National Semiconductor LP3972 User Manual
User's Guide
SNVA235A – May 2007 – Revised April 2013
AN-1621 LP3972 USB Evaluation Board Rev B
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General Description
The LP3972 Flex PMU is a complete power management IC designed for advanced processors. It
contains 5 low noise low dropout regulators, 3 DC/DC buck converters, a backup battery charger, real
time clock supply regulator [RTC], 2 GPO’s and high speed I
2
C serial interface to program individual
regulator output voltages as well as offer on/off control. This USB evaluation board features independent
USB powering, virtual voltmeter bank all in a compact demonstration platform.
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Key Features
•
2.7V to 5.5V input voltage range
•
Programmable V
OUT
0.8 to 3.3 volts
•
Up to 95% efficiency
•
±3% output voltage accuracy
•
1.5A output current [bucks]
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Applications
•
Personal Media Players
•
Smart Phones
•
PDA Phones
•
Digital Cameras
4
Evaluation Board/Kit Overview
The LP3972 Evaluation Board supports complete functional evaluation of the power management IC. The
functions of the chip are controlled by the I
2
C interface. The I
2
C interface on the rev B and later USB
boards are driven via a COP8 microprocessor which supports a connection via the USB port and offers
chip powering and virtual software voltage measurement of all regulators. In addition, the LP3972 can be
powered directly through the USB port for full function. If high current Buck testing is desired, an external
LI ION cell or PS capable of supplying 2 amps or more will need to be connected to the appropriate
connector.
The evaluation board/kit consists of:
•
LP3972 Flex_PMU device soldered down in RSB-40 pin 5X5 WQFN package
•
Full USB interface
•
LED LDO monitoring with current limit resistors [selectable]
•
External power LDO, Buck output and main battery/supply connectors offered in heavy duty turret pins
and solder pads
•
Socket for back-up battery
•
Users guide
•
Codeloader Software version 1.2.0.2 or greater [may be sent via email]
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SNVA235A – May 2007 – Revised April 2013
AN-1621 LP3972 USB Evaluation Board Rev B
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