DESCRIPTION

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.

KEY FEATURES

◾ High Current Biphase Operation

◾ Outputs As Low As 0.800V

◾ † Biphase LoadSHARETM

◾ ‡ Transient Correction Loop™ Reduces Required Capacitance

◾ Differential Amplifier For Remote Voltage Sensing

◾ Integrated High Current MOSFET Drivers

◾ 200KHz to 1MHz Frequency Operation

◾ Programmable Slew Rate Control For Start-Up Sequence and VID change

◾ VID Changes On The Fly

◾ Power Good Indicator

◾ Short Circuit Protection

◾ Output Over Voltage and Under Voltage Protection

◾ No current-sense resistors

APPLICATIONS

◾ AMD Athlon 64™ and AMD Opteron™ Processors

◾ Processor Core Voltage Supply

◾ Voltage Regulator Modules