VITESSE VSC7810X, VSC7810WC, VSC7810WD, VSC7810WB Datasheet

VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC7810

Photodetector/Transimpedance Amplifier

Family for Optical Communication

G52145-0, Rev 4.1 Page 1 04/05/01

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Features

General Description

The VSC7810 integrated Photodetector/Transimpedance Amplifier provides a highly integrated solution for converting light from a fiber optic communications channel into a differential output voltage. The benefits of V itesse S emiconduct or’ s Galliu m Arsenide H-GaAs pr ocess are f ully ut ilized t o provid e very high bandwi dth and low noise in a product with a large optically active area for easy alignment. The sensitivity, duty cycle distortion and jitter meet or exceed all Fibre Channel and Gigabit Ethernet application requirements. Par ts are available in either die form, flat-windowed packages or in ball-l ens packag es.

By using a metal-semiconductor-metal (MSM) photodetector with a monolithic integrated transimpedance amplifier , the input capacitance is lowered which allows for a la rger optically active area than in discrete photodetectors. Integration also allows superior tracking over process, temperature and voltage between the photodetector and the amplifier, resulting in higher performance. This part can easily be used in developing Fibre Channel Electro-Optic Receivers which exhibit very high performance and ease of use.

VSC7810 Block Diagram

Part Number Data Rate

Bandwidth

(MHz)

Input Noise

(

µW rms)

Optically Active Area

(

µm diameter)

VSC7810 Full Speed: 1.25Gb/s 1200 0.45 100

• Integrated Photodetector/Transimpedance

Amplifier Optimized for High-Speed Optical Communications Applications

• Integrated AGC

• Fibre Channel/Gigabit Ethernet Compatible

• High Bandwidth

• Low Input Noise Equivalent Power

• Large Optically Active Area

• Single 5V Power Supply

Both DOUTP and DOUTN are back-terminated to 25Ω.

Photodetector/Transimpedance Amplifier

DOUTP

DOUTN

+3.3V

GND

VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC7810

Photodetector/Transimpedance Amplifier Family for Optical Communication

Page 2 G52145-0, Rev 4.1

04/05/01

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Table 1: Electro-Optical Specifications

(1)

Notes: (1) Specified over 0°C (ambient) to 70°C (case). (2) Typical conditions 25°C and 3.3V power supply. (3) See Note 1 in

Application Note 48. (4) P = Incident Optical Power (5) See Note 2 in Application Note 48.

Symbol Parameter Min Typ

(2)

Max Units Conditions

V

SS

Supply Voltage 4.5 5.0 5.5 V

I

DD

Supply Current 13 26 40 mA

PSRR Power Supply Rejection Ratio 35 - - dB

Frequencies up to 40MHz (includes external filter).

λ Wavelength 700 840 850 nm f

C

Low Frequency Cutoff - - 1.8 MHz -3dB, P = -15dBm @ 50MHz

(4)

BW Optical Modulation Bandwidth 800 1200 1300 MHz -3dB, P = -15dB m @ 50MHz

(4)

S Sensitivity -22 -25 -27 dBm 1.063Gb/s, BER10

-12(3)

R

O

Single-Ended Output Impedance 25 - 60 Ω

V

D

Differential Output Voltage 0.35 0.52 0.65 V

P = -4.5dBm, R

LOAD

= 100Ω differenti a l

R

D

Differential Responsivity 0.8 2.2 - mV/µW

R

LOAD

= 100Ω

P = -15dBm @ 50MHz

V

DC

Output Bias Voltage 1.2 1.5 2.5 V

∆V

DC

Bias Offset Voltage - 40 150 mV

NEP

O

Input Noise Equivalent Power 0.35 0.45 0.93 µW rms P = 0mW

(5)

V

NO

Output Noise Volta ge 0.55 0.66 0.75 mV rms P = 0mW

(5)

DCD Duty Cycle Distortion - 1.5 4.5 % P = -4.5dBm I

OUT

Output Drive Current 2.5 - 8 mA

PDJ Pattern Dependent Jitter 20 40 60 ps

P = -4.5dBm +/-10% Voltage Window

Optically Active Area - 100 - µm Diameter

PPJ PP Jitter 120 160 200 ps P = -5dBm t

R

Rise Time 310 355 400 ps 20%-80% P = -4.5dBm

t

F

Fall Time 280 325 370 ps 20%-80% P = -4.5dBm

VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC7810

Photodetector/Transimpedance Amplifier

Family for Optical Communication

G52145-0, Rev 4.1 Page 3 04/05/01

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Figure 1: Amplifude vs. Frequency

Table 2: Absolute Maximum Ratings

Table 3: Recommended Operating Conditions

NOTE: (1) See Note 1 i n "Notes on M easurement Condi tions & Appl ications" se ction of thi s data sheet for extende d temperature range

operation.

