wireless power receiver and 400ma buck battery this technique modulates the resonant frequency of a

Download Wireless Power Receiver and 400mA Buck Battery This technique modulates the resonant frequency of a

Post on 11-Mar-2020

0 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • LTC4120

    1 4120fa

    For more information www.linear.com/LTC4120

    Typical applicaTion

    FeaTures DescripTion

    Wireless Power Receiver and 400mA Buck Battery Charger

    The LTC®4120 is a constant-current/constant-voltage wireless receiver and battery charger. An external program- ming resistor sets the charge current up to 400mA. The programmable float voltage of the LTC4120 accommodates several battery chemistries. The LTC4120 uses a Dynamic Harmonization Control (DHC) technique that allows high efficiency contactless charging across an air gap.

    The LTC4120 regulates its input voltage via the DHC pin. This technique modulates the resonant frequency of a receiver tank to automatically adjust the power received as well as the power transmitted to provide an efficient solution for wirelessly charging battery-powered devices.

    Wireless charging with the LTC4120 provides a method to power devices in harsh environments without requiring expensive failure-prone connectors. This allows products to be charged while locked within sealed enclosures, or in moving or rotating equipment, or where cleanliness or sanitation is critical.

    This full featured battery charger includes accurate RUN pin threshold, low voltage battery preconditioning and bad battery fault detection, timer termination, auto-recharge, and NTC temperature qualified charging. The FAULT pin provides an indication of bad battery or temperature faults.

    Once charging is terminated, the LTC4120 signals end-of- charge via the CHRG pin, and enters a low current sleep mode. An auto-restart feature starts a new charging cycle if the battery voltage drops by 2.5%.

    applicaTions

    n Dynamic Harmonization Control Optimizes Wireless Charging Over a Wide Coupling Range

    n Wide Input Voltage Range: 4.3V to 40V n Adjustable Battery Float Voltage: 3.5V to 11V n 50mA to 400mA Charge Current Programmed with a

    Single Resistor n ±1% Feedback Voltage Accuracy n Programmable 5% Accurate Charge Current n No Microprocessor Required n No Transformer Core n Thermally Enhanced, Low Profile 16-Lead

    (3mm × 3mm × 0.75mm) QFN Package

    n Handheld Instruments n Industrial/Military Sensors and Devices n Harsh Environments n Portable Medical Devices n Physically Small Devices n Electrically Isolated Devices L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

    +

    INTVCCIN FREQRUN

    BOOST

    SW

    CHGSNS

    NTC

    DHC

    FAULT

    CHRG

    3.01k 10µF

    T

    4120 TA01a

    Li-Ion 4.2V

    22nF

    26.7nF

    6.5nF

    47µH5µH

    Tx CIRCUITRY

    10µF

    2.2µF

    33µH

    FB

    PROG FBG

    LTC4120

    GND

    BAT

    1.01M

    1.35M

    Wireless Rx Voltage/Charge Current vs Spacing

    SPACING (cm) 0.4

    V I N(

    RX ) (

    V)

    CHARGE CURRENT (m A)

    30

    35

    40

    1.0 1.4

    4120 TA01b

    25

    20

    0.6 0.8 1.2 1.6 1.8

    VIN

    15

    10

    200

    267

    333

    400

    133

    67

    0

    ICHARGE MAX

    NOT CHARGING

    CHARGING

    http://www.linear.com/LTC4120 http://www.linear.com/LTC4120

  • LTC4120

    2 4120fa

    For more information www.linear.com/LTC4120

    pin conFiguraTionabsoluTe MaxiMuM raTings

    IN, RUN, CHRG, FAULT, DHC ...................... –0.3V to 43V BOOST ................................... VSW – 0.3V to (VSW + 6V) SW (DC) ........................................ –0.3V to (VIN + 0.3V) SW (Pulsed

  • LTC4120

    3 4120fa

    For more information www.linear.com/LTC4120

    elecTrical characTerisTics The l denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = VRUN = 15V, VCHGSNS = VBAT = 4V, RPROG = 3.01k, VFB = 2.29V. Current into a pin is positive out of the pin is negative.

    SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

    VIN Operating Input Supply Range l 4.3 40 V

    VBAT Battery Voltage Range 0 11 V

    IIN DC Supply Current Switching, FREQ = GND 3.5 mA

    Standby Mode (Note 3) l 130 220 µA

    Sleep Mode (Note 3) VFB = 2.51V (Note 3)

    l

    60

    100

    µA

    Disabled Mode (Note 3) l 37 70 µA

    Shutdown Mode (Note 3) l 20 40 µA

    ∆VDUVLO Differential Undervoltage Lockout VIN-VBAT Falling, VIN = 5V l 25 80 160 mV

    Hysteresis VIN-VBAT Rising, VIN = 5V l 80 115 175 mV

    UVINTVCC INTVCC Undervoltage Lockout INTVCC Rising, VIN = INTVCC + 100mV, VBAT = NC l 4.00 4.15 4.26 V

