(V)
TIME (µs)
POSITIVE INPUT
NEGATIVE INPUT
OUTPUT
COMP1/COMP2 INPUT/OUTPUTWAVEFORMS (TPD+)
toc72
CLOAD = 10pF
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 0.25 0.5 0.75 1 1.25 1.5
VOLT
AGE
(V)
TIME (µs)
POSITIVE INPUT
NEGATIVE INPUT
OUTPUT
COMP1/COMP2 INPUT/OUTPUTWAVEFORMS (TPD-)
toc73
CLOAD = 10pF
3.300
3.302
3.304
3.306
3.308
3.310
3.312
3.314
3.316
3.318
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUT
PUT
VOLT
AGE
(V)
TEMPERATURE (°C)
0.1mA LOAD 4mA LOAD
LDO OUTPUT VOLTAGEvs. TEMPERATURE
toc78
3.290
3.295
3.300
3.305
3.310
3.315
3.320
3.325
3.330
4 8 12 16 20 24 28 32 36
OUT
PUT
VOLT
AGE
(V)
VCC (V)
-40°C 25°C 85°C 125°C
LDO LINE REGULATIONtoc75
ILDO = 0.1mA
3.290
3.295
3.300
3.305
3.310
3.315
3.320
3.325
3.330
4 8 12 16 20 24 28 32 36
OUT
PUT
VOLT
AGE
(V)
VCC (V)
-40°C 25°C 85°C 125°C
LDO LINE REGULATIONtoc76
ILDO = 4mA
Maxim Integrated 20www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
VCC = +24V, VDD = VCCID = VCCI = +3.3V, GND = 0V, op amp VCM = VOUT = VCCI/2, op amp CL = 15pF, comparator and PWM CL = 10pF, LDO CLOAD = 0.32µF, no resistive load on any output, TA = +25°C, unless otherwise noted.
100µs/div
VCC VCCI
LDO LINETRANSIENT RESPONSE
toc79
AC-COUPLEDCLOAD = 0.32µF
VVCC2V/div
VVCCI20mV/div
+15V
+9V
105
115
125
135
145
155
165
175
185
195
4 8 12 16 20 24 28 32 36
SUPP
LY C
URRE
NT (
µA)
VCC (V)
-40°C 25°C 85°C 125°C
QUIESCENT CURRENTvs. VCC VOLTAGE
toc83
PWM CONDITIONERS SHUT DOWN
40µs/div
LOAD CURRENT
VCCI
LDO LOADTRANSIENT RESPONSE
toc80
AC-COUPLEDCLOAD = 0.32µF
ILDO2mA/div
VVCCI20mV/div
+4.0mA
+0.4mA
1 10 100 1k 10k 100k 1M0
10
20
30
40
50
60
70
80
90
100
PSRR
(dB)
FREQUENCY (Hz)
LDO VCC SUPPLY REJECTIONRATIO vs. FREQUENCY toc81
CLOAD = 0.32µFR1 = 510kΩR2 = 300kΩ
130
140
150
160
170
180
190
200
210
220
4 8 12 16 20 24 28 32 36
SUPP
LY C
URRE
NT (
µA)
VCC (V)
-40°C 25°C 85°C 125°C
QUIESCENT CURRENTvs. VCC VOLTAGE
toc82
140
150
160
170
180
190
200
210
220
-40 -25 -10 5 20 35 50 65 80 95 110 125
SUPP
LY C
URRE
NT (
µA)
TEMPERATURE (°C)
QUIESCENT CURRENTvs. TEMPERATURE
toc84
-1012345678910111213
-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5
0 100 200 300 400 500 600 700 800 900 1000
VCC
(V)
OUT
PUT
VOLT
AGE
(V)
TIME (µs)
VCCI
REFO
PWRGOOD
VCC
POWER-UP WAVEFORMS(VCC, VCCI, REFO, PWRGOOD)
toc85
-1012345678910111213
-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5
0 100 200 300 400 500 600 700 800 900 1000
VCC
(V)
OUT
PUT
VOLT
AGE
(V)
TIME (µs)
VCCIOP1OOP2OOP3OVCC
POWER-UP WAVEFORMS(VCC, VCCI, OP1O, OP2O, OP3O)
toc86
OPAMP AV = 1V/VVOP1P = 2.5VVOP2P = 1.5VVOP3P = 1.65V
-1012345678910111213
-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5
0 100 200 300 400 500 600 700 800 900 1000
VCC
(V)
OUT
PUT
VOLT
AGE
(V)
TIME (µs)
VCCI
PWMAO
COMP1O
VCC
POWER-UP WAVEFORMS(VCC, VCCI, PWMAO, COMP1O)
toc87
Maxim Integrated 21www.maximintegrated.com
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Typical Operating Characteristics (continued)
PIN # NAME DESCRIPTION1 COMP2P Comparator 2 noninverting input2 COMP1N Comparator 1 inverting input3 COMP1P Comparator 1 noninverting input4 COMP2O Comparator 2 output5 COMP1O Comparator 1 output6 VDD Comparator Output Supply Voltage. Add a 0.1µF bypass cap from VDD to GND.7 VCC Positive Supply Voltage at Internal LDO Input. Add a 1µF bypass cap from VCC to GND.8 LDOFB LDO feedback voltage. Connect to resistor divider between VCCI and GND.9 N/C Not connected
