VITESSE

SEMICONDUCTOR CORPORATION

Preliminary Data Sheet

VSC7940

SONET/SDH 3.125Gb/s

Laser Diode Driver with Automatic Power Control

Page 2

G52357-0, Rev 3.2

05/11/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

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

Internet: www.vitesse.com

Electrical Characteristics

Table 1: AC Specifications

AC specifications are guaranteed by design and characterization. Typical values are for 5V operation.

NOTES: (1) Measured with 622Mb/s 0-1 pattern, LATCH=high. (2) PWD = (wider pulse - narrower pulse) / 2).

Table 2: DC Specifications

Symbol

Parameter

Min

Typ

Max

Units

Conditions

Input Latch Setup Time

100

ps

LATCH=high

Input Latch Hold Time

100

ps

LATCH=high

Enable/Start-up Delay

250

ns

Output Rise Time

TBD

TBD

ps

20% to 80%

Output Fall Time

TBD

TBD

ps

20% to 80%

PWD

Pulse Width Distortion

10

50

ps

See Notes 1, 2

Maximum Consecutive Identical Digits

80

bits

Jitter Generation

7

20

Jitter BW=12kHz to 20MHz,

0-1 pattern.

Symbol

Parameter

Min

Typ

Max

Units

Conditions

Power Supply Voltage

4.75

5.0

5.25

V

Power Supply Current

TBD

45

mA

Bias Current Range

1

100

mA

100

µA

ENABLE=low or

Bias Current Stability

230

ppm/

°C

900

Bias Current Absolute Accuracy

±15

%

Refers to part-to-part variation

Monitor Diode Reverse Bias Voltage

1.5

V

Monitor Diode Reverse Current Range

18

1000

µA

Monitor Diode Bias Setpoint Stability

-480

-50

480

ppm/

°C

(2)

90

(2)

Monitor Diode Bias Absolute Accuracy

-15

15

%

Refers to part-to-part variation

Modulation Current Range

5

100

mA

200

µA

ENABLE=low or

Modulation Current Absolute Accuracy

±15

%

See Note 2