Used for powering electroluminescent (EL) lamps for backlighting LCDs and keypads in cellular phones and other wireless communication devices, the SP4438 driver features clipped-sinusoid waveform, with gradual rising and falling edges, to obtain low acoustic noise. The output waveform, combined with constant current to the lamp and low-frequency operation, also minimizes electromagnetic interference and stress on the lamp to extend lamp lifetime. The SP4438 operates from a 2.7V to 3.3V supply and is designed to drive cell-phone-sized lamps from 1 to 3 sq. in. in size. One external resistor is used to set the internal oscillator frequency, and one inductor is required to generate the high-voltage ac output to drive the EL lamp. The SP4438 also has a standby mode that draws less than 1 µA. And the device is offered in a space-saving 8-pin MSOP package, with all input pins ESD protected with internal diodes to VDD and VSS. The SP4438EU is available starting at $1.07 each/10K.