LM317G - UMW
Full Technical Specifications
14 Parameters| Parameter / Attribute | Specification / Value |
|---|---|
| Output type | Adjustable |
| Mounting | Surface Mount |
| Voltage - input | 40V |
| Voltage - output | 37V |
| Voltage - output (Min (Fixed)) | 1.2V |
| Output current | 1.5A |
| Current - quiescent | 12 mA |
| Operating temperature | 0°C ~ 125°C (TJ) |
| PSRR | 75dB ~ 60dB (120Hz) |
| Package | Tape & Reel (TR) Cut Tape (CT) |
| Case | TO-261-4, TO-261AA |
| Protection features | Over Current, Over Temperature, Short Circuit |
| Number of regulators | 1 |
| Output configuration | Positive |
Need Stock or a Drop-in Second-Source for LM317G?
Package: TO-220 / SOT-223 / TO-92 / DPAK · Pin-compatible replacements with immediate Shenzhen spot stock
The LM317 has been the default adjustable linear regulator since the 1970s and remains in continuous production across TI, ST, onsemi and a long clone list. The confusion is all in the suffix: LM317, LM317T, LM317L and LM317M are the same regulator design at different packages and current limits, and the modern surface-mount sockets are usually filled by SOT-223 clones such as the AMS317. Where a rail needs more than the 1.5A a TO-220 LM317 can pass, the family ladder (LM350 at 3A, LM338 at 5A) is the correct answer - with a lower output-voltage ceiling as the trade.
Verified Pin-Compatible Replacements (4 verified alternatives)
The Full-Current Package, Named
Shenzhen Spot Stock (24-48h Dispatch)
The TO-220 member of the family: 1.5A output at the full 1.2V to 37V adjustment range, reference 1.25V, adjustment pin current about 50uA.
Input up to 40V class (see the vendor datasheet for the exact maximum differential); output 1.25V to 37V set by the two-resistor divider.
Small Current, Small Body
Shenzhen Spot Stock (24-48h Dispatch)
The 100mA member: same 1.25V reference and adjustment behavior, but rated at a tenth of the TO-220 current.
Same 1.25V to 37V output range; input differential and dissipation limited by the tiny TO-92 body.
The SMD Socket Filler
Shenzhen Spot Stock (24-48h Dispatch)
The LM317-compatible adjustable regulator in SOT-223: same 1.25V reference and divider-based setting; current rating is package-limited (roughly 1A only with generous copper).
Same adjustment range; thermal behavior is the whole story - junction-to-ambient around 60 degC/W without a copper pour.
The Current Ladder Top (5A)
Shenzhen Spot Stock (24-48h Dispatch)
The 5A member of the adjustable family: same adjustment topology, higher current die - and a lower output ceiling (around 32V rather than 37V).
Output to about 32V; input differential limits per the datasheet; LM350 (3A) sits between this and the LM317.
Buyer & Quality Checklist for Sourcing Alternatives
- Decode the suffix before ordering: T = TO-220 (1.5A), L = TO-92 (100mA), M = mid-power TO-202 class (500mA), K = TO-3, D/S = DPAK/D2PAK, N or MP = SOT-223. Same regulator, different thermal envelopes.
- The LM317 output cannot go below its 1.25V reference without a negative rail below ground - designs wanting a true 0V-output supply need a different regulator, not a different LM317.
- SOT-223 clones (AMS317 and the Chinese fab family) are electrically compatible but package-limited: derate to roughly 1A and give the tab real copper or the part runs at its thermal wall.
- For currents above 1.5A go up the ladder (LM350 3A, LM338 5A) and re-check the reduced maximum output voltage; two parallel LM317s are not a substitute.
- The negative-rail complement for split supplies is the LM337, with mirrored pin order - never fit a positive part in the negative socket.
- The adjustment-pin current is small but not zero (about 50uA): for precision outputs use the datasheet-recommended resistor network and keep the adjustment pin bypassed.
Frequently Asked Technical Questions
Q: What is the difference between LM317 and LM317T?
A: Package only: LM317T is the TO-220 body, which is the form the 1.5A rating refers to. Electrically the die family is identical across suffixes - the differences to watch are current rating and thermal resistance of each package.
Q: Can an AMS317 (SOT-223) replace a TO-220 LM317?
A: Electrically yes, thermally not blindly: the SOT-223 part is package-limited to roughly 1A with good copper and far less without it. On loads that heated the TO-220, the SOT-223 swap needs a dissipation review first.
Q: How do I get more than 1.5A from an LM317 circuit?
A: Step up the family: LM350 for 3A, LM338 for 5A (both with a slightly lower output ceiling), each with the heatsinking the current demands. Paralleling LM317s does not work because the parts do not share current.