SC412A

SC412A Synchronous Buck Controller POWER MANAGEMENT Description The SC412A is a versatile, constant on-time synchronous buck, pseudo fixed-frequency, PWM controller intended for notebook computers and other battery operated portable devices. The SC412A contains all the features needed to provide cost-effective control of switch-mode power outputs. The output voltage is programmable from 0.75 to 5.25 external resistors. Switching frequency is internally preset to 325kHz. Additional features cycleby-cycle current limit, voltage soft-start, under-voltage protection, programmable over-current protection, soft shutdown, automatic power save and non-overlapping gate drive. The SC412A also provides an enable input and a power good output. Features ‹ VBAT Range 3V to 25V ‹ Soft-Shutoff at Output ‹ Current Sense Using Low-Side RDS(ON) or Resistor ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ † www.DataSheet4U.com volts using The constant on-time topology provides fast, dynamic response. The excellent transient response means that SC412A based solutions require less output capacitance than competing fixed-frequency converters. Switching frequency is constant until a step in load or line voltage occurs, at which time the pulse density and frequency will increase or decrease to counter the change in output voltage. After the transient event, the controller frequency returns to steady state operation. At light loads, the automatic power save mode reduces the switching frequency for improved efficiency. Se...