SC4602A

High Efficiency Synchronous, Step Down Controller POWER MANAGEMENT Description The SC4602A/B is a voltage mode step down (buck) regulator controller that provides accurate high efficiency power conversion from an input supply range of 2.75V to 5.5V. A high level of integration reduces external component count and makes it suitable for low voltage applications where cost, size and efficiency are critical. The SC4602A/B drives external complementary power MOSFETs; P-channel on the high side and N-channel on www.DataSheet4U.com the low side. The use of high side P-channel MOSFET eliminates the need for an external charge pump and simplifies the high side gate driver. Non-overlap protection is provided for the gate drive signals to prevent shoot through of the MOSFET pair. Voltage drop across the Pchannel MOSFET during its conduction is sensed for lossless short circuit current limiting. A low power sleep mode can be achieved by forcing the SYNC/SLEEP pin below 0.8V. A synchronous mode of operation is activated as the SYNC/SLEEP pin is driven by an external clock. The quiescent supply current in sleep mode is typically lower than 10µA. A soft start (2.4ms for the SC4602A and 1.2ms for the SC4602B) is internally provided to prevent output voltage overshoot during startup. A 100% maximum duty cycle allows the SC4602A/B to operate as a low dropout regulator in the event of a low battery condition. The SC4602A/B has fixed switching frequency (300KHz for the SC4602A and 550KHz for the...