Answer: Same-pinout (1 ADJ / 2 OUT / 3 IN, tab = OUT) 1.5 A replacements for a TO-220 LM317 are ST LM317 (LM317B for −40 °C), onsemi LM317TG / LM317BTG, JSCJ LM317 and HGSEMI LM317 / LM317A. All four share the 1.2–1.3 V reference and 40 V input-output limit. They differ on guaranteed current (JSCJ and HGSEMI: 1.0 A minimum vs 1.5 A), minimum load (JSCJ: 12 mA max) and temperature grade. TI LM317M is the 0.5 A same-pinout option.
Side-by-side datasheet values
Each row cites that manufacturer’s own PDF (page = PDF page order). No dropout values: TI, ST and onsemi give dropout only as typical curves, so this page uses TI’s recommendation of about 3 V headroom.
| Parameter | Value | Condition | Source |
|---|---|---|---|
| TI LM317 TO-220 (baseline) | 1 ADJUST / 2 OUTPUT, tab / 3 INPUT · Vref 1.2 / 1.25 / 1.3 V · IADJ 50 / 100 µA · min load 3.5 / 10 mA · current limit 1.5 min / 2.2 typ A (≤15 V) · VI−VO 40 V max · TJ 0–125 °C · RθJA 23.5 °C/W (KCS) | Orderable LM317KCS, NRND | TI SLVS044Z pp.5, 6, 7, 8; Addendum p.1 |
| ST LM317 | TO-220, TO-220FP, D²PAK, SOT223 · ADJUST / OUTPUT / INPUT, tab = OUTPUT · Vref 1.2 / 1.25 / 1.3 V · IADJ 50 / 100 µA · min load 3.5 / 10 mA · current limit 1.5 / 2.2 A (≤15 V), 0.4 A (40 V) · VI−VO 40 V | TOP: LM317 0–125 °C, LM317B −40 to 125 °C | ST DS0433 Rev 22 p.2 Fig.1; p.3 Table 1; pp.5–6 |
| ST LM317 thermal | RthJA TO-220 50 / D²PAK 62.5 / TO-220FP 60 / SOT223 110 °C/W; RthJC 5 / 3 / 5 / 15 °C/W | — | ST p.3 Table 2 |
| onsemi LM317 / LM317B | TO-220 (T) and D2PAK-3 (D2T) only · 1 Adjust / 2 Vout / 3 Vin, tab = pin 2 · Vref 1.2 / 1.25 / 1.3 V · IAdj 50 / 100 µA · min load 3.5 / 10 mA · Imax 1.5 / 2.2 A (≤15 V), 0.15 / 0.4 A (40 V) · θJA / θJC TO-220 65 / 5, D2PAK 70 / 5 °C/W | LM317TG TJ 0–125 °C; LM317BTG −40 to 125 °C (TO-220, 50/rail) | onsemi LM317/D Rev. 18 pp.1–2; p.10 Ordering |
| JSCJ LM317 (Rev 3.0) | SOT-223, TO-220-3L, TO-252-2L, TO-263-2L · 1 ADJ / 2 OUT / 3 IN · Vref 1.20 / 1.25 / 1.30 V (25 °C) · IADJ 46 / 100 µA · min load 3.5 / 12 mA · Imax 1.0 min / 2.2 typ A (≤15 V) · VI−VO 3.0–40 V · TJ −40 to 125 °C | Some codes marked NoRD — choose a Normal code | JSCJ LM317 Rev 3.0 pp.2, 3, 4, 6 |
| JSCJ LM317 thermal | RθJA SOT-223 100 / TO-220 66.7 / TO-252 80 / TO-263 62.5 °C/W | — | JSCJ p.5 |
| HGSEMI LM317 / LM317A (V1.4) | TO-220-3, TO-263-3, TO-263-2, TO-252-2, SOT-223 · 1 ADJUST / 2 VOUT / 3 Vin · Vref 1.20–1.30 V · IAdj 50 / 100 µA · min load 3.5 / 10 mA · Imax 1 min / 1.95 typ A (≤15 V, TO-220), 0.4 A (40 V) · VI−VO 40 V | TA: LM317 0–70 °C; LM317A −40 to 85 °C | HGSEMI LM317 V1.4 (Chinese) pp.1–3 |
| TI LM317M (0.5 A) | SOT-223 (DCY), TO-252 (KVU) · 1 ADJ / 2 OUT / 3 IN · IO 0.01–0.5 A · VI−VO 2.5–37 V recommended, 40 V max · Vref 1.2 / 1.25 / 1.3 V · min load legacy 3.5 / 10 mA · TJ −40 to 125 °C | Legacy and new chip differ (IADJ, min load, RθJA) | TI SLVS297R pp.3–5 |
