DESCRIPTION
The SP4438 device is a low noise, high voltage output DC-AC inverter designed to drive electroluminescent lamps to backlight liquid crystal display and keypads used in cellular phones, cordless phones, 2-way radios, and other wireless communication products. The output waveform of the SP4438 device is ideal for cell phone applications requiring low acoustic noise performance. 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 an EL lamp up to 3 square inches in size. The SP4438 operates from a +3.0V battery source and has a low power standby mode that draws less than 1µA, making it ideal for low-power cellular applications. All input pins are ESD protected with internal diodes to VDD and VSS. The SP4438 is offered in a space-saving 8-pin MSOP package.

■ Patent Pending Output Waveshaping
■ Waveshaped Output Optimized For Low Acoustic Noise And Maximum Efficiency
■ Reduced Supply Current And Standby Current
■ Up to15cd/m2 For Cell Phone Sized EL Lamps (2 to 3 sq. in.)
■ Waveshaped Output And Low Frequency Operation Minimize Stress On EL Lamp To Extend Its Lifetime
■ Uses 820µH, Sub-2mm Coils
■ Gradual Rising And Falling Edges Minimizes EMI
■ +2.7V To +3.3V Battery Operation
■ Space-Saving 8-pin MSOP package

APPLICATIONS
■ Cellular Radios
■ Wireless Communication Products