4 or 3-Channel LED Driver With Grayscale Adaptive Pulse Density Modulation Control

The MY9291, 4 or 3-channel (R/G/B/W or R/G/B/Amber or R/G/B x 1) constant current APDM LED driver, operates over a 3V ~ 5.5V input voltage range. The device provides 4 or 3(selectable) open-drain constant current sinking outputs that are rated to 17V and delivers up to 350mA of high accuracy current to each string of LED. The current at each output is programmable by means of four external current setting resistors.

MY9291 features a 10MHz EMI reduction data clock input. MY9291 also offers a 2-wire serial interface to send the grayscale data, control command including 16/14/12/8-bit grayscale selection, output polarity selection for high power LED driving grayscale clock frequency division selection, output Tr/Tf timing selection, current output waveform selection, and to realize the internal-latch function. MY9291 provides adaptive pulse density modulation method to increase the visual refresh rate up to 2000 Hz @ 16-bit grayscale and reduce the flickers, and it also provides output polarity selection for high power LED driving. Moreover MY9291 utilizes clock duty recovery technique and pulse re-timing to help long distance and multiple cascading applications. MY9291 provides typical ±1.5% channel-to-channel LED current accuracy. Additional features include a ±0.1% regulated output current capability and fast output transient response.

MY9291 is available in a QFN20,SSOP20 and TSSOP20(Exposed Pad) packages and specified over the -40°C to +85°C ambient temperature range.