Which one to pick
| Need | Candidates | Watch |
|---|---|---|
| Same TO-220, 0 to 125 °C, 1.5 A guaranteed | ST LM317, onsemi LM317TG | onsemi makes only TO-220 and D2PAK-3, no SOT-223 |
| −40 °C | ST LM317B, onsemi LM317BTG, JSCJ LM317 (TJ −40 to 125 °C), HGSEMI LM317A (TA −40 to 85 °C) | HGSEMI’s plain LM317 is 0 to 70 °C only |
| Domestic (China) source | JSCJ LM317, HGSEMI LM317 / LM317A | Guaranteed current only 1.0 A min; JSCJ min load up to 12 mA |
| SOT-223 at 0.5 A or less | TI LM317M | Recommended VI−VO tops out at 37 V, not 40 V |
Pin order: same on all four
TI, ST, onsemi, JSCJ and HGSEMI all put ADJUST, OUTPUT, INPUT in the same order in TO-220/TO-263/SOT-223, with the tab on OUTPUT.
- TI p.5, onsemi p.1, JSCJ p.3 and HGSEMI p.2 number the pins 1/2/3.
- ST’s pin drawing (p.2 Fig.1) carries no numbers, but the physical order is the same.
- One ST EC-table line, “Reference voltage (between pin 3 and pin 1)” (p.6–7), doesn’t match the drawing. Use the drawing.
The differences that break designs
1. Guaranteed current. TI, ST and onsemi guarantee 1.5 A minimum current limit at VI−VO ≤ 15 V. JSCJ (p.6) and HGSEMI (p.3) guarantee only 1.0 A minimum (2.2 A and 1.95 A typical). If your design draws 1.2 A, only the first three are covered by the datasheet.
2. Minimum load. The usual 240 Ω R1 draws 1.25 V / 240 Ω = 5.2 mA.
| Part | Min-load max | R1 that covers it alone |
|---|---|---|
| TI / ST / onsemi / HGSEMI | 10 mA | ≤ 125 Ω |
| JSCJ | 12 mA | ≤ 104 Ω |
(TI p.8, ST pp.5–6, onsemi p.2, HGSEMI p.3, JSCJ p.6.) With no external load, a JSCJ part on a 240 Ω divider is outside its guarantee.
3. Thermal numbers are not comparable one-to-one. For the same 2 W in free air:
| Part | TO-220 RθJA | Junction rise at 2 W |
|---|---|---|
| TI (KCS) | 23.5 °C/W | +47 °C |
| ST | 50 °C/W | +100 °C |
| onsemi | 65 °C/W | +130 °C |
| JSCJ | 66.7 °C/W | +133 °C |
(TI p.7, ST p.3, onsemi p.2, JSCJ p.5.) The makers measure under different conditions; TI’s figure is a JEDEC board metric. Size the heat sink from the datasheet of the part you actually buy, using θHA ≤ RθJA − (θCH + RθJC) as in TI Equation 12 (p.24).
4. Headroom, not dropout. None of TI, ST or onsemi guarantees a dropout voltage; they show only typical curves. TI recommends about 3 V headroom (VI − VO) for full current (TI pp.13–14). Design every candidate to that figure.
Not drop-in, even though they look like it
- LM317L (100 mA, TO-92): the TO-92 lead order is not the same across makers. TI’s LM317L table lists INPUT, OUTPUT, ADJ (SLCS144G p.3). UTC’s LM317L lists ADJ, OUTPUT, INPUT (QW-R101-008.N p.1), the reverse. Check the drawing for the exact part. TI’s recommended range is 2.5–100 mA (p.4).