10 VCCID Digital power input. Connect this pin to VCCI.11 VCCI LDO output. Add a 0.22µF bypass cap from VCCI to GND.12 REFGND Internal reference ground. Connect to GND.13 REFO Internal reference output. 14 I/C Internally connected pin. Connect this pin to GND.15 I/C Internally connected pin. Connect this pin to GND.16 I/C Internally connected pin. Connect this pin to GND.17 OP3P Op Amp 3 noninverting input18 OP3N Op Amp 3 inverting input19 OP3O Op Amp 3 output20 OP2O Op Amp 2 output
TOP VIEW
9
11
10
12
13
14
15
16
N/C+
VCCID
VCCI
REFGND
REFO
I/C
I/C
I/C
COMP2N
PWMBP
PWMAP
PWMBO
PWMAO
SHDN
OP1O
OP1N
30
29
32
31
28
27
26
25
1 2 3 4 5 6 7 8
24 23 22 21 20 19 18 17
LDO
FB
VCC
VDD
CO
MP1
O
CO
MP2
O
CO
MP1
P
CO
MP1
N
CO
MP2
P
OP3
P
OP3
N
OP3
O
OP2
O
OP2
N
OP2
P
PWR
GO
OD
OP1
PMAX12900
EP
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
www.maximintegrated.com Maxim Integrated 22
Pin Configuration
Pin Description
Detailed DescriptionThe MAX12900 is an ultra-low-power, highly integrated 4-20mA transmitter. The MAX12900 integrates ten building blocks in a small package: a wide supply voltage range LDO, two comparators for PWM conditioning (PWMA and PWMB), two low-drift, general purpose op amps (OP1 and OP2), one zero-drift, wide-bandwidth op amp (OP3), two diagnostic comparators (COMP1 and COMP2), a power-up sequencer with power good output, and a low-drift voltage reference. There are many ways that one can connect these building blocks to optimize overall functionality and performance of the MAX12900 for a specific application.
Power-Up SequencerThe power-up sequencer keeps all op amp and PWM outputs at Hi-Z, and outputs of the comparators low during power-up until VCCI reaches 90% of its final value. After that, the PWRGOOD signal is asserted and all outputs become controlled by their inputs. The PWRGOOD signal is delayed by 0.7ms (typ) after VCCI reaches 90% of its final value, thus allowing for external loops controlled by the MAX12900 to stabilize before signaling that the part is ready.
Note that external components, such as a sensor or microcontroller, should not draw load current from VCCI until the PWRGOOD signal has been asserted.
PWM ConditionersThe PWM conditioners generate ground level when the input is below the threshold voltage, and generate VREF when the input is above the threshold voltage. The PWM conditioners can be powered down by setting the SHDN pin low. The PWM outputs are Hi-Z during shutdown.
General Purpose Op Amps (OP1, OP2)The general purpose op amps, OP1 and OP2, feature a low operating supply voltage, low input bias current, rail-to-rail outputs, and a maximized ratio of Gain Bandwidth Product (GBWP) to supply current. These CMOS devices feature ultra-low input bias current up to 15pA at 85°C. They are unity-gain stable with a 200kHz GBWP, driving capacitive loads up to 100pF. The input common mode voltage range can extend 100mV below ground with excellent common-mode rejection. The OP1 and OP2 op amps can drive the output to within 25mV of both supply rails with a 100kΩ load. Op amp settling time depends primarily on the output voltage and is slew-rate limited.The general-purpose op amps can be used as PWM filters, linear filters/amplifiers, or as linear or shunt regulator controllers, refer to the Application Information section.
