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LM317LZ

LM317LZ

Various
Lower-power, small-package LM317 option for space-constrained designs needing an adjustable regulator.
Active21,947 in stock
Datasheet Digi-Key Mouser Compare Prices

Overview

The LM317LZ is an adjustable three-terminal positive voltage regulator capable of supplying up to 100mA over an output voltage range of 1.2V to 37V. This version of the classic LM317 architecture is housed in a compact TO-92 package, making it suitable for low-current applications where PCB space is limited. It includes internal thermal overload protection and short-circuit current limiting to ensure robust operation.

Why Choose This Part

The LM317LZ offers a wide input voltage range up to 40V and a simplified design process requiring no fixed voltage stocking. Its TO-92 footprint provides a much smaller alternative to TO-220 packages for 100mA loads, while internal safe-area compensation protects the device during startup or fault conditions.

Applications

Local On-Card Regulation
Providing a stable, adjustable voltage rail for sensitive analog or digital circuitry directly at the point of load.
Programmable Output Regulation
Configuring specific output voltages using only two external resistors for non-standard voltage rails.
Precision Current Limiter
Utilizing the 1.25V internal reference to create a constant current source for low-power LEDs or sensor biasing.
Floating High-Voltage Regulation
Operating the device in a floating mode to regulate high-voltage differentials as long as the input-to-output maximum is not exceeded.

Key Specifications

PSRR 80dB ~ 65dB (120Hz)
Output Type Adjustable
Mounting Type Through Hole
Package / Case TO-226-3, TO-92-3 (TO-226AA)
Current - Output 100mA
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-92-3
Current - Quiescent (Iq) 5 mA
Voltage - Output (Min/Fixed) 1.2V

Getting Started

To implement the LM317LZ, connect two external resistors to set the output voltage based on the 1.25V reference. Ensure a minimum 0.1uF disc or 1uF tantalum input capacitor if the device is far from the filter capacitors, and a 1uF tantalum or 25uF aluminum electrolytic output capacitor to improve transient response. Refer to the datasheet's typical application circuits for calculating the resistor divider values.

LM317 Family

Comparing specs that differ across variants. The current part is highlighted.

Part Number PSRR Package Output I Current - Quiescent (Iq) Output V Stock
LM317LZ (this part) 120Hz 3-226 100mA 5 mA 1.2V 21,947
LM317DCYR 120Hz 4-261 1.5A 10 mA 1.25V 65,965
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