General Description; Typical Application Circuits - Hyundai ImageQuest L70A Technical & Service Manual

L70A Technical Service Manual
LP3961/3964
MC68HC705BD7B
800mA Fast Ultra Low Dropout Linear Regulators

General Description

The LP3961/LP3964 series of fast ultra low-dropoutlinear
regulators operate from a +2.5V to +7.0V inputsupply . Wide
range of preset output voltage options are available. These
ultra low dropoutlinear regulators respond very fast to step
changes in load which makes them suitable for low voltage
microprocessor applications. The LP3961/LP3964 are de-
veloped on a CMOS process which allows low quiescent
current operation independent of output load current. This
CMOS process also allows the LP3961/LP3964 to operate
under extremely low dropoutconditions.
Dropout Voltage: Ultra low dropoutvoltage; typically24mV
at 80mA load current and 240mV at 800mA load current.
Ground Pin Current: Typically4mA at 800mA load current.
Shutdown Mode: Typically 15 A quiescent current when
the shutdown pin is pulled low .
Error Flag: Error flag goes low when the output voltage
drops 10% below nominal value (for LP3961).
SENSE: Sense pin improves regulation at remote loads.
(For LP3964)
Precision Output Voltage: Multipleoutput voltage options
are available ranging from 1.2V to 5.0V and adjustable, with
a guaranteed accuracy of
and
+/-
3.0% over all conditions ( varying line, load, and
tempera- ture).

Typical Application Circuits

# Minimumoutputcapacitance is 10 F to ensure stabilityover fullload current range. More capacitance provides superior dynamic performance and additional
stability margin.
*SD and ERROR pins must be pulledhigh througha 10kWpull-upresistor. Connect the ERROR pin to groundif this functionis not used. See applications sec-
tion for more information.
+/-
1.5% at room temperature,
Features
•
Ultra low dropoutvoltage
•
Low ground pin current
•
Load regulation of 0.02%
• 15 A quiescent current in shutdown mode
• Guaranteed output current of 0.8A DC
•
Available in SOT-223,T O-263 and TO-220 packages
•
Outputvoltage accuracy +/- 1.5%
• Error flag indicates output status (LP3961)
•
Sense option improves better load regulation (LP3964)
Extremely low output capacitor requirements
•
• Overtemperature/overcurrentprotection
• - 40!C to +125!C junction temperature range
Applications
• Microprocessor power supplies
• GTL, GTL+, BTL, and SSTL bus terminators
• Power supplies for DSPs
SCSI terminator
•
•
Post regulators
•
High efficiency linear regulators
• Battery chargers
•
Other battery powered applications
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DS101 129-1