DM621

DM621 Version : A.007 Issue Date : 2010/08/03 File Name : SP-DM621-A.007.doc Total Pages : 22 12-CHANNELS PRE-PROGRAMMABLE CONSTANT CURRENT LED DRIVER 9 7 1 SILICON TOUCH TECHNOLOGY INC. 9-7F-1, Prosperity Road I, Science Based Industrial Park, Hsin-Chu, Taiwan 300, R.O.C. Tel：886-3-5645656 Fax：886-3-5645626 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 po...