OVERVIEW

The SM8146AD1 is a dedicated EL (Electro Luminescence) driver IC, capable of driving EL sheet up to 30cm2 in size. The EL drive circuit uses a technique that generates smooth sine wave EL drive waveforms without an output resistor, which has the advantage of preventing EL sheet audible noise, eliminating the need for additional peripheral components and a corresponding drop in power efficiency. Also, the EL drive voltage is constant-voltage controlled and is unaffected by supply voltage fluctuations, so that there are no EL bright ness variations due to supply voltage changes. A dimming function is available under direct control from a microcontroller. The logic HIGH-level input voltage range (ENA, DIM pins) starts at 1.4V, allowing the device to be driven directly without external transistors from a Li-ion battery.

FEATURES

■ Sine wave EL drive waveforms for low audible noise

■ Constant EL drive voltage independent of supply voltage fluctuations

■ Separate coil and EL drive frequency adjustment

■ Enable function (ENA pin)

■ Dimming function (DIM pin)

■ Direct control capability using 1.8V system CPU (ENA, DIM pins) VIH = 1.4V (min, VDD = 2.5 to 5.5V)

■ 2.5 to 5.5V supply voltage range

■ 170Vp-p (typ) maximum EL drive voltage

■ 250Hz (typ) EL drive frequency (ROCE = 200kΩ)

■ 0.5mA (typ) operating current

■ 1.0µA (max) standby current

■ 220µH (typ) recommended inductance

■ Package: 10-pin SON

APPLICATIONS

■ Cellular phone

■ Portable audio equipment

■ Handy terminal

■ Other portable application