Date: 10/08/2011

8-channel constant current LED display driver IC from Holtek

Holtek has released an 8-channel constant current LED display driver IC, the HT16D595, which improves the disadvantages of uneven illumination levels and high failure rates as well as offering pin and system instruction compatibility with that of traditional 8-channel constant voltage drivers.

Holtek explains that the HT16D595 is equipped with a 48mA±6% constant current drive output providing constant LED display illumination levels even when the LED forward voltages are different and the outputs can withstand voltages of up to 17V greatly reducing the failure rates of the LED display. An internal CMOS shift register and latch function can convert the serial input data to a parallel output data format. The current will vary with the external output voltage (VDS) variations but can be controlled to within 0.5% for each voltage change or to within 1% for the supply voltage (VDD) and the high clock frequency rate of 25MHz can support systems with high volume data transmission requirements. When the VLED voltage is 4V, the LED display power consumption can be reduced by 20%, which also additionally reduces the IC temperature.

The target applications for the HT16D595 device are those, which include high level single/double color LED character displays, for which there are many.