Single +5V, Fully Integrated,

155Mbps Laser Diode Driver

4

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______________________________________________________________Pin Description

NAME

FUNCTION

PIN

10

ENB+

Noninverting Enable TTL Input. Output currents are enabled only when ENB+ is high and

ENB- is low.

1

VREF2

Temperature-Compensated Reference Output. VREF2 is internally connected to VREF1.

12

OSADJ

Overshoot-Adjust Input. Connect to internal voltage reference through a resistor to adjust the

overshoot of the modulation output signal (see

Typical Operating Characteristics).

11

VREF1

Temperature-Compensated Reference Output. VREF1 is internally connected to VREF2.

13

IBIASFB

Bias-Feedback Current Output. Output from automatic power-control circuit. Connect to

14

IBIASSET

Laser Bias Current-Programming Input. Connect to internal voltage reference through a resis-

tor to set bias current (see

Typical Operating Characteristics).

15

IMODSET

Laser Modulation Current-Programming Input. Connect to internal voltage reference through

a resistor to set modulation current (see

Typical Operating Characteristics).

16

IBIASOUT

Laser Bias Current Output. Connect to laser cathode through an R-L filter network (see the

Bias Network Compensation section).

17, 19, 21

GNDA

Ground for Bias and Modulation Current Drivers

22

VCCA

+5V Supply Voltage for Bias and Modulation Current Drivers. Connect VCCA to the same

potential as VCCB, but provide separate bypassing for VCCA and VCCB.

20

OUT+

9

ENB-

Inverting Enable TTL Input. Output currents are enabled only when ENB+ is high and ENB- is low.

8

VCCB

+5V Supply Voltage for Voltage Reference and Automatic Power-Control Circuitry. Connect

VCCB to the same potential as VCCA, but provide separate bypassing for VCCA and VCCB.

6

VIN-

Inverting PECL Data Input

5

VIN+

Noninverting PECL Data Input

4, 7

GNDB

Ground for Voltage Reference and Automatic Power-Control Circuitry

3

FAILOUT

Failout Output. Active-low, open-collector TTL output indicates if automatic power-control

loop is out of regulation due to insufficient monitor-diode current (when VPIN is below the

2.6V threshold). Connect FAILOUT to VCC through a 2.7k

Ω pull-up resistor.

2

IPINSET

Monitor Photodiode Programming Input. Connect INPINSET to VREF1 or VREF2 through a

resistor to set the monitor current when using automatic power control (see

Typical Operating

Characteristics).

18

OUT-

23

IPIN

Monitor Photodiode Current Input. Connect IPIN to photodiode’s anode.

24

SLWSTRT

Slow-Start Capacitor Input. Connect capacitor to ground or leave unconnected to set start-up