January 2005

1

MIC5400

MIC5400

Micrel

MIC5400

Dual, 8-Output, 14-Bit LED Video Display Driver

General Description

The MIC5400 consists of 2 banks of 8 LED driver outputs,

each output capable of sinking up to 30mA. Each bank is

intended to drive 8 LED pixels of the same color. Most

applications will use the MIC5400 to drive pixel clusters of 4

LEDs (RRGB.) Typically two red LEDs are used for every one

green and blue to compensate for red LED brightness.

A single external resistor sets maximum drive current. Use of

an external resistor allows different color LED banks to be

biased to the same intensity. Brightness control is digitally

programmed through the serial interface. Coarse Brightness

Control is determined by two 4-bit DACs, one for each driver

bank, limiting the full-scale output to a fraction of the maxi-

mum value. Additionally, each output has Fine Brightness

Control using 10-bit resolution PWM.

Groups of drivers can be cascaded in Daisy Chain fashion.

Open circuit output faults are detected and can be read back

from the internal Status register.

Typical Application

SHFTCLK

VDDA

VDDB

VDD

SHIFTIN

SHIFTOUT

LOAD

0.01µF

2.2µF

2.2µF

Output A

Logic

Control and

SRegister

Output B

BD_A

BD_B

330½

330½

MIC5400

BCP69

BCP69

Features

•2 banks of 8 outputs

• Output characteristics:

• Current sink: 30mA

– Programmable brightness control

• Coarse: 4-bit resolution DAC

• Fine: 10-bit resolution PWM

– Resistor sets maximum LED current to compensate

variation in LEDs

– Current limit on each output

• Full protection:

– Over-temperature shutdown

– Watchdog disables output under fault condition

– Power-on reset (all LEDs Off)

– Soft-start on power up and watchdog recovery

– Output open fault detection with status register

readback

• Output transitions are staggered to minimize supply

transients

Applications

• Outdoor video screen

• Large LED display

Ordering Information

Part Number

Junction Temp. Range

Package

MIC5400BWM

–40°C to +85°C

28-Pin Wide SOIC

MIC5400YWM

–40°C to +85°C

28-Pin Wide SOIC

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com