CE8421

5A, 500KHz Synchronous Boost Converter with Output Disconnect CE8421 Series  INTRODUCTION: The CE8421 devices provide a power supply solution for products powered by either a one-cell Li-Ion or Li-polymer, or a two to three-cell alkaline, NiCd or NiMH battery. The converter generates a stable output voltage that is adjusted by an external resistor divider. It provides high efficient power conversion and is capable of delivering output currents up to 2.1A at 5V at a supply voltage down to 3V. The implemented boost converter is based on a fixed switching frequency (500kHz typical), current-mode controller using a synchronous rectifier to obtain maximum efficiency. Boost switch and rectifier switch are connected internally to provide the lowest leakage inductance and best EMI behavior possible. The current-mode control scheme provides fast transient response and good output voltage accuracy. At light load, the converter will automatically enter into Pulse Frequency Modulation (PFM) o...