MY9931

MY-Semi Preliminary MY9931 3 Channels Constant Current LED Driver With Cascade DMX512 Protocol and Differential Interface General Description Features The MY9931, 3 channels constant current LED driver with 14bits grayscale APDM (Adaptive Pulse Density Modulation) control, supports standard DMX512 protocol and fully differential interface suited for long distance cascade applications. The distinctive DMX512 decoding approach could decode precisely a standard DMX512 signal. The differential interface provides wide common-mode range to support long distance transmission without common-ground power systems. The device o p e r a t e s o v e r 7 V t o 4 0 V i n p u t v o l t a g e r a n g e a n d provides 3 open-drain constant current sinking outputs that are rated to 4 0 V and delivers up to 60mA of high accuracy current to each string of LED. The current at each output is programmable by means of three external current setting resistors. The MY9931 provides the gamma correction, gamma value is 2.2, to transform 8bits DMX data to 14bits APDM data in order to enhance brightness contract. The 14bits adaptive pulse density modulation makes sure that the frame refresh rate is higher than 2KHz. And an accurate oscillator is built in for free running APDM grayscale control and DMX512 decoder. The POL function makes MY9931 as a PWM generator to support driving high power LEDs. MY9931 is available in SOP16 packages and specified over the -40°C to +85°C ambient temperature range. ...