LM317
Encyclopedia
The LM317 is a popular variable voltage regulator
. It was invented by Robert C. Dobkin and Robert J. Widlar in 1970 while they worked at National Semiconductor
.
Voltage regulator
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components...
. It was invented by Robert C. Dobkin and Robert J. Widlar in 1970 while they worked at National Semiconductor
National Semiconductor
National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
.
Specifications
Vout range | 1.25 V 37 V |
Vin – Vout difference | 3 V 40 V |
Operation ambient temperature | 0℃ 125℃ |
Output Imax | less than 1.5 A (assuming factory-suggested heat sinking) |
Minimum Load Currentmax | 10 mA |
See also
- Bob PeaseBob PeaseRobert Allen Pease was an analog integrated circuit design expert and technical author. He designed several very successful "best-seller" integrated circuits, many of them in continuous production for multiple decades...
, designer of the LM331 and LM337, which are similar voltage references to the LM317 - Bandgap voltage referenceBandgap voltage referenceA bandgap voltage reference is a temperature independent voltage reference circuit widely used in integrated circuits, usually with an output voltage around 1.25 V, close to the theoretical 1.22 eV bandgap of silicon at 0 K. This circuit concept was first published by David Hilbiber in 1964...
- Brokaw bandgap referenceBrokaw bandgap referenceBrokaw bandgap reference is a voltage reference circuit widely used in integrated circuits, with an output voltage around 1.25 V with only little temperature dependence...
External links
- Information page about LM317 from National Semiconductor
- Datasheets
- ECE 327: LM317 Bandgap Voltage Reference Example – Brief explanation of the temperature-independent bandgap reference circuit within the LM317.
- The Design of Band-Gap Reference Circuits: Trials and Tribulations – Robert PeaseBob PeaseRobert Allen Pease was an analog integrated circuit design expert and technical author. He designed several very successful "best-seller" integrated circuits, many of them in continuous production for multiple decades...
, National SemiconductorNational SemiconductorNational Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
(shows LM317 design in Figure 4: LM117) - LM317 Circuit Schematics and Pinouts
- LM317 tutorial video with example circuits