8-BIT SERIAL-INPUT, CONSTANT-

CURRENT LATCHED LED DRIVER

Always order by complete part number, e.g., A6277EA .

The A6277x is specifically designed for LED-display applications.

Each BiCMOS device includes an 8-bit CMOS shift register, accompa-

nying data latches, and eight npn constant-current sink drivers. Two

package styles and two operating temperature ranges are available.

The CMOS shift register and latches allow direct interfacing with

microprocessor-based systems. With a 5 V logic supply, typical serial

data-input rates are up to 20 MHz. The LED drive current is deter-

mined by the user’s selection of a single resistor. A CMOS serial data

output permits cascade connections in applications requiring additional

drive lines. For inter-digit blanking, all output drivers can be disabled

with an ENABLE input high. In addition, a HIGH/LOW function

enables full selected current with the application of a logic low, or 50%

selected current with the application of a logic high.

The first character of the part number suffix determines the device

operating temperature range. Suffix ‘E–’ is for -40

°C to +85°C, and

suffix ‘S–’ is -20

°C to +85°C. Two package styles are provided for

through-hole DIP (suffix ‘–A’) or surface-mount SOIC (suffix ‘–LW’)

applications. The copper lead frame and low logic-power dissipation

allow the dual in-line package to sink 122 mA through all outputs

continuously over the operating temperature range (1.0 V drop,

+85

°C).

Note that the A6277EA (DIP) and the A6277ELW

(SOIC) are electrically identical and share a

common terminal number assignment.

ABSOLUTE MAXIMUM RATINGS

Output Voltage Range,

Input Voltage Range,

Package Power Dissipation,

Suffix ‘S-’ ................ -20

Suffix ‘E-’ ................ -40

Storage Temperature Range,

Caution: These CMOS devices have input

static protection (Class 2) but are still suscep-

tible to damage if exposed to extremely high

static electrical charges.

6277

PRELIMINARY INFORMATION

(Subject to change without notice)

July 20, 2000

FEATURES

I To 150 mA Constant-Current Outputs

I 24 V Outputs

I Under-Voltage Lockout

I Low-Power CMOS Logic and Latches

I High Data Input Rate

I Similar to Toshiba TD62715FN

I High/Low Output Current Function

A6277ELW

REGISTER

LATCHES

5

10

11

12

13

14

15

6

7

8

9

16

POWER

GROUND

POWER

GROUND

HIGH/LOW

(CURRENT)

Dwg. PP-029-17A

LOGIC

GROUND

1

2

3

17

19

4

18

20

SERIAL

DATA OUT

LOGIC

SUPPLY

SERIAL

DATA IN

OUTPUT

ENABLE

LATCH

ENABLE

CLOCK

CK

OE

I

REGULATOR

L

O

SUB

SUB

SERIAL

1

FF