Low Noise, High Voltage EL Lamp Driver IC

The Supertex HV857 is a high voltage driver designed for driving Electroluminescent (EL) lamps of up to 5 square inches. The input supply voltage range is from 1.8V to 5.0V. 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 95V. The chip CAN be enabled/disabled by connecting the resistor on RSW-Osc to VDD/GND. The HV857 has two internal Oscillators a switching MOSFET and a high voltage EL lamp driver. The frequency for the switching MOSFET is set by an external resistor connected between the RSW-Osc pin and the supply pin VDD. The EL lamp driver frequency is set by an external resistor connected between REL- Osc pin and VDD pin. An external inductor is connected between the LX and VDD pins or V for split supply applications. A 0.003- IN 0.1F capacitor is connected between CS and ground. The EL lamp is connected between VA and VB. By Supertex, Inc.