    Hysteresis INTVCC Falling 220 mV

    VINTVCC INTVCC Regulated Voltage l 4.14 4.24 4.29 V

    ∆INTVCC INTVCC Load Regulation IINTVCC = 0mA to –5mA (Note 4) 1.7 %

    Battery Charger

    IBAT BAT Standby Current Standby Mode (Notes 3, 7, 8) l 2.5 4.5 µA

    BAT Shutdown Current Shutdown Mode (Notes 3, 7, 8) l 1100 2000 nA

    IFB Feedback Pin Bias Current (LTC4120) VFB = 2.5V (Note 7) l 15 50 nA

    IFBG(LEAK) Feedback Ground Leakage Current Shutdown Mode (Notes 3, 7) l 1 µA

    RFBG Feedback Ground Return Resistance l 1000 2000 Ω

    VFB(REG) Feedback Regulation Voltage (Note 5) l

    2.393 2.370

    2.400 2.407 2.418

    V V

    ICHG Battery Charge Current RPROG = 3.01k RPROG = 24.3k

    l

    l

    383 45

    401 50

    421 55

    mA mA

    VUVCL Undervoltage Current Limit VIN Falling 12.0 V

    VRCHG Battery Recharge Threshold VFB Falling Relative to VFB_REG l –42 –52 –62 mV

    hPROG Ratio of BAT Current to PROG Current 988 mA/mA

    VPROG PROG Pin Servo Voltage l 1.210 1.222 1.245 V

    RSNS CHGSNS-BAT Sense Resistor IBAT = –100mA 300 mΩ

    ILOWBAT Low Battery Linear Charge Current 0V < VFB < VTRKL, VBAT = 2.6V 6 10 16 mA

    VLOWBAT Low Battery Threshold Voltage VBAT Rising Hysteresis

    l 2.15 2.21 143

    2.28 V mV

    ITRKL Switch Mode Trickle Charge Current VFB < VTRKL, VBAT > VLOWBAT ICHG/10 mA

    VPROG(TRKL) PROG Pin Servo Voltage in Switch Mode Trickle Charge

    VBAT > VLOWBAT, 1.22V < VTRKL 120 mV

    VTRKL Trickle Charge Threshold VFB Rising (Note 5) l 1.66 1.68 1.70 V

    Hysteresis VFB Falling (Note 5) 45 mV

    hC/10 End of Charge Indication Current Ratio (Note 6) 0.1 mA/mA

    Timer Safety Timer Termination Period l 1.3 2.0 2.8 Hours

    Bad Battery Termination Timeout l 19 30 42 Minutes

    http://www.linear.com/LTC4120

  • LTC4120

    4 4120fa

    For more information www.linear.com/LTC4120

    elecTrical characTerisTics The l denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = VRUN = 15V, VCHGSNS = VBAT = 4V, RPROG = 3.01k, VFB = 2.29V. Current into a pin is positive out of the pin is negative.

    SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

    Switcher

    fOSC Switching Frequency FREQ = INTVCC FREQ = GND

    l

    l

    1.10 0.56

    1.35 0.71

    1.75 0.81

    MHz MHz

    tMIN(ON) Minimum Controllable On-Time (Note 9) 120 ns

    DC Duty Cycle Maximum (Note 9) l 94 %

    RDS(ON)TOP Top Switch RDS(ON) ISW = –100mA 0.7 Ω

    RDS(ON)BOT Bottom Switch RDS(ON) ISW = 100mA 0.35 Ω

    IPEAK Peak Current Limit Measured Across RSNS with a 15µH Inductor in Series with RSNS (Note 9)

    585 750 1250 mA

    ISW Switch Pin Current (Note 8) VIN = Float, VRUN = 0V, VSW = 8.4V l 15 30 µA

    Status Pins FAULT, CHRG

    VOL Pin Output Voltage Low I = 2mA 500 mV

    ILEAK Pin Leakage Current V = 45V, Pin High Impedance 0 1 µA

    NTC

    VTOO_COLD Cold Temperature VNTC/VINTVCC Fault Rising VNTC Threshold Falling VNTC Threshold

    l 73 74 72

    75 %INTVCC %INTVCC

    VTOO_HOT Hot Temperature VNTC/VINTVCC Fault Falling VNTC Threshold Rising VNTC Threshold

    l 35.5 36.5 37.5

    37.5 %INTVCC %INTVCC

    VDIS NTC Disable Voltage Falling VNTC Threshold Rising VNTC Threshold

    l 1 2 3

    3 %INTVCC %INTVCC

    INTC NTC Input Leakage Current VNTC = VINTVCC –50 50 nA

    RUN

    VEN Enable threshold VRUN Rising l 2.35 2.45 2.55 V

    Hysteresis VRUN Falling 200 mV

    IRUN Run Pin Input Current VRUN = 40V 0.01 0.1 µA

    VSD Shutdown Threshold (Note 3) VRUN Falling l 0.4 1.2 V

    Hysteresis 220 mV

    FREQ

    VIL FREQ Pin Input Low l 0.4 V

    VIH FREQ Pin Input High VINTVCC-VFREQ l 0.6 V

    IFREQ FREQ Pin Input Current 0V < VFREQ < VINTVCC ±1 µA

    Dynamic Harmonization Control

    VIN(DHC) Input Regulation Voltage 14 V

    IDHC DHC Pin Current VDHC = 1V, VIN < VIN(DHC) 330 mARMS

    Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC4120 is tested under pulsed load conditions such that TJ ≈ TA. The LTC4120E is guaranteed to meet performance specifications for junction temperatures from 0°C to 85°C. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LTC4120I is guaranteed over the full –40°C to 125

Recommended

View more >