LX1677

www.DataSheet4U.com LX1677 TM ® AMD64 Processor VRM Controller P RODUCTION D ATA S HEET DESCRIPTION KEY FEATURES ƒ High Current Biphase Operation ƒ Outputs As Low As 0.800V ƒ † Biphase LoadSHARETM ƒ ‡ Transient Correction Loop™ Reduces Required Capacitance ƒ Differential Amplifier For Remote Voltage Sensing ƒ Integrated High Current MOSFET Drivers ƒ 200KHz to 1MHz Frequency Operation ƒ Programmable Slew Rate Control For Start-Up Sequence and VID change ƒ VID Changes On The Fly ƒ Power Good Indicator ƒ Short Circuit Protection ƒ Output Over Voltage and Under Voltage Protection ƒ No current-sense resistors APPLICATIONS The LX1677 is a highly integrated VRM power supply controller IC featuring two PWM switching regulator stages. The two constant frequency voltage-mode PWM phases are configured as a single biphase high current output core supply. In biphase operation, the high current (>35A) output is generated by a LoadSHARETM† technique that balances the currents in the two phases. Power loss and noise, due to the ESR of the input capacitors, are minimized by operating the PWMs 180° out of phase. A synchronized Transient Correction Loop† provides exceptional control of the output droop and overshoot during very high di/dt load changes, the circuit can be configured for droop only, overshoot only or both. This architecture also minimizes capacitor requirements while maximizing regulator response. A true differential input amplifier is used for remote voltage sensing at the...