Macroblock

MBI5251 is designed for LED video applications using internal Pulse Width Modulation (PWM) control with selectable 16/15/14/13-bit grayscale resolution. With Macroblock’s proprietary S-PWM technology, it is able to reduce the flickers and improves the image fidelity. MBI5251 features a 16-bit shift register which converts serial input data into each pixel’s grayscale of the output port. Sixteen regulated current ports are designed to provide uniform and constant current sinks for driving LEDs with a wide range of VF variations. The output current can be preset through an external resistor. The innovative architecture with embedded SRAM is designed to support up to 1:8 time-multiplexing applications. Users only need to send the whole frame data once and to store in the embedded SRAM of the LED driver, instead of sending every time when the scan line is changed. It helps to save the data bandwidth and to achieve high grayscale with very low data clock rate. With scan-type Scrambled-PWM (S-PWM) technology, MBI5251 enhances PWM by scrambling the “on” time of each scan line into several “on” periods and sequentially drives each scan line for a short “on” period. The enhancement equivalently increases the visual refresh rate of scan-type LED displays. In addition, the innovative GCLK multiplier technique doubles visual refresh rate.

Through compulsory error detection, MBI5251 detects the individual LED for open-circuit errors without extra components. MBI5251 is equipped with an innovative cross elimination function, as it solves the cross phenomenon induced by failure LEDs. Besides, an integrated ghost elimination circuit eases the ghost problems.