Symbol Parameter Limits

V

SS

Power Supply 6V

T

STG

Storage Temperature -55°C to 125°C (case temp erat ure under bias)

H

STG

Storage Humidity 5 to 95% R.H. (includi ng con de n sa ti on)

H

OP

Operating Humidity 8 to 80% R.H. (excluding condensation)

P

INC

Incident Optical Power +3dBm

IS Impact Shock

500 G. Half Sine Wave Pulse Duration 1 +/-0.5 ms 3 blows in each direction

V

IB

Vibration

20 > 2000 > 20 Hz, 10 Minutes 10 G. Peak Acceleration 4 Complete Cycles, 3 Perpendicular Axes

V

ESD

ESD Voltage on DOUTP, DOUTN, VSS, GND

1500V

Symbol Parameter Limits

V

SS

Power Supply 4.5V to 5.5V (5V nominal)

T

OP

Operating Temperature 0°C (ambient) to 70° C (case) normal range and 90°C (case) extended range

(1)

1 096.795 514 MHz

1 000.150

1 999.700

21

3

Amplitude

Frequency (MHz)

Frequency response of VSC7810WB upper 3db frequency is measured with respect to response at 50 MHz

VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC7810

Photodetector/Transimpedance Amplifier

Family for Optical Communication

Page 4 G52145-0, Rev 4.1

04/05/01

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Table 4: Pin Table Specifications for Ball Lens Packages, Flat Window Packages and Bare Die

Note: Pin Diagram is identical for both TO-46 and TO-56 package styles.

Figure 2: Pin Diagram

Figure 3: Schematic View of Bare Die Pad Assignments

Symbol Description

DOUTP Data output normal (with reference to incident light) DOUTN Data output complement (inverting, with reference to incident light)

VSS Power supply

GND Ground (package case)

DOUTP

DOUTN

GND

VSS

Bottom View

DOUTN

GND

VSS

DOUTP

VITESSE

SEMICONDUCTOR CORPORATION

Data Sheet

VSC7810

Photodetector/Transimpedance Amplifier

Family for Optical Communication

G52145-0, Rev 4.1 Page 5 04/05/01

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Temperature Dependence of Operating Parameters

This section describes the dependence of important operating parameters shown in Table 1 as a function of die (or equivalently junction) tempeature and power supply. In order to relate the die temperature to an equivalent case temperature, the following thermal characteristics of the package are provided (note th at the therma l conductivity is identical for TO-46 and TO-56 package styles.

Table 5: Thermal Resistance Calculation for TO-56 and TO-46 Packages

Chip Size 0.168cm x 0.104cm Thermal Path Chip Area A 0.015cm

2

Die Height (T

DIE

)0.066cm

Epoxy Thickness (T

EPOXY

) 0.0076cm

Header Thickness (T

HEADER

)

(Average for TO-46 and TO-56 package)

0.115cm

Thermal Conductivities K GaAs 0.55W/cm °C K epoxy 0.0186W/cm °C K kovar 0.17W/cm °C

θ

GaAs

K

GaAs

A

T

die

0.066

0.55 x 0.015

= 8 °C/W==

θ

epoxy

K

epoxy

A

T

epoxy

0.0076

0.0186 x 0.015

= 27.24 °C/W==

θ

kovar

K

kovar

A

T

kovar

0.12

0.17 x 0.015

= 47 °C/W==

θ

JC

= Thermal Resistance from Junction to Case = (8 + 27.24 + 47) = 82.24 °C/W

Example:

For VSC7810 at nominal supply current of 25mA and Vss = 5V Temperature rise from junction to case = 0.025A x 5V x 82.24 °C/W = 10.28 °C

T

J

θ

GaAs

θ

EXPOXY

θ

KOVAR

T

C