The Supertex HV856 is a high voltage, triple EL lamp driver designed for driving combined EL lamps of up to 3.0in2 (1.0 in2 each). It is a higher voltage version of the HV858. The input supply voltage range is from 1.8V to 6.5V. The device is designed so that the input voltage to the inductor can differ from the input voltage to the device (split supply). The device uses a single inductor and a minimum number of passive components. The nominal regulated output voltage that is applied to the EL lamp is 105V. The HV856 has two internal oscillators; one for the internal switching MOSFET and the other for the high voltage EL lamp driver. The EL lamp frequency is fixed internally at 500Hz. The power converter oscillator runs 256 times faster than the EL lamp driver at 128kHz.