The Microchip MIC4833 is a low noise dual Electroluminescent (EL) Panel driver used in backlighting applications. The MIC4833 converts a low DC voltage to a high DC voltage using a boost converter and then alternates the high DC voltage across the EL panels using an H-bridge.
The MIC4833 incorporates internal wave-shaping circuitry specifically designed to reduce audible noise emitted by EL panels. The two EL panels may be dimmed by applying a PWM signal to the device. The MIC4833 drives two outputs from a single inductor and requires a minimum number of passive components. It features an operating input voltage range of 2.3 V to 5.8 V, making it suitable for 1-cell Li-ion and 2- or 3-cell alkaline/NiCad/NiMH battery applications.
An external resistor may be used to adjust the output voltage slew rate to reduce audible noise. The MIC4833 features separate oscillators for the boost and H-bridge stages to allow independent control. External resistors set the operating frequencies of each stage allowing the EL circuit to optimize efficiency and brightness.
- Drives two EL panels, up to 4 in2 each at full brightness
- Independent input control for each of the two panels and allows PWM dimming
- 220 Vpp regulated AC output waveform
- 2.3 V to 5.8 V DC input voltage
- Wave-shaping circuit to reduce audible noise
- Adjustable slew rate for audible noise reduction
- Independently adjustable boost converter and EL panel frequency
- Single inductor to power both panels
- 0.1 µA typical shutdown current
- 12 pin 3 mm x 3 mm MLF® package
- -40°C to +125°C junction temperature range
- Mobile Phones
- MP3 Players/Portable Media Players (PMP)
- Remote Controls
- Cordless Phones
- GPS Devices