SP4405

® SP4405 Low Voltage Electroluminescent Lamp Driver with Regulated Output Voltage s +2.2V to +4.5V Battery Operation s DC-to-AC Converter Produces 160VPP typical for EL Display Panels s Single Resistor Controlled Internal Oscillator s Low Current Standby Mode s Internal Feedback Loop Maintains a Constant Regulated EL Lamp Voltage Output APPLICATIONS s Pagers s Cellular Phones s PDAs DESCRIPTION The SP4405 is a high voltage output DC-AC inverter specifically designed to drive electroluminescent lamps to backlight liquid crystal displays, keypads, and backlit readouts used in battery operated portable equipment. The SP4405 will operate from a +2.2V to +4.5V battery source. The device features an internal feedback loop that regulates the lamp voltage output to 160VPP (typical) with varying supply voltages to maintain constant EL lamp brightness over the life of the battery. The device also has a low power shutdown mode which draws less than 50nA (typical), ideal for low power portable products. One external inductor is required to generate the high voltage AC output. One external resistor is used to set the internal oscillator frequency. The SP4405 is ideal for portable applications such as pagers, cellular phones, PDAs, and other portable applications using LCDs in dim or low light environments. The SP4405 is offered in 8-pin SOIC and 8-pin µSOIC packages. VBATTERY ELEN 1 VSS 2 COIL 3 EL1 4 SP4405 8 ROSC 7 CINT 6 5 VDD EL2 C1 0.1µF ELEN 1 L1 470µH SP4405 VDD ROSC 450kΩ ...