AIC1652

AIC1652 MICROPOWER INVERTING DC/DC CONVERTER SPEC NO: DS-1652-02 DEC 27, 00 n FEATURES l l l l l l l n DESCRIPTION The AIC1652 is a high performance inverting DC/DC converter, designed to drive an external power switch to generate programmable negative voltages. In the particularly suitable LCD bias contrast application, efficiency of 87% can be achieved with low cost PNP bipolar transistor drivers. Output voltage can be scaled to -40V or greater by two external resistors. A pulse frequency modulation scheme is employed to maintain high efficiency conversion under wide input voltage range. Quiescent current is about 80µA and can be reduced to 0.7µA in shutdown mode. Switching frequency being around 70KHz to 160KHz range, small size switching components are ideal for battery powered portable equipments, like notebook and palmtop computers. 2.4V to 7V Input Voltage Operation. Adjustable Output Voltage up to -40V. Low Quiescent Current at 80µA. Pulse Frequency Modulation Maintains High Efficiency (87%). 70KHz to 160KHz Switching Frequency. Power-Saving Shutdown Mode (0.7µA Typical). High Efficiency with Low Cost External PNP Bipolar Transistor. n APPLICATIONS l Negative LCD Contrast Bias for 1. Notebook & Palmtop Computers. 2. Pen-Based Data System. 3. Portable Data Collection Terminals. 4. Personal Digital Assistants. Negative Voltage Supply. l n TYPICAL APPLICATION CIRCUIT VIN 2.4V ~ 7V 100µF + C1 VIN VREF CL DHI RB 470~1.8K 150µ H *L 100µF C2 + Q1 9012 D1 AIC1652 SHDN ...