Holtek HT7943/HT7945 New WLED Backlight Driver Devices
With the successful release of the HT7936~HT7939A, small-size panel WLED backlight driver devices, Holtek now announces the release of two new devices, the HT7943 and HT7945, for the Notebook/Tablet PC display WLED backlight driver application area.
The biggest difference between the new HT7943/HT7945 and the previous HT793x series is that they now contain a current controlling accuracy to within ±1.5% between each WLED. The HT7943 and HT7945 respectively provide 6-channel and 8-channel LED current interfaces, using a 40V process. A string of WLEDs can contain up to 11 WLEDs. The HT7943 and HT7945 can respectively drive up to 66 or 88 LEDs. Their operating frequencies can be chosen to be either 500kHz or 1MHz. The input voltage range is 4.5V to 26V. The maximum internal Power NMOS RDS(ON) value is 0.35 Ohms and the maximum rated current value is 2.2 Amps. By detecting the ISENX pin voltage, the HT7943 and HT7945 provide both WLED open circuit and short circuit protection. Additionally, the HT7943 and HT7945 also include over-voltage protection, current-limit protection and over-temperature protection as well as a UVLO function.
The HT7943 and HT7945 are supplied in 4mm x 4mm 20-pin and 24-pin QFN type packages respectively, which provide smaller outlines, reduced thickness and good heat dispersion properties.