IMP803

The IMP803 is an Electroluminescent (EL) lamp driver with the four EL lamp driving functions on-chip. These are the switch-mode power supply, its high-frequency oscillator, the high-voltage H-bridge lamp driver and its low-frequency oscillator. The IMP803 drives EL lamps of up to 30nF capacitance to high brightness; EL lamps with capacitances greater than 30nF can be driven, but will be lower in light output. The typical regulated output voltage that is applied to the EL lamp is 180V peak-topeak. The circuit requires few external components, a single inductor, single diode, two capacitors and three resistors. Two of these resistors set the frequency for two internal oscillators.

The IMP803 operates over a 2.0V to 6.5V supply voltage range. A regulated, low-power source can supply the low quiescent current of the IMP803. The inductor may be driven from an independent, unregulated supply voltage in dual supply applications.

An internal circuit shuts down the switching regulator when the lamp drive voltage reaches 180V peak-to-peak. This conserves power and extends battery life.

The IMP803 is available in MicroSO and SO-8 packages and in die or wafer form.