PIN # NAME DESCRIPTION21 OP2N Op Amp 2 inverting input22 OP2P Op Amp 2 noninverting input23 PWRGOOD Active-high output signal that indicates when the MAX12900 is ready.24 OP1P Op Amp 1 non-inverting input25 OP1N Op Amp 1 inverting input26 OP1O Op Amp1 output
27 SHDN Active-Low, Shutdown Input for PWM Conditioners. PWM circuitry powers down and outputs go to Hi-Z state when this pin is low.
28 PWMAO PWM conditioner output A29 PWMBO PWM conditioner output B30 PWMAP PWM conditioner input A31 PWMBP PWM conditioner input B32 COMP2N Comparator 2 inverting inputEP GND Exposed pad, chip ground.
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Pin Description (continued)
Zero-Drift High Bandwidth Op Amp (OP3)The zero-drift, wide bandwidth op amp OP3 uses an innovative auto-zero technique that allows precision and low noise with a minimum amount of power. The ultra-low input offset voltage, offset drift, and 1/f noise allow for building a highly accurate current transmitter. The high GBWP allows for noise suppression over a wider frequency band. The OP3 amplifier achieves rail-to-rail performance at the output. Driving large capacitive loads can cause instability in many op amps. The OP3 amplifier is stable with capacitive loads up to 300pF. Stability with higher capacitive loads can be improved by adding an isolation resistor in series with the op amp output.
Low-Drift 2.5V Voltage ReferenceThe precision bandgap reference uses a proprietary curvature-correction circuit and laser-trimmed thin-film resistors, resulting in a low temperature coefficient of <10ppm/°C, and initial accuracy of better than 0.2%. The reference can sink and source up to 500µA, making it attractive for use in low-voltage applications. It is stable for capacitive loads up to 2nF. In applications where the load can experience step changes, an output capacitor will reduce the amount of overshoot (or undershoot) and assist the circuit’s transient response. The reference typically turns on and settles to within 0.1% of its final value in 220µs.
General-Purpose ComparatorsThe comparators COMP1 and COMP2 feature a 2µs propagation delay. Two independent rails supply each comparator. The input stage operates with VCCI from 3.0V to 5.5V, and the output drivers operate with VDD from 1.8V to 3.6V. This allows for a direct connection to a microcontroller. The internal output driver allows for rail-to-rail output swings with up to 100µA load. Both comparators offer a push-pull output that sinks and sources current.
The input common-mode voltage range for these devices extends from 0V to VCCI - 1.3V. The MAX12900’s com-parators can operate at any differential input voltage with-in these limits. Input bias current is typically less than 1nA. These comparators can be used for VCC, VDD or VREF voltage monitoring or other diagnostic functions, providing status information to the microcontroller.
LDOAll components of the MAX12900 are powered from an integrated LDO that generates a 3.0V to 5.5V VCCI volt-age from an input VCC voltage of 4.0V to 36V. The LDO provides a clean supply for sensitive analog circuitry. The output of the LDO is set by external resistors and can be selected using the following equation:
( )OUTV 1.212V 1 R1/R2= × +
Where, 1.212V is an internal reference voltage, R1 and R2 form a resistor divider providing feedback voltage to close the LDO loop, refer to the typical application diagrams. It is recommended that R2 be less than or equal to 470kΩ. For example, for VCCI = 3.3V, R1 = 698k and R2 = 402k can be used from standard 1% E96 resistor series values.
Application InformationLoop-Powered 4-20mA Sensor Transmitter with PWM inputsOne of the possible implementations of a loop powered 4-20mA sensor transmitter is shown in Figure 2. In this application diagram, the PWM inputs from a microcontroller are reshaped by the conditioners, filtered by the OP1 op amp and converted to an analog voltage. The voltage is then converted to a 4-20mA loop current by OP3, an external transistor Q1 and a current sense resistor RSENSE.
