The AP1601 is a high efficiency step-up DC/DC converter from Anachip Corp. It can be used with 1 to 4 NiMH battery cells and only requires three external components to deliver a fixed output voltage of 3.3V or 5V. The AP1601 starts up from less than 0.9V input with 1mA load. The Pulse Frequency Modulation scheme provides 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 MSOP packages make the AP1601 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones.