MIC4833YML-TR Microchip

MIC4833 Low Noise Dual 220 V EL Driver PP With Output Voltage Slew Rate Control General Description Features 2 The MIC4833 is a low noise dual Electroluminescent (EL) Drives two EL panels, up to 4 in each at full Panel driver used in backlighting applications. The brightness MIC4833 converts a low DC voltage to a high DC voltage Independent input control for each of the two panels using a boost converter and then alternates the high DC and allows PWM dimming. voltage across the EL panels using an H-bridge. The 220Vpp regulated AC output waveform MIC4833 incorporates internal wave-shaping circuitry 2.3V to 5.8V DC input voltage specifically designed to reduce audible noise emitted by Wave-shaping circuit to reduce audible noise EL panels. The two EL panels may be dimmed by applying Adjustable slew rate for audible noise reduction a PWM signal to the device. The MIC4833 drives two Independently adjustable boost converter and EL outputs from a single inductor and requires a minimum panel frequency number of passive components. It features an operating Single inductor to power both panels input voltage range of 2.3V to 5.8V, making it suitable for 0.1uA typical shutdown current 1-cell Li-ion and 2- or 3-cell alkaline/NiCad/NiMH battery package 12 pin 3mmx3mm MLF applications. o o 40 C to +125 C junction temperature range An external resistor may be used to adjust the output Applications voltage slew rate to reduce audible noise. The MIC4833 features separate oscillators for the boost and H-bridge Mobile Phones stages to allow independent control. External resistors set MP3s/Portable Media Players (PMP) the operating frequencies of each stage allowing the EL Clocks/ Watches circuit to optimize efficiency and brightness. Remote Controls The MIC4833 is available in a 12 pin 3mmx3mm MLF Cordless Phones package, and has an operating junction temperature range GPS Devices of 40 C to +125C. PDAs Typical Application High 50k Low ENA SLEW VIN Li Ion VDD ELA EL Lamp A 3V to 4.2V 332k RSW ELB EL Lamp B 0.01F MIC4833 1.78M REL COM High High Low Low ENB CS GND SW VIN 220H Li Ion 3V to 4.2V 2.2nF 10F 250V 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 MIC4833 Ordering Information Package Operating Junction Temp Lead Finish Part Number Range 12 pin 3mmx3mm MIC4833YML Pb-free / RoHS Compliant -40C to +125C MLF Pin Configuration ENA 1 12 SLEW VDD 2 11 ELA RSW 3 10 ELB EP REL 4 9 COM ENB 5 8 CS GND 6 7 SW 12-Pin 3mm 3mm MLF (ML) 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 SW SW resistor to GND shuts down the device. 4 REL REL pin: Sets internal H-bridge driver frequency by connecting an external resistor (R ) to VDD. Connecting the R to GND disables EL EL the EL oscillator. 5 ENB EL Panel B enable pin: Logic high enables ELB and logic low disables ELB output. 6 GND Ground. 7 SW Switch Node: Drain of internal high-voltage power MOSFET for boost circuit. 8 CS Regulated Boost Output: Connect to the output capacitor of the boost regulator and to the cathode of the diode. 9 COM EL output: Common EL output terminal to both ELA and ELB. Connect one end of each EL panel to this pin. 10 ELB EL Panel B output: Connect the other end of the EL panel B to this pin. 11 ELA EL Panel A output: Connect the other end of the EL panel A to this pin. 12 SLEW Optional resistor to set output current drive to control slew rate of load. If left open, the default slew current limit is 5mA. EPad HS Pad Heat Sink Pad. Connect to ground externally. M9999-100308 October 2008 2 (408) 955-1690