AP1603 (User Guide) STEP-UP DC/DC CONVERTER 1 Introduction AP1603 is a high efficiency step-up DC/DC converter for applications using as few as a single Ni-MH or Li-Ion battery cells. Only four 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 SOT26 packages make the AP1603 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones. 2 EVM Schematic (VIN=1.1 to 3.6V；VOUT=3.3V) AP34063 Rev. 1 1 of 2 www.diodes.com May 2009 © Diodes Incorporated AP1603 (User Guide) STEP-UP DC/DC CONVERTER 3 Board Layout Top Side 4 Bottom Side Bill of Materials (VOUT=3.3V) Component QTY Specification Maker Maker Part No. Size C1,C5 2 47uF/10V(MLCC) TAIYO YUDEN LMK325BJ476MM 1210 C2 - Open - - - C3 1 0.1uF/50V(MLCC) TAIYO YUDEN LMK212B7104KG 0805 C4 - Option - - - R1 - Open - - - R2 - Open - - - R3 - Open - - - L1 1 22uH/0.65A Wϋrth Electronics - U1 1 AP1603 DIODES Inc. AP1603WL-7 Location AP34063 Rev. 1 2 of 2 www.diodes.com SOT26-3L May 2009 © Diodes Incorporated