Macroblock MBI5158 PWM Time-Multiplexing LED Driver

Description

• 3V-5.5V supply voltage
• 16 constant current output channels
• Constant output current range:
  – 1~20mA @ 5V supply voltage
  – 1~15mA @ 3.3V supply voltage
• Excellent output current accuracy:
  Between channels:：<±2.5％(Max.)
  Between ICs: <±3％(Max.)
• Digital Power-On-Reset
• Built-in 16K-bit SRAM to support time-multiplexing for 1 ~ 32 scans
• 14-bit /13-bit color depth PWM control to improve visual refresh rate
• 6-bit current gain，12.5%~100%
• LED failure isolation
  -LED failure induced cross elimination
• Compulsory LED open detection
• Integrating ghost elimination circuit
• Improvement of high contrast interference
• GCLK multiplier technology
• Support double refresh mode
• Maximum data clock frequency: 30MHz@VDD=5V
• Maximum gray-scale clock frequency: 33MHz @VDD=5V

MBI5158 is designed for LED video applications using internal Pulse Width Modulation (PWM) control with selectable 14-bit / 13-bit color depth. MBI5158 features a 16-bit shift register which converts serial input data into each pixel’s gray scale 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 1:32 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, MBI5158 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. MBI5158 drives the corresponding LEDs to the brightness specified by image data. With MBI5158, all output
channels can be built with 14-bit color depth. When building a 14-bit color depth video, S-PWM technology reduces the flickers and improves the image fidelity.

Through compulsory error detection, MBI5158 detects individual LED for open-circuit errors without extra components. MBI5158 equipped an innovative cross elimination function, and it solves the cross phenomenon induced by failure LEDs. Besides, integrated ghost elimination and high contrast interference circuit eases the ghost
problems and improve image contrast.