SG1577 Datasheet | Fairchild Semiconductor

Features - - - - - - - - - - - Integrated Two Sets of MOSFET Drivers Two Independent PWM Controllers Constant Frequency Operation: Free-running Fixed Frequency Oscillator Programmable: 60k Hz to 320k Hz Wide Range Input Supply Voltage: 8~15V Programmable Output as Low as 0.7V Internal Error Amplifier Reference Voltage: 0.7V±1.5% Two Soft-Start / EN Functions Programmable Over-Current Protection (OCP) 30V HIGH Voltage Pin for Bootstrap Voltage Output Over-Voltage Protection (OVP) SOP and DIP 20-pin Description The SG1577 is a high-efficiency, voltage-mode, dualchannel, synchronous DC/DC PWM controller for two independent outputs. The two channels are operated out of phase. The internal reference voltage is trimmed to 0.7V±1.5%. It is connected to the error amplifier’s positive terminal for voltage feedback regulation. The soft-start circuit ensures the output voltage can be gradually and smoothly increased from zero to its final regulated value. The soft-start pin can also be used for chip-enable function. When two soft-start pins are grounded, the chip is disabled and the total operation current can be reduced to under 0.55m A. The fixedfrequency is programmable from 60k Hz to 320k Hz. The Over-Current Protection (OCP) level can be programmed by an external current sense resistor. It has two integrated sets of internal MOSFET drivers. SG1577 is available in 20-pin SOP and DIP packages. Applications - - CPU and GPU Vcore Power Supply Power Supply Requiring Two Independent Outputs Ordering Information Part Number SG1577SZ SG1577SY .. SG1577DY . Operating Temperature Range -40°C to +85°C -40°C to +85°C -40°C to +85°C Package 20-Lead, Small Outline Package (SOP-20) 20-Lead, Small Outline Package (SOP-20) 20-Lead, Dual In-Line Package (DIP-20) Packing Method Tape & Reel Tape & Reel Tube © 2009 Fairchild Semiconductor Corporation SG1577 - Rev. 1.0.5 .fairchildsemi. - Dual Synchronous DC/DC Controller Application Diagram Figure 1. Typical Application Interna...