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Technology Compliant Energy
Management Unit
General Description
The LP5550 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 LP5550 contains an advanced, digitally controlled
switching regulator for supplying variable voltage to proces-
sor core and memory. The device also incorporates 3 pro-
grammable LDO-regulators for powering I/O, PLLs and
maintaining memory retention in shutdown-mode.
The device is controlled via the PWI open-standard inter-
face. The LP5550 operates cooperatively with PowerWise
technology compatible processors to optimize supply volt-
ages adaptively over process and temperature variations or
dynamically using frequency/voltage pre-characterized
look-up tables.
Features
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Supports high-efficiency PowerWise Technology
Adaptive Voltage Scaling
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PWI open standard interface for system power
management
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Digitally controlled intelligent voltage scaling
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1 MHz PWM switching frequency
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Auto or PWI controlled PFM mode transition
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Internal soft start/startup sequencing.
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3 programmable LDOs for I/O, PLL, and memory
retention supply generation.
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Power OK output.
Applications
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GSM/GPRS/EDGE & UMTS cellular handsets
Hand-held radios
PDAs
Battery powered devices
Portable instruments
System Diagram
20154563
FIGURE 1. System Diagram
漏 2005 National Semiconductor Corporation
DS201545
www.national.com