Advanced

SP8107

Rev. 09/05/03

SP8107 – Three Channel Laser Driver

Copyright 2003 Sipex Corporation

SIPEX RESERVES THE RIGHT TO MAKE CHANGES TO THIS DATASHEET. CALL FOR UPDATES: 1-978-667-8700.

SIPEX CONFIDENTIAL, ADVANCED & PROPRIETARY. DO NOT DISTRIBUTE OR

COPY

page

PIN ASSIGNMENTS

Pin

Number

Pin

Name

Pin Function

1

IR

Read Channel current controlled input

2

I2

Write Channel 2 current controlled input

3

I3

Write Channel 3 current controlled input

4

RF

Connection of an external resistor to GND to set oscillator frequency

5

EN2

Write Channel 2 enable input with an internal pull-up resistor. Logic high or

floating turns channel off.

6

EN3

Write Channel 3 enable input with an internal pull-up resistor. Logic high or

floating turns channel off.

7

ENABLE

Common device enable input with pull-down resistor. Logic low or floating

turns device off.

8

OSCEN

Oscillator enable input with pull-down resistor. Logic low or floating turns

oscillator off.

9

Vcc

Supply voltage. Bypass to GND with 0.1uF ceramic capacitor

10

SELA

Output select input with pull-down resistor. Logic high selects output A, low or

floating selects output B

11

Output current source B for a laser diode

12

RSB

Connection of an external resistor to GND to set oscillator swing at the output B

13

RSA

Connection of an external resistor to GND to set oscillator swing at the output A

14

GND

Ground pin

15

Output current source A for a laser diode

16

Vcc

Supply voltage. Bypass to GND with ceramic capacitors 0.1 and 0.01uF in

parallel

BOARD LAYOUT AND GROUNDING

To obtain the best performance from the SP8107, a printed circuit board with ground plane is required.

Layout should ensure that analog signal lines (IR, I2, and I3) are separated as much as possible from

digital and output power lines. Output power lines should be as short and wide as possible. High quality,

low series resistance ceramic 0.1 and 0.01uF bypass capacitors should be used at the Vcc pins 9 and 16.

These capacitors must be located as close to the pins as possible. The traces connecting the pins and the

bypassing capacitors must be kept short and should be made as wide as possible.