LP2975 Datasheet, PDF (1/37 Pages) National Semiconductor (TI) – MOSFET LDO Driver/Controller

LP2975
www.ti.com
SNVS006F – SEPTEMBER 1997 – REVISED APRIL 2013
MOSFET LDO Driver/Controller
Check for Samples: LP2975
FEATURES
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•2 Simple to Use, Few External Components
• Ultra-small VSSOP-8 Package
• 1.5% (A Grade) Precision Output Voltage
• Low-power Shutdown Input
• < 1 µA in Shutdown
• Low Operating Current (180 µA Typical @ V_IN =
5V)
• Wide Supply Voltage Range (1.8V to 24V)
• Built-in Current Limit Amplifier
• Overtemperature Protection
• 5.0V, and 3.3V Standard Output Voltages
• Can be Programmed Using External Divider
• −40°C to +125°C Junction Temperature Range
APPLICATIONS
• High-current 5V to 3.3V Regulator
• Post Regulator for Switching Converter
• Current-limited Switch
DESCRIPTION
A high-current LDO regulator is simple to design with
the LP2975 LDO Controller. Using an external P-FET,
the LP2975 will deliver an ultra low dropout regulator
with extremely low quiescent current.
High open loop gain assures excellent regulation and
ripple rejection performance.
The trimmed internal bandgap reference provides
precise output voltage over the entire operating
temperature range.
Dropout voltage is “user selectable” by sizing the
external FET: the minimum input-output voltage
required for operation is the maximum load current
multiplied by the R_DS(ON) of the FET.
Overcurrent protection of the external FET is easily
implemented by placing a sense resistor in series
with V_IN. The 57 mV detection threshold of the current
sense circuitry minimizes dropout voltage and power
dissipation in the resistor.
The standard product versions available provide
output voltages of 5.0V, or 3.3V with specified 25°C
accuracy of 1.5% (“A” grade) and 2.5% (standard
grade).
Block Diagram
*R_SET values are: 208k for 12V part, 72.8k for 5V part, and 39.9k for 3.3V part.
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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