16-Bit Serial Input, Constant-Current

Latched LED Driver

A6276

3

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Copyright © 2000, 2003 Allegro MicroSystems, Inc.

Terminal Description

Terminal No.

Terminal Name

Function

1

GND

Reference terminal for control logic.

2

SERIAL DATA IN

Serial-data input to the shift-register.

3

CLOCK

Clock input terminal for data shift on rising edge.

4

LATCH ENABLE

Data strobe input terminal; serial data is latched with high-level input.

5-20

The 16 current-sinking output terminals.

21

OUTPUT ENABLE

When (active) low, the output drivers are enabled; when high, all output

drivers are turned OFF (blanked).

22

SERIAL DATA OUT

CMOS serial-data output to the following shift-register.

23

An external resistor at this terminal establishes the output current for all

sink drivers.

24

SUPPLY

GROUND

REGISTER

LATCHES

1

2

3

18

19

20

21

23

4

5

6

7

22

24

SERIAL

DATA OUT

LOGIC

SUPPLY

SERIAL

DATA IN

OUTPUT

ENABLE

LATCH

ENABLE

CLOCK

CK

OE

I

REGULATOR

L

O

12

9

10

11

13

14

15

16

8

17

Pin-out Diagram

(A, LP, and LW packages)