LX1676 Datasheet | Microsemi

TM ® Mobile AMD Athlon™ VRM Controller P RODUCTION D ATA S HEET DESCRIPTION KEY Features - High Current Biphase Operation - Outputs As Low As 0.925V - † Biphase Load SHARETM - † 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 The LX1676 is a highly integrated VRM power supply controller IC featuring two PWM switching ..net 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 (>25A) output is generated by a Load SHARETM† 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 processor core. A VID code generator provides an internal reference that will set the output voltage. This VID code can be changed during operation and the reference will slew the output voltage to its new setting at a preset rate. During VID changes on the fly the Power Good indication will stay valid. Current through the lower phase 1 MOSFET will be sampled using its RDS(ON) for current limit and shut down. For further protection, an over voltage circuit will trip at a specified setting...