8/6/2019 453-02384-0-CXA1685M

1/8

High-Speed Transimpedance Amplifier

Description

CXA1685M is a low noise transimpedance

amplifier, particularly suitable for fiber-optic system.

CXA1685M is fabricated using high-speed bipolar

process.

Features

High transimpedance: Q 11.2k (Typ.)

Q 10.8k (Typ.)

Wide band width (3dB): Q 177MHz (Typ.)

Q 157MHz (Typ.)

Maximum input current: 1mA

Low noise: 1.7pA/ Hz (Typ.)

Applications

SONET/SDH: 155Mb/s

Fiber channel:133Mb/s

FDDI: 125Mb/s

Absolute Maximum Ratings

Supply voltage VCC VEE 0.3 to +7.0 V

Minimum input voltage VIN VEE V Input current IIN 1 to +1 mA

Output current

(Q/Q) (Continuous) IO 0 to 50 mA

(Surge) 0 to 100 mA

Storage temperature Tstg 65 to +150 C

Recommended Operating Conditions

DC power supply voltage

VCC VEE 4.75 to 5.46 V

Operating ambient temperatureTa 0 to +85 C

Structure

Bipolar silicon monolithic IC

1 E94X22A8Y

Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by

any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the

operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.

CXA1685M

8 pin SOP (Plastic)

8/6/2019 453-02384-0-CXA1685M

2/8

2

CXA1685M

Block Diagram and Pin Assignment

AC Electrical Characteristics (VCC = VCCA = GND, VEES = VEEDA = 5.46 to 4.75V, Ta = 0 to +85C)

Item Symbol Test Condition Min. Typ. Max. Unit.

Bandwidth(3dB)

Input Current Noise SpectralDensity (Mean value)

Q

Q

f3dBQ

f3dBQ1

In fN = 1kHZ to 156MHZ

113

109

177

157

1.7

MHZ

pA/ HZ

1 Assumes photodiode capacitance; CPD < 1.0pF, output load capacitance; Cout = 2.0pF,

output load resistor; Q: 620 to VEE, Q: 1.3k to VEE

45

7

8 1

2

36

ZT VCCAVCC

QIN

QC

VEEDAVEES

Electrical Characteristics

DC Electrical Characteristics (VCC = VCCA = GND, VEES = VEEDA = 5.46 to 4.75V, Ta = 0 to +85C)

Item Symbol Test Condition Min. Max.Typ. Unit

Supply current

Transimpedance

Max. Input Current before clipping

Max. Input Current

Bias votlage

IEE

ZTQ

ZTQ

IIN

IIN2

VIN

VQ

VQ

VC

CIN

input pin left open

Q

Q

IN

Q

Q

C

input pin left open

15.3

6.6

6.2

+40

+1000

10.0

11.2

10.8

VEE + 2.5

VEE + 1.7

VCC 2.4

VEE + 1.7

1.3

14.8

14.3

Ta = 25C

Input capacitance

mA

k

A

V

pF

8/6/2019 453-02384-0-CXA1685M

3/8

3

CXA1685M

Application Circuit

Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility forany problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.

Cautions for Handling

1. As the electronic breakdown level is weak, take care to handle.

2. The internal resistor of the output pin does not have the capability of drive (RL = 10k). The terminal

resistors must be connected. The resistance value is shown in application circuit.

VCCAVCC

IN

QC

VEEDAVEES

45

7

8 1

2

36

ZT

Q

VCC

VEE

1.0F

0.1F 0.1F

620 1.3k

PD

QQ

8/6/2019 453-02384-0-CXA1685M

4/8

4

CXA1685M

Typical Performance

Typical frequency characteristics (VCC VEE = 5.0V, Ta = 25C)

Typical Output Wave forms (VCC VEE = 5.0V, Ta = 25C)

f3dB = 157MHzQ Output 5dB/div

0 500M 1.0G

65.9000ns 90.9000ns 115.900ns

VIN = 36dBm, fIN = 80MHz20mV/div

Q

Q

Duty Cycle Distortion vs Input Current

f3dB = 177MHzQ Output 5dB/div

0 500M 1.0G

Q Output fIN = 155Mbps55

50

45

40

35

300 200 400 600 800 1000

IIN [A]

QOutputDCD[%]

