AIC1639

AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ¡½ FEATURES l l l l l l l l ¡½ DESCRIPTION The AIC1639 is a high efficiency step-up DC/DC converter for applications using 1 to 4 battery cells. Only three external components are required to d eliver a fixed output voltage of 2.7, 3.0V, 3.3V, or 5V. The AIC1639 starts up from below 0.9V input with 1mA load. Pulse Frequency Modulation scheme brings optimized performance for applications with light output loading and low input voltages. The output ripple and noise are lower compared with the circuits operating in PSM mode. The PFM control circuit operating in 100KHz (max.) switching rate results in smaller passive components. The space saving SOT-89 and TO-92 packages make the AIC1639 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones. Provided with an external transistor driver pin (EXT), the AIC1639 is recommended for applications requiring current as large as several tens to several hundreds of milli-amperes. Guaranteed Start-Up from Below 0.9 V. High Efficiency. Low Quiescent Current. Few Number of External Components needed. Low Ripple and Low Noise. Fixed Output Voltage: 2.7, 3.0V, 3.3V, and 5V. Driver for External Transistor. Space Saving SOT-89 and TO-92 Packages. ¡½ l l l l l l APPLICATIONS Pagers. Cameras. Wireless Microphones. Pocket Organizers. Battery Backup Suppliers. Portable Instruments. ¡½ TYPICAL APPLI...