Datasheet VSC7711X Datasheet (VITESSE)

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VITESSE SEMICONDUCTOR CORPORATION

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10/6/99 741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

VITESSE

SEMICONDUCTOR CORPORATION

dvance Product Information

SC7711

Transimpedance Amplifier

Family for Optical Communication

G52178-0, Rev. 2.1

Features

• Transimpedance Amplifier optimized for
high speed optical communications applications

• Integrated AGC

• Fibre Channel and Gigabit Ethernet

• Low Input Noise Current

• Differential Output

• Single 5V Supply with On-chip biasing
for photodetectors

General Description

The VSC7711 Transimpedance Amplifiers provide a high performance solution for amplifying high speed

photodetector output signals from a fiber optic communications channel into a differential output voltage. The

benefits of Vitesse Semiconductor’s Gallium Arsenide H-GaAs III process are fully utilized to provide a very
high bandwidth and low noise amplifier. The detector bias is supplied on-chip eliminating the need for a sepa­rate bias connection. The sensitivity, duty cycle distortion and jitter meet or exceed all Fibre Channel and Giga­bit Ethernet requirements.

In conjunction with suitable photodetectors, these parts can be easily used in developing a wide range of
Fibre Channel and Gigabit Ethernet optoelectronic receivers for both short wavelength (850nm) as well as long
wavelength (1300nm) applications.

Part Number

Data Rate

(Gb/s)

Bandwidth

(MHz)

Transimpedance

(k

Ω)

Input Noise

(nA RMS)

VSC7711 1.25 800 3.5 180

D0

D1

+5V

Block Diagram:

Photodetector/Transimpedance Amplifier

+

_

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7711

Transimpedance Amplifier

Family for Optical Communication

Page 2 

VITESSE SEMICONDUCTOR CORPORATION

G52178-0, Rev 2.1

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

Table 1: Electrical Characteristics of Transimpedance Amplifiers

(VS = 5V & T = 25°C unless otherwise noted)

Table 2: Absolute Maximum Ratings

Table 3: Recommended Operating Conditions

Symbol Parameter Min. Max. Units Conditions

V

DD

Supply Voltage 4.5 5.5 V —

I

s

Supply Current — 62 mA I

in

4µApp to 1.5mA

pp

BW

Optical Modulation
Bandwidth

800 MHz I

in

= 20µA

pp,

detector capacitance = 0.6pf

F

c

Low Frequency Cutoff 1.5 MHz I

in

= 20µA

pp

Tr, T

f

Output Rise & Fall Time — 250 ps

20% to 80%
I

in

-1.0mA

pp

R

d

Differential Transresistance 3.5 — kΩ

R

L

= 100Ω, differential

I

in

= 20µA

I

max

Output Drive Current 1.5 — mA

pp

10% Duty Cycle Distortion

I

n

Input Noise Equivalent
Current

— 180 nA RMS BW = 800 MHz

I

n

Input Noise Equivalent
Current Spectral Density

—6.4pA/ √Hz BW = 800 MHz

PDJ Pattern Dependent Jitter — 60 ps

R

o

Single Ended Output
Impedance

25 75 Ω —

V

max

Maximum Differential
Output Voltage

—700MV

pp

I

in

= 1.0mA

pp

RL = 100Ω, differential

V

B

Output Bias Voltage 0.5 1.7 V —

V

off

Output Offset Voltage 0.15 V —

PSRR

Power Supply Rejection
Ratio

35 — dB f = 0.3MHz - 40MHz, with external filter

Symbol Parameter Limits

V

DD

Power Supply 6V

T

stg

Storage Temperature -55°C to 125°C (die temperature under bias)

Symbol Parameter Limits

V

DD

Power Supply 4.5-5.5V (5.0V nominal)

T

op

Operating Temperature 0°C (ambient) to 80°C (die)

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VITESSE SEMICONDUCTOR CORPORATION

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10/6/99 741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

VITESSE

SEMICONDUCTOR CORPORATION

dvance Product Information

SC7711

Transimpedance Amplifier

Family for Optical Communication

G52178-0, Rev. 2.1

Table 4: Pin Table Specifications for Bare Die

Figure 1: Schematic View of Bare Die Pad Assignments

Note: Refer to Figure 4 for die layout detail.

