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LM317T-DG

LM317T-DG

STMicroelectronics
Linear Voltage Regulator IC Positive Adjustable 1 Output 1.5A TO-220
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Overview

The LM317T-DG is a monolithic integrated circuit in a TO-220 package intended for use as a positive adjustable voltage regulator. It is designed to supply up to 1.5A of load current with an output voltage adjustable over a 1.2V to 37V range. This regulator is exceptionally easy to use and requires only two external resistors to set the output voltage.

Why Choose This Part

The device features internal current limiting, thermal shutdown, and safe area compensation, making it essentially blow-out proof. It offers a high ripple rejection of up to 80dB at 120Hz and maintains 1% line and load regulation.

Applications

Adjustable Bench Power Supplies
Utilized as the primary regulation stage for variable DC power supplies due to its wide output range.
Local On-Card Regulation
Eliminates the noise and distribution problems associated with single-point regulation by providing stable power locally on a PCB.
Programmable Output Regulation
Can be configured with digital potentiometers or DACs to create a software-controlled variable voltage source.
Constant Current Regulators
Configured as a precision current limiter for charging batteries or driving high-power LED strings.

Key Specifications

PSRR 80dB ~ 65dB (120Hz)
Output Type Adjustable
Mounting Type Through Hole
Package / Case TO-220-3
Current - Output 1.5A
Protection Features Over Current, Over Temperature, Short Circuit
Number of Regulators 1
Output Configuration Positive
Operating Temperature 0degC ~ 125degC
Voltage - Input (Max) 40V
Voltage - Output (Max) 37V
Supplier Device Package TO-220
Current - Quiescent (Iq) 10 mA
Voltage - Output (Min/Fixed) 1.2V

Getting Started

To implement the LM317T-DG, connect a resistor between the VO and ADJ pins, and a second resistor (or potentiometer) from ADJ to ground. Ensure a minimum load current of 10mA for proper regulation and add a 0.1uF disc tantalum capacitor on the input if the device is far from the filter capacitors.

LM317T Family

Also available as: LM317T

Also Consider

LM317AT TITexas Instruments - Provides tighter output voltage tolerance and better line regulation for precision applications.
LM337T TITexas Instruments - The negative voltage complement to the LM317, useful for creating split-rail bipolar power supplies.
LD1085V STMicroelectronics - A Low Dropout (LDO) alternative that supports higher load currents up to 3A.