The TLC5905 is a constant current driver that incorporates shift register, data latch, constant current circuitry with a current value adjustable and 256 gray scale display that uses pulse width control. The output current can be selected as maximum 80 mA with 16 bits or 120 mA with 8 bit. The current value of the constant current output is set by one external resistor. After this device is mounted on a printed-circuit board (PCB), the brightness deviation between LED modules (ICs) can be adjusted using an external data input, and the brightness control for the panel can be accomplished by the brightness adjustment circuitry. Also, the device incorporates the output voltage monitor (OVM) used for LED open detection (LOD) by monitoring constant current output. Moreover, the device incorporates watchdog timer (WDT) circuitry, which turns constant current output off when the scan signal stops during dynamic scanning operation, and thermal shutdown (TSD) circuitry, which turns constant current output off when the junction temperature exceeds the limit.