ST2226B

ST2226B Version : A.002 Issue Date : 2005/02/23 File Name : SP-ST2226B-A.002.doc Total Pages: 20 PWM-Controlled Constant Current Driver for LED Displays 9 7 1 SILICON TOUCH TECHNOLOGY INC. 9-7F-1, Prosperity Road I, Science Based Industrial Pard, Hsin-Chu, Taiwan 300, R.O.C Tel：886-3-5645656 Fax：886-3-5645626 SILICON TOUCH TECHNOLOGY INC. ST2226B ST2226B PWM-Controlled Constant Current Driver for LED Displays General Description The ST2226B is a LED driver incorporating shift registers, data latches, 16-channel constant current circuitry with current value set by an external resistor, 1024 gray level PWM (Pulse Width Modulation) functional unit and time division capability. Each channel can provide a maximum current of 60 mA. Time division operation allows driving up to 1 or 2 LEDs with a single output channel (mode-1 and mode-2 respectively). Block Diagram. IOUT0 …… IOUT15 Rext Voltage Reference Driver (16-Channel) GCLK PWM Counter Comparator (16-Channel) CMD[2:0] DCLK DIN Operation Control Shift Register and Latch (10 Bit ｘ 16-Channel ｘ 2LED) DOUT Figure 1. Functional block diagram ST2226B Version：A.002 Page：1 SILICON TOUCH TECHNOLOGY INC. ST2226B Features ˙ Constant current outputs with current value settings by an external resistor ˙ Maximum output current: 60 mA ˙ Time division output allows the driving of 1 or 2 LEDs with a single output ˙ Maximum / minimum output voltage: 17V / 1.25V ˙ 10 bits luminance data with PWM current outputs ˙ Se...