SC470
SC470 is Synchronous Buck Controller manufactured by SEMTECH.
Description
The SC470 is a single output, constant on-time synchronous-buck, pseudo-fixed frequency, PWM controller intended for use in notebook puters and other battery operated portable devices. Features include high efficiency and fast dynamic response with no minimum on-time. The excellent transient response means that SC470 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 RSENSE in source of low-side MOSFET for greater accuracy Resistor programmable on-time Cycle-by-cycle current limit Digital soft-start bined EN and PSAVE functions Over-voltage/under-voltage fault protection and PGD output 20% OVP threshold for simpler dynamic voltage transition circuitry 5µA typical shutdown current Low quiescent power dissipation 14 lead TSSOP and 16 pin MLPQ (4mm x 4mm) packages Industrial temperature range 0.85% DC accuracy Integrated gate drivers with soft-switching
The SC470 is specifically targeted for graphics processor power supplies that require dynamic voltage transition, with a tight 0.85% DC accuracy and a 20% OVP threshold. The 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 or input voltage. After the transient event, the controller frequency will return to steady state operation. At light loads, Power-Save Mode enables the SC470 to skip PWM pulses for better efficiency. The output voltage can be adjusted from 0.5V to VCCA. The integrated gate drivers feature adaptive shootthrough protection and soft switching. Additional Features include cycle-by-cycle current limit, digital soft-start, overvoltage and under-voltage protection, and a PGD output.
Applications
Graphics Cards Embedded...
