LX1676-CPW

LX1676 INTEGRATED PRODUCTS Mobile AMD Athlon™ VRM Controller P RELIMINARY D ATA S HEET DESCRIPTION KEY FEATURES High Current Biphase Operation Outputs As Low As 0.925V † 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 The LX1676 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 (>25A) 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 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 and clamp the output by turning off the upper MOSFETs and turning on the lower MOSFETs. The upper MOSFET drivers will use a bootstrap capacitor to provide the upper drive voltage over the input voltage range of 6 to 24 volts. WWW . Microsemi . C OM IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com † Patent numbers US6292378,US6285571,US6356063, US6605931 AMD Mobile Athlon™ or Duron™ Processor Core Voltage Supply Voltage Regulator Modules PRODUCT HIGHLIGHT T r a n s ie n t C o r r e c tio n L o o p V in + 5 V V in 6 to 2 4 V 70nH 5 B it V ID LX1676 V in 6 to 2 4 V Vout LX1676 LX1676 PACKAGE ORDER INFO TJ (°C) 0 to 70 PW 38-Pin Plastic TSSOP LQ 38-Pin Plastic MLPQ LX1676-CPW LX1676-CLQ Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1676-CLQTR) Copyright © 2000 Revision: 0.4b, 9/14/2004 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1676 INTEGRATED PRODUCTS Mobile AMD Athlon™ VRM Controller P RELIMINARY D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT WWW . Microsemi . C OM Supply Input Voltage (VCCL, VCC)................................................-0.3V to 6.0V Battery Input Voltage (VIN) ..............................................................-0.3V to 36V Current Limit Sense (ILIM1, ILIM3) ................................................-0.3V to 36V Topside Driver Supply Input Voltage (VC1, VC2, VC3)........ -0.3 toVSx + 6.0V Topside Driver Return Input Voltage (VS1, VS2)................................-5V to 36V Differential Sense Input Voltage (FB+, FB-)....................................-0.3V to 6.0V VID0 – VID4, Input Voltage ...............................................................-0.3V to 6V High Side Driver Peak (