Q Output

IIN [A]

fIN = 155Mbps55

50

45

40

35

300 200 400 600 800 1000

QOutputDCD[%]

8/6/2019 453-02384-0-CXA1685M

5/8

5

CXA1685M

VQ vs IIN

140

150

160

170

180

190

200

f3dBQ vs VEE

Ta = 40CTa = 25CTa = 85C

140

150

160

170

180

190

200

f3dBQ vs Ta

VCC VEE = 5.0VVCC VEE = 5.5V

140

150

160

170

180

190

200

f3dBQ vs Ta

VCC VEE = 4.7VVCC VEE = 5.0VVCC VEE = 5.5V

140

150

160

170

180

190

200

f3dBQ vs VCCVEE

Ta = 40CTa = 25CTa = 85C

f3dB[MHz]

f3dB[MHz]

VQ[

V]

4.5

1

1.5

2

2.5

3

3.5

4

VQ vs IIN

Ta = 85CTa = 25CTa = 40C

f3dB[MHz]

f3dB[MHz]

4.5

1

1.5

2

2.5

3

3.5

4

4.6

VEE [V]

5.6 5.4 5.2 5.0 4.8 100

Ta [C]

50 25 0 25 50 75

100

Ta [C]

50 25 0 25 50 754.6

VEE [V]

5.6 5.4 5.2 5.0 4.8

IIN [A]

0 20050 100 150 200

IIN [A]

0 50 100 150

Ta = 85CTa = 27CTa = 40C

VCC VEE = 4.7V

VQ[

V]

8/6/2019 453-02384-0-CXA1685M

6/8

6

CXA1685M

100

100

4.610.2

8.8

10

9.8

9.6

9.4

9.2

9

IEE vs VEE

VEE [V]

5.6 5.4 5.2 5 4.8

Ta = 25C

VEE [V]

4

3

3.8

3.6

3.4

3.2

VQ vs VEE

5.6 5.4 5.2 5 4.8

Ta = 25C

4.6

IEE

[mA]

VQ[

V]

4.63

1.8

2.8

2.6

2.4

2

VQ vs VEE

VEE [V]

5.6 5.4 5.2 5 4.8

Ta = 25C

2.2

100

Ta [C]

VQ vs Ta

50 25 25 50 75

VEE = 5.0V

0

Ta [C]

10.2

8.8

10

9.8

9.6

9.4

9.2

9

IEE vs Ta

50 25 25 50 75

VEE = 5.0V

0

504

3

3.8

3.6

3.4

3.2

VQ vs Ta

Ta [C]

25 25 50 75

VEE = 5.0V

0

3

1.8

2.8

2.6

2.4

2

IEE

[mA]

2.2

VQ[

V]

VQ[V

]

VQ[V

]

8/6/2019 453-02384-0-CXA1685M

7/8

7

CXA1685M

Test Circuit (Ta = 25C, VEE = 5.0V)

40dB

ATT 1001

2p

1.3k 2p

510.1

510.1

2p620

50

50

Signal Generator

Tracking Generator

Spectrum Analyzer/Oscilloscope

51

680p

VEE

VEE

VEE VEE

VEEVEE

8/6/2019 453-02384-0-CXA1685M

8/8

8

CXA1685M

PACKAGE STRUCTURE

PACKAGE MATERIAL

LEAD TREATMENT

LEAD MATERIAL

PACKAGE MASS

EPOXY RESIN

SOLDER/PALLADIUM

42/COPPER ALLOY

0.1g

SOP-8P-L03

SOP008-P-0225

8PIN SOP (PLASTIC)

SONY CODE

EIAJ CODE

JEDEC CODE

0to 10

0.1 0.1+ 0.15

0.5

0.2

DETAILA

8 5

1 4

4.4

0.1

+0.3

1.27

1.25 0.15+ 0.4

6.4

0.4

A

5.0 0.1

+ 0.4

0.10

PLATING

M0.24b

B

(0.1

5)

0.1

5

0.0

5

(0.4)

b = 0.4 0.05

DETAIL B : SOLDER

0.1

5

0.0

1b = 0.4 0.03

DETAIL B : PALLADIUM

+0.0

3+ 0.1

+0.1

NOTE : PALLADIUM PLATINGThis product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).

Package Outline Unit: mm