Microchip | MIC4827YMM

Micrel’s MIC4827YMM is a high output voltage, DC to AC converter, designed for driving EL (Electroluminescent) lamps. The device operates from an input voltage range of 1.8 V to 5.5 V, making it suitable for 1-cell Li Ion and 2- or 3-cell alkaline/NiCad/NiMH battery applications. The MIC4827 converts a low voltage DC input to a 180 VPP AC output signal that drives the EL lamp.

The MIC4827 is comprised of two stages: a boost stage, and an H-bridge, lamp driver, stage. The boost stage steps the input voltage up to +90 V. The H-bridge stage then alternately switches the +90 V output to each terminal of the EL lamp, thus creating a 180 VPP AC signal to drive the EL lamp and generate light. The MIC4827 features separate oscillators for the boost- and H-bridge stages. External resistors independently set the operating frequency of each stage. This flexibility allows the EL lamp circuit to be optimized for maximum efficiency and brightness. The MIC4827 uses a single inductor and a minimum number of external components, making it ideal for portable, space-sensitive applications. The MIC4827 is available in an 8-pin MSOP package with an ambient temperature range of –40°C to +85°C.

Key Features:

• 1.8 V to 5.5 V DC input voltage.
• 180 VPP regulated AC output waveform.
• Independently adjustable EL lamp frequency.
• Independently adjustable boost converter frequency.
• 0.1 µA shutdown current.

Applications:

• LCD panel backlight.
• Cellular phones.
• PDAs.
• Pagers.
• Calculators.
• Remote controls.
• Portable phones.