SC411 Datasheet | SEMTECH

Description The SC411 is a constant on-time synchronous buck PWM controller in a space-saving MLPQ package intended for use in notebook puters and other battery operated portable devices. Features include high efficiency and a fast dynamic response with no minimum on-time. The excellent transient response means that SC411 based solutions will require less output capacitance than peting fixed frequency converters. .. Features Constant on-time for fast dynamic response Programmable VOUT range = 0.5 - VCCA VBAT range = 1.8V - 25V DC current sense using low-side RDS(ON) Sensing or sense resistor Resistor programmable frequency Cycle-by-cycle current limit Digital soft-start Powersave option Over-voltage/under-voltage fault protection 10μA typical shutdown current Low quiescent power dissipation Power good indicator 1.2% reference Integrated gate drivers with soft switching Enable pin 16 pin MLPQ (4mm x 4mm) Output soft discharge upon shutdown The switching frequency is constant until a step-in load or line voltage occurs. During this time the pulse density and frequency will increase or decrease to counter the change in output or input voltage. After the transient event, the controller frequency will return to steady-state operation. At light loads, Powersave Mode enables the SC411 to skip PWM pulses for better efficiency. The output voltage can be adjusted from 0.5V to VCCA. A frequency setting resistor sets the on-time for the controller. The integrated gate drivers feature adaptive shoot-through protection and soft-switching. Additional Features include cycle-by-cycle current limit, digital soft-start, over-voltage and under-voltage protection, a Power Good output and soft discharge upon shutdown. Applications Notebook puters CPU/IO Supplies Handheld Terminals and PDAs LCD Monitors Network Power Supplies Typical Application Circuit VBAT 5VSUS 5VSUS VBAT R1 RTON1 D1 C1 0.1u F R2 10R U1 EN/PSV Q1 DH LX 12 11 10 9 R5 C2 10u...