EmbeddedRelated.com
    Parts    LM317 Family    LM317    LM317LZ
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.

Part of LM317 family » LM317

LM317 Family

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

Part Number PSRR Package Output I Temp Range Current - Quiescent (Iq) Output V Stock
LM317LZ (this part) 120Hz 3-226 100mA 0degC ~ 125degC 5 mA 1.2V 21,947
LM317BTG (onsemi) 120Hz 3-220 1.5A -40degC ~ 125degC 10 mA 1.2V 34,978
LM317KCS (Texas Instruments) 120Hz 3-220 1.5A 0degC ~ 125degC 10 mA 1.25V 4,256
LM317DCYR 120Hz 4-261 1.5A 0degC ~ 125degC 10 mA 1.25V 65,965
Also available as: LM317MDT-TR