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Figure 2. Loop-Powered 4-20mA Transmitter with Two PWM Inputs
MAX12900VCCID PWRGOOD VD D
SHDN
REFO
OP1P
OP1N
OP1O
OP3P
OP3NOP3O
OP2P
OP2NOP2O
PWM BOPWMBP
PWMAOPWMAP
PWM11.5k
22.6k
OP1
294k
OP2
OP3
TO MICROCONTROLLER
1M4.99k
24.9k
24.9k
100k
R EFO/2
LDO
R1
R2
LDOFB
VCC
VCCI
COMP2NCOM P2O
COMP2P
COMP1N
COMP1PCOM P1O
VCCI
VCC
100
511k
FSK_OUT
POWER-UPSEQUENCER
REFGN DEP
4-20mA LOOP
2.5VREF
R3 22.6k
R4 1.5M
R6
R5
R9
294kR10
R8
100kR7
24.9
R11
R12
R13R16
RSENSE
402k
R14
R15
R17D1
Q1
C6
C1
C2
C3
C4
C5
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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The component selection of this circuit is as follows.Let us assume the loop current range is 2.5mA to 27.5mA including NAMUR burnout detection. With the 24.9Ω RSENSE resistor and the 2.5mA to 27.5mA loop current range, the non-inverting input of OP3 (OP3P) should be in the range 62.25mV (2.5mA x 24.9Ω = 62.25mV) to 684.75mV (27.5mA x 24.9Ω = 684.75mV).The loop current (Iloop) has two components: offset current generated by the reference output (Ioffset) and PWM signals converted to current (IPWMA, IPWMB).
Iloop = Ioffset + IPWMA + IPWMBAfter power-up, assuming the PWM signals do not contribute to the loop current, the initial 2.5mA offset current is generated by the reference voltage as follows:
×=
× SENSE
REFO R13IoffsetR8 R
The PWM currents are given by
× × × =×
× × × =×
PWMASENSE
PWMBSENSE
R5PWMADC REFO R13R3I
R7 R
R5PWMBDC REFO R13R4I
R7 R
where, PWMADC and PWMBDC are the PWM duty cycles.
DAC Implementation with PWM and Low-Pass FilterThe sensor data received from the microcontroller can be arranged into a coarse and a fine PWM signal.Both the coarse and fine signals can have up to 8 bits of resolution. The PWM signals are then converted to their voltage level representations via a LPF. The PWM outputs from the MAX12900 connect to the LPF through two gain setting resistors with ratios up to 1:256; the voltage levels at the output of the LPF are proportional to the PWM duty cycles.The application diagram in Figure 2 shows an implementation of a 14-bit resolution signal path. The PWMAP input receives the coarse signal with 8-bits of resolution, and the PWMBP input receives the fine signal with 6-bits of resolution. A 1:66 ratio is used for the two gain setting resistors.The coarse gain is set to 1 by using a 22.6kΩ gain resistor R3 and a 22.6kΩ feedback resistor R5, while the fine gain is set to 1/66 by using a 1.5MΩ gain resistor R4. The two PWM outputs are summed via the 22.6kΩ feedback resistor R5 of OP1.The PWM frequency and filter parameters must satisfy the 4–20mA current loop noise requirements. In this example, the PWM frequency is 10kHz and the 4–20mA transmitter is designed to meet the HART specification. Consequently, the broadband noise of the current loop during silence must be below 138mVRMS, and the in-band noise (500Hz–10kHz) must be below 2.2mVRMS across a 500Ω loop load. In order to reduce the noise level to 2.2mVRMS in-band, the LPF should suppress the noise by more than 60dB (2.5V/2.2mV = 1136.4 or 61dB). Therefore, the cut-off frequency of the LPF should be less than 70Hz with a 40dB/decade roll-off slope. OP1 implements a second-order multi-feedback LPF.
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Voltage-Controlled Current SourceThe integrated OP3 op amp can be combined with an external current modulating transistor Q1 to implement a precision voltage controlled current source. Q1 can be either an N-MOSFET or a bipolar NPN transistor and needs to satisfy the peak voltage and power dissipation criteria of the current loop. OP3 and Q1, in combination with a few external components, provide an optimal point to compensate the current loop.
Loop Current DiagnosticIn the application example of Figure 2, the second general purpose amplifier (OP2) is used for current diagnostics and provides feedback to the microcontroller.
