Inverter Reduces Audible Noise When Driving EL Lamps

With ±15 kV of ESD protection, the MAX4990E dc-to-ac converter for driving electroluminescent (EL) lamps employs an inductor-based boost converter to generate 250 Vp-p. Promising to maximize design flexibility, the device provides resistor-adjustable slew-rate control for audible-noise reduction, capacitor-adjustable switching frequencies, and multiple options for controlling output voltage. The proprietary, acoustic-noise-reduction circuit controls ac-voltage slew rate to reduce audible noise from the lamp. To determine optimal values for passive components, users can control boost-converter and lamp switching frequencies via an external source, i.e., a PWM signal, or capacitors. Operating in temperatures from -40°C to +85°C and available in a 14-pin, 3 mm x 3 mm TDFN package, prices start at $0.99 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.