The 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 2.3V to 5.8V, 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.
Additional Features
Drives two EL panels, up to 4in² each at full brightness
Independent input control for each of the two panels and allows PWM dimming.
220VPP regulated AC output waveform
2.3V to 5.8V 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
0.1µA typical shutdown current
-40°C to +125°C junction temperature range
The 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 2.3V to 5.8V, 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.
Additional Features
- Drives two EL panels, up to 4in² each at full brightness
- Independent input control for each of the two panels and allows PWM dimming.
- 220VPP regulated AC output waveform
- 2.3V to 5.8V 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
- 0.1µA typical shutdown current
- -40°C to +125°C junction temperature range
