12-Channels Pre-programmable Constant Current LED Driver

Version:A.007

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DM621

DM621

12-CHANNELS PRE-PROGRAMMABLE

CONSTANT CURRENT LED DRIVER

General Description

The DM621 is an innovative LED driver that integrates a new data transmit interface to

accomplish 2-wires control for lighting applications. By the combination of SIN and

DCK, DM621 could be pre-programmed to set the operating modes that involve GCK

frequency division, PWM grayscale selection, inverse IOUT PWM signal, and GCK

frequency selection. DM621 also provides the auto-latch function and incorporates a

particular PWM method (AS-PWM). The IOUT waveform is averagely divided into 16

sections in order to reduce the flickers and enhance the visual refresh rate. The DM621

could also be constructed as a PWM controller for LED drivers. In this case, resistors

must be connected at output pins to achieve this function (Fig.18).

This chip incorporates 4x3-channel constant current circuitry with current value set by

3 external resistors and 256/1024/4096/16384 gray scale PWM function unit. Each

channel provides a maximum current of 90mA. The maximum output sustaining voltage

of 28V would make more serial LEDs possible. And DM621 also integrates an internal

regulator to make power supply voltage up to 12V. Meanwhile, retiming of DCKO and

SOUT is advantageous in the LED decorating and long-cascade applications.

Features

4 x 3(R/G/B) Output Channels

8/10/12/14-bits PWM grayscale Control

Maximum Clock Frequency: 20MHz

Constant Current Output: 5mA to 90mA

Maximum Output Sustaining voltage: 28V

Power Supply Voltage: 5V to 12V

Average Separated IOUT PWM Waveform

Auto-latch

Function

Retiming of DCKO and SOUT

for long cascade applications

Serial Shift-In Architecture for Data of Grayscale, frequency Division and PWM bit number

Incorporating internal GCK oscillator 12MHz (Refresh rate = 46.8KHz @ 8-bits PWM)

Package: TSSOP24 (with thermal pad), QFN20 (with thermal pad)