Symbol Description

D

+

OUT

Data output normal (with reference to incident light)

D

–

OUT

Data output complement (inverting) (with referenc e to incid ent lig ht)
VDD Power supply
GND Ground (package case)

GND

GND

ANODE

ANODE

CATHODE

D

+

OUT

D

–

OUT

VDD

VDD

VITESSE

SEMICONDUCTOR CORPORATION

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VSC7711

Transimpedance Amplifier

Family for Optical Communication

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VITESSE SEMICONDUCTOR CORPORATION

G52178-0, Rev 2.1

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

Thermal Resistance Calculation For Bare Die

In order to relate the junction temperature to the temperature of the back side of the bare die, the following

thermal characteristics of the package are provided

Table 5: Thermal Resistance Calculation for Bare Die.

Chip Size 0.168cm x 0.104cm Thermal Path

Chip Area A 0.015 cm

2

Die height (T

die

) 0.066 cm

Thermal Conductivities

K GaAs 0.55W / cm °C

θ

GaAs

8°C/W

== =

KGaAsA

T

die

0.066

0.55 x 0.015

θ

JB

= Thermal Resistance from Junction to back = 8°C/W

Example:

For VSC7711 at nominal supply current of 25mA and V

DD

= 5V

Tem

p

erature rise from junction to back = 0.025A x 5V x 8°C/W = 1°C

θ

GaAs

Tj

T

b

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VITESSE SEMICONDUCTOR CORPORATION

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10/6/99 741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

VITESSE

SEMICONDUCTOR CORPORATION

dvance Product Information

SC7711

Transimpedance Amplifier

Family for Optical Communication

G52178-0, Rev. 2.1

Figure 2: Mechanical Specifications

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7711

Transimpedance Amplifier

Family for Optical Communication

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VITESSE SEMICONDUCTOR CORPORATION

G52178-0, Rev 2.1

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

Table 6: Die Pad Descriptions

Ordering Information

Notice

This document contains information about a new product during its fabrication or early sampling phase of
development. The information in this document is based on design targets, simulation results or early prototype
test results. Characteristic data and other specifications are subject to change without notice. Therefore the
reader is cautioned to confirm that this datasheet is current prior to design or order placement.

Warning

Vi tesse Semico ndu ctor Co rporat ion’s products are not intended for use in life suppor t appl iances, de vic es or
systems. Use of a Vitesse product in such applications without the written consent is prohibited.

Pad

Number

Pad

Name

Pad Locations

Pad
Size

Pass

Opening

Pad

Finish

Finish

Thickness

X Y

1 ANODE 104.5 880 110 x 110 89 x 89 Gold 1500 Å
2 CLON 71.7 1440.6 110 x 110 89 x 89 Gold 15 00 Å
3 VDD 71.7 1601.2 110 x 110 89 x 89 Gold 1500 Å
4 VGND 790 1602.1 110 x 110 89 x 89 Gold 1500 Å
5 CLOP 790 1441.1 110 x 1 10 89 x 89 Gold 1500 Å
6 ANODE 765.9 781.2 110 x 110 89 x 89 Gold 1500 Å
7 CATHODE 764.3 595.8 110 x 2 01 89 x 180 Gold 1500 Å
8 VGND 5 95.4 55 246 x 110 223 x 86 Gold 1500 Å
9 VDD 258 55 246 x 110 223 x 86 Gold 1500 Å

10 CATHODE 428.5 530.5 522 x 522 310 x 310 Gold 1500 Å

Part Numbering Scheme:

VSC7711X

X Individual Die

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VITESSE SEMICONDUCTOR CORPORATION

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10/6/99 741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]

VITESSE

SEMICONDUCTOR CORPORATION

dvance Product Information

SC7711

Transimpedance Amplifier

Family for Optical Communication

G52178-0, Rev. 2.1

Notes on Measurement Conditions & Applications

Note 1:Measurement Setup for Frequency Response

Note 2:Bias T Schematic

DC

1

AC

1

AC

2

DC

2

DUT

Hybrid

Coupler

Optical

Attenuator

Laser

Lightwave Component

Analyzer HP8702

Bias T

Bias T

Power

Supply

AC Out

DC Out

Signal

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7711

Transimpedance Amplifier

Family for Optical Communication

Page 8 

VITESSE SEMICONDUCTOR CORPORATION

G52178-0, Rev 2.1

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]