HV803

The Supertex HV803 is a high-voltage driver designed for driving EL lamps of up to 30nF. EL lamps greater than 30nF can be driven for applications not requiring high brightness. The input supply voltage range is from 2.4 to 9.5V. 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 ±90V. The chip can be enabled by connecting the resistors on R _SW-osc and R _EL-osc to V_DD and disabled when connected to GND.

The HV803 has two internal oscillators, a switching MOSFET, and a high-voltage EL lamp driver. The frequency for the switching converter MOSFET is set by an external resistor connected between the RSW-osc pin and the supply pin V_DD. The EL lamp driver frequency is set by an external resistor connected between R _EL-osc pin and the V_DD pin. An external inductor is connected between the Lx and V_DD pins. A 0.01F to 0.1F capacitor is connected between CS and GND pins. The EL lamp is connected between V_A and V_B pins.

The switching MOSFET HV803 charges the external inductor and discharges it into the Cs capacitor. The voltage at Cs will start to increase. Once the voltage at Cs reaches a nominal value of 90V, the switching MOSFET is turned OFF to conserve power. The outputs V_A and V_B are configured as an H-bridge and are switched in opposite states to achieve 180V peak-to-peak across the EL lamp.