LP5551SQXNOPB;LP5551SQNOPB;中文规格书,Datasheet资料.pdf

LP5551 LP5551 PowerWise Technology Compliant Energy Management Unit Literature Number: SNVS417A / December 2006 LP5551 PowerWise? Technology Compliant Energy Management Unit General Description The LP5551 is a PWI 1.0 compliant Energy Management System for reducing power consumption of stand-alone mo- bile phone processors such as base-band or applications processors. The LP5551 contains two advanced, digitally controlled switching regulators for supplying variable voltage to proces- sor core and memory. Two regulators provide P- and N- well biasing for threshold scaling applications. The device also in- tegrates 4 programmable LDO-regulators for powering I/O, PLLs and maintaining memory retention in shutdown-mode. The device is controlled via the PWI open-standard interface. The LP5551 operates cooperatively with PowerWise? tech- nology compatible processors to optimize supply voltages adaptively over process and temperature variations or dy- namically using frequency/voltage pre-characterized look-up tables and provides P- and N-well biasing for threshold scal- ing. Features ■ 2 300 mA buck regulators operate 180 degrees out of phase for reduced EMI ■ 1 MHz PWM switching frequency ■ 4 programmable LDOs ideal for I/O (two of these), PLL, and memory retention supply generation. ■ Supports high-efficiency PowerWise Technology Adaptive Voltage Scaling ■ PWI open standard interface for system power management ■ Digitally controlled intelligent voltage scaling ■ Auto or PWI controlled PFM mode transition ■ Internal soft start/startup sequencing. ■ Adjustable P- and N- well bias supply for threshold scaling ■ Power OK output. Applications ■ Dual core processors ■ GSM/GPRS/EDGE UMTS cellular handsets ■ Hand-held radios ■ PDAs ■ Battery powered devices ■ Portable instruments System DiagramFIGURE 1. System Diagram ? 2007 National Semiconductor Corporation 201721 L P 5 5 5 1 P o w e rW is e ? T e c h n o lo g y C o m p lia n t E n e rg y M a n a g e m e n t U