The MIC5400 consists of two banks of 8 LED driver outputs, each output capable of sinking up to 30mA. Each bank is intended to drive 8 LED pixels of the same color. Most applications will use the MIC5400 to drive pixel clusters of 4 LEDs [RRGB] Typically two red LEDs are used for every one green and blue to compensate for red LED brightness.
A single external resistor sets maximum drive current. Use of an external resistor allows different color LED banks to be biased to the same intensity. Brightness control is digitally programmed through the serial interface. Coarse brightness control is determined by two 4-bit DACs, one for each driver bank, limiting the full-scale output to a fraction of the maximum value. Additionally, each output has fine brightness control using 10-bit resolution PWM.
Groups of drivers can be cascaded in daisy chain fashion. Open circuit output faults are detected and can be read back from the internal status register.
Two banks of 8 outputs
Current sink: 30mA
Programmable brightness control
Coarse: 4-bit resolution DAC
Fine: 10-bit resolution PWM
Resistors sets maximum LED current to compensate variation in LEDs
Current limit on each output
Watchdog disables output under fault condition
Power-on reset (all LED's Off)
Soft-start on power up and watchdog recovery
Output open fault detention with status register readback
Output transitions are staggered to minimize supply transients