AP1603

AP1603 Step-Up DC/DC Converter Features -A Guaranteed Start-Up from less than 0.9 V. -High Efficiency. -Low Quiescent Current. -Less Number of External Components needed. -Low Ripple and Low Noise. -Space Saving Pb-Free Packages: SOT23-6 General Description The AP1603 is a high efficiency step-up DC/DC converter for applications using 1 to 2 NiMH battery cells. Only three external components are required to deliver a fixed output voltage of 3.3V. The AP1603 starts up from less than 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 150KHz (max.) switching rate results in smaller passive components. The space saving SOT23-6 packages make the AP1603 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones. Applications -Pagers. -Cameras. -Wireless Microphones. -Pocket Organizers. -Battery Backup Suppliers. -Portable Instruments. Pin Assignments Pin Descriptions Description 1.2V Reference Voltage. Bypass with a 0.1µF REF capacitor. Power Output. OUT provides bootstrap power OUT to the IC. N-Channel and P-Channel Power MOSFET LX Drain GND Ground Shutdown Input. Drive high (>80% of VOUT) for operating mode. Drive low (