Connection with a SensorThe MAX12900 can work with any kind of sensor trans-mitter, even though it is designed with smart sensors in mind. A smart sensor means that it has an integrated microcontroller and the ability to provide either linear analog or PWM output. If the total current consumption of the transmitter is less than 4mA, power to the sensor and the digital VDD supply can be provided directly from the VCCI pin. If the transmitter requires more than 4mA, an external dc-dc switching converter can be used. Such
a scenario is shown in the application circuit in Figure 3, where OP2 is utilized as a linear voltage regulator and the dc-dc converter powers the microcontroller and drives the VDD supply pin.
Loop Powered 4-20mA Transmitter for Explosion-Proof DevicesIf the sensor is to be deployed in hazardous or explosive areas, it must use additional protective components to limit the electrical energy from short circuit or failure conditions, and to prevent sparks that could cause an explosive atmosphere to ignite.Figure 4 shows an application circuit with improved protection in hazardous environments. In order to limit the electrical energy that goes to the sensor transmitter, an additional Q2 transistor and Zener diodes are added. Typically, a Zener diode should have a clamping voltage from 5V to 12V. In this case, both Q1 and Q2 transistors are the current modulating elements of the circuit. The total 4-20mA loop current is the sum of the current flowing through the Zener diodes, the Q1 transistor and the sensor. Each current path is protected by limiting resistors. Most of the power dissipation is spread out through Q1, Q2 and the Zener diodes, which makes the system design more robust.
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Figure 3. Loop-Powered 4-20mA Transmitter with an External Voltage Regulator
MAX12900
SHDN
REFO
OP1P
OP1N
OP1O
OP3P
OP3NOP3O
OP2P
OP2NOP2O
PWMBOPWMBP
PWMAOPWMAP
PWM11.5k
22.6k
OP1
294k
OP2
OP31M4.99k
24.9k
24.9k
REFO/2
LDO
R1
R2
LDOFB
VCCVCCI
COMP2NCOMP2O
COMP2P
COMP1N
COMP1PCOMP1O
VCCI
VCC
511k
FSK_OUT
4-20mA LOOP
2.5VREF
R3 22.6k
R4 1.5M
R6
R5
R9
294kR10
R8
100kR7
24.9
R11
R12
R13R16
RSENSE
100R14
R15
R17
REFO
OPTIONALDC/DC
TO SENS OR/MICROCONTROLLER
VCCI
RLIM
D1
C1
C2
C3
C4
C5
C6
C7
Q1
Q2
Q3
VDD
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
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Figure 4. Loop-Powered 4-20mA Transmitter for Hazardous Environments
MAX12900
SHDN
REFO
OP1P
OP1N
OP1O
OP3P
OP3NOP3O
PWMBOPWMBP
PWMAOPWMAP
PWM11.5k
22.6k
OP1
294k OP31M4.99k
24.9k
24.9k
REFO/2
LDO
R1
R2
LDOFB
VCCVCCI
COMP2NCOMP2O
COMP2P
COMP1N
COMP1PCOMP1O
VCCI
VCC
511k
FSK_OUT
4-20mA LOOP
2.5VREF
R3 22.6k
R4 1.5M
R6
R5
R9
294kR10
R8
100kR7
24.9
R11
R12
R13R16
RSENSE
100
RLIM
R17
TO SENS OR /MICROCONTROLLER
VCCI
12V
OP2P
OP2NOP2OOP2 TO MICROCONTROLLER
100k
402k
R14
R15
R18
R19
C1
C2
C3
C4
C5
D1 D2 D3
C6
Q2
Q1
D4 D5 D6
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
www.maximintegrated.com Maxim Integrated 29
+ Denotes a lead(Pb)-free/RoHS-compliant package.T = Tape and Reel
PART PACKAGE BODY SIZE PIN PITCH TEMP RANGE (°C)MAX12900AATJ+ TQFN32 5mm x 5mm 0.5mm -40 to +125
MAX12900AATJ+T TQFN32 5mm x 5mm 0.5mm -40 to +125
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
www.maximintegrated.com Maxim Integrated 30
Ordering Information
Chip InformationPROCESS: BiCMOS
REVISIONNUMBER
REVISIONDATE DESCRIPTION PAGES
CHANGED0 9/17 Initial release —1 10/17 Updated title of data sheet 1–302 3/18 Updated Equation 3 26
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2018 Maxim Integrated Products, Inc. 31
MAX12900 Ultra-Low-Power 4-20mA Sensor Transmitter
Revision History
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
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