MIC4834YMM Microchip

MIC4834 Low Noise Dual 220 V EL Driver PP General Description Features 2 The MIC4834 is a low noise dual Electroluminescent (EL) Drives two EL panels, up to 3 in each at full Panel driver used in backlighting applications. The brightness MIC4834 converts a low DC voltage to a high DC voltage 220V regulated AC output waveform PP using a boost converter and then alternates the high DC 2.3V to 5.8V DC input voltage voltage across the EL panels using an H-bridge. The Wave-shaping circuit to reduce audible noise MIC4834 incorporates internal wave-shaping circuitry Adjustable boost converter frequency specifically designed to reduce audible noise emitted by Single inductor to power both panels EL panels. With only one inductor the MIC4834 can drive 0.1A typical shutdown current two outputs and requires a minimum number of passive Package options components. It features an operating input voltage range 10-pin 3mmx3mm MLF of 2.3V to 5.8V, making it suitable for 1-cell Li-ion and 2- or 10-pin MSOP 3-cell alkaline/NiCad/NiMH battery applications. o o 40 C to +125 C junction temperature range The MIC4834 features separate oscillators for the boost and H-bridge stages. The boost frequency may be Applications adjusted with an external resistor to optimize efficiency and brightness. The H-bridge frequency is internally preset Mobile phones to 225Hz, to reduce the number of external components MP3/portable media players (PMP) and layout space. Clocks/ watches The MIC4834 is available in 10 pin 3mmx3mm MLF Remote controls package as well as MSOP-10L, and has an operating Cordless phones junction temperature range of 40 C to +125C. 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 +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel MIC4834 Ordering Information Part Number Package Operating Junction Temp Range Lead Finish MIC4834YML 10 pin (3mm x 3mm) MLF -40C to +125C Pb-free / RoHS-Compliant MIC4834YMM 10-Pin MSOP -40C to +125C Pb-free / RoHS-Compliant Pin Configuration 10-Pin MLF - Top View 10-Pin MSOP Top View Pin Description Pin Number Pin Name Pin Function 1 ENA EL Panel A Enable Pin: Logic high enables ELA and logic low disables ELA output. 2 VDD DC Input Supply Voltage: 2.3V to 5.8V 3 RSW RSW pin: Sets internal boost converter switch frequency by connecting an external resistor (R ) to VDD. Connecting the R resistor to GND shuts down the device. SW SW 4 ENB EL Panel B enable pin: Logic high enables ELB and logic low disables ELB output. 5 GND Ground. 6 SW Switch Node: Drain of internal high-voltage power MOSFET for boost circuit. 7 CS Regulated Boost Output: Connect to the output capacitor of the boost regulator and to the cathode of the diode. 8 COM EL output: Common EL output terminal to both ELA and ELB. Connect one end of each EL panel to this pin. 9 ELB EL Panel B output: Connect the other end of the EL panel B to this pin. 10 ELA EL Panel A output: Connect the other end of the EL panel A to this pin. EPad HS Pad Heat Sink Pad. Connect to ground externally. MLF package only. M9999-100908-A October 2008 2