點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC

.

新竹市科學園區展業一路9號7樓之1

9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.

Tel：886-3-5645656

Fax：886-3-5645626

16-channel 16-bit PWM Constant Current LED Driver

Version : A.003

Page 1

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DM634

DM634

16-CHANNEL CONSTANT CURRENT LED DRIVER

WITH PROGRAMMABLE PWM OUTPUTS

General Description

DM634 is a 16-channel constant current sink LED driver. Each channel has adjustable 16-bits

(65536 steps) grayscale PWM control current outputs. 7-bit global brightness control is included in

supporting user to adjust chip current easily. It incorporates shift registers, data latches, constant

current circuitry with current value set by an external resistor, selectable oscillator source for PWM

functioning, and built-in LED open/short detection circuit to detect error status. It supports thermal

alarm and shutdown function; system retrieve the message to indicate when junction temperature

over limitation of chip. It is specifically designed for LED display and lighting applications.

Features

Constant-current outputs: 5mA to 90mA

16-bit linear PWM control current output per channel

7-bit high accuracy global brightness control

Maximum output voltage: 17V

Maximum clock frequency: 25MHz

Selectable internal/external PWM reference clock

PWM free-running capability (refresh rate ~ 275 Hz with internal oscillator ~ 18 MHz)

Build-in real-time LED open/short detection

Thermal Alarm and Shotdown –

Alarm : Junction Temperature >110℃

Shutdown : Junction Temperature > 180℃

Package and pin assignment (except QFN32) compatible to conventional LED driver series

(ST2221C, DM134B/5B, DM13C)

Power supply voltage: 3.3V to 5.5 V

Applications

Indoor/Outdoor LED Video Display

LED Variable Message Signs (VMS) System

LED Decorative Lighting

Package Types

SOP24, SSOP24, TSSOP24E (with exposed pad)