- LM1117-ADJ / AMS1117-ADJ: the SOT-223 pin order (ADJ, OUTPUT, INPUT) matches the LM317, but VIN is limited to 15 V (TI LM1117: 15 V recommended, 20 V absolute; AMS1117: 15 V), and TI LM1117 is an 800 mA part (TI SNOS412Q pp.3–6; AMS DS1117 pp.1–2). They cannot replace an LM317 running from 24 V. See AMS1117-ADJ and LM1117MP-ADJ.
- UTC LM317: rated “output current in excess of 1 A” (QW-R101-009.V p.1), not 1.5 A. Its EC table gives IO(MAX) only at 40 V (0.2 / 0.3 A, p.3).
Common mistakes
- Assuming every “LM317” is 1.5 A. Two domestic sources guarantee 1.0 A, and UTC is a 1 A part.
- Keeping R1 = 240 Ω with no load. It is below every maker’s 10–12 mA worst case.
- Copying TI’s 23.5 °C/W into a heat-sink calculation for another brand.
- Ordering HGSEMI plain LM317 for an outdoor design. It is 0 to 70 °C; LM317A is the −40 °C grade.
- Replacing a SOT-223 LM317 with an AMS1117-ADJ because the pins match. The input limit is 15 V.
- Picking a JSCJ code marked NoRD. Use a Normal-status code (JSCJ p.2).
Related pages
- LM317 in TO-220 datasheet notes
- Linear voltage regulators
- AMS1117-ADJ alternatives
- Power calculator for the PD sum
FAQ
- What can replace an LM317T? ST LM317, onsemi LM317TG (LM317BTG for −40 °C), JSCJ LM317 and HGSEMI LM317/LM317A use the same ADJ/OUT/IN TO-220 pinout.
- Are Chinese LM317 parts the same as TI? Pinout and reference match, but JSCJ and HGSEMI guarantee only 1.0 A minimum current and JSCJ’s minimum load is up to 12 mA.
- Can I use LM317L instead of LM317? Only up to 100 mA, and its TO-92 lead order differs between makers; check the drawing.
- Can AMS1117-ADJ replace LM317? Only if VIN stays at or below 15 V; the SOT-223 pin order matches, but the input limit does not.
- What is the LM317 dropout voltage? No maker in this comparison guarantees one; TI recommends about 3 V headroom.
- Is LM317M pin-compatible with LM317? Yes in SOT-223/TO-252 (1 ADJ, 2 OUT, 3 IN), but it is a 0.5 A part with 37 V recommended VI−VO.
Related (internal links)
- LM317 in TO-220 datasheet notes
- Linear voltage regulators
- AMS1117-ADJ
- LM1117MP-ADJ
- AMS1117-ADJ alternatives
- Power calculator
Sources (retrieved 2026-10-26)
- Texas Instruments, LM317 3-Pin Adjustable Regulator, SLVS044Z: https://www.ti.com/lit/ds/symlink/lm317.pdf
- STMicroelectronics, LM217/LM317 datasheet, DS0433 Rev 22 (Dec 2021): https://www.st.com/resource/en/datasheet/lm317.pdf
- onsemi, LM317/NCV317 datasheet, LM317/D Rev. 18 (Sept 2026): https://www.onsemi.com/pdf/datasheet/lm317-d.pdf
- JSCJ (Jiangsu Changjing), LM317 datasheet Rev 3.0 (July 2022): https://www.jscj-elec.com/gallery/file/LM317%20Rev-3.0.pdf
- HGSEMI, LM317 datasheet V1.4 (Dec 2025, Chinese): https://www.hgsemi.com.cn/upload/202601/%E5%8D%8E%E5%86%A0LM317%28%E4%B8%AD%E6%96%87%29%20202512.pdf (product page: https://www.hgsemi.com.cn/en/goods/list-141.html)
- Texas Instruments, LM317M datasheet, SLVS297R (May 2026): https://www.ti.com/lit/ds/symlink/lm317m.pdf
- Texas Instruments, LM317L datasheet, SLCS144G (Aug 2026): https://www.ti.com/lit/ds/symlink/lm317l.pdf
- Unisonic (UTC), LM317L datasheet, QW-R101-008.N (