MIC4834 Datasheet, PDF (1/12 Pages) Micrel Semiconductor – Low Noise Dual 220 VPP EL Driver

MIC4834
Low Noise Dual 220 V_PP EL Driver
General Description
The MIC4834 is a low noise dual Electroluminescent (EL)
Panel driver used in backlighting applications. The
MIC4834 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
MIC4834 incorporates internal wave-shaping circuitry
specifically designed to reduce audible noise emitted by
EL panels. With only one inductor the MIC4834 can drive
two outputs 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.
The MIC4834 features separate oscillators for the boost
and H-bridge stages. The boost frequency may be
adjusted with an external resistor to optimize efficiency
and brightness. The H-bridge frequency is internally preset
to 225Hz, to reduce the number of external components
and layout space.
The MIC4834 is available in 10 pin 3mmx3mm MLF^®
package as well as MSOP-10L, and has an operating
junction temperature range of –40°C to +125°C.
Features
• Drives two EL panels, up to 3 in² each at full
brightness
• 220V_PP regulated AC output waveform
• 2.3V to 5.8V DC input voltage
• Wave-shaping circuit to reduce audible noise
• Adjustable boost converter frequency
• Single inductor to power both panels
• 0.1µA typical shutdown current
• Package options
− 10-pin 3mmx3mm MLF^®
− 10-pin MSOP
• –40^oC to +125^oC junction temperature range
Applications
• Mobile phones
• MP3/portable media players (PMP)
• Clocks/ watches
• Remote controls
• Cordless phones
• GPS devices
• PDAs
_________________________________________________________________________________________________
Typical Application
Low Noise Dual EL Driver
MLF and MicroLead Frame are registered trademark of Amkor Technologies
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
October 2008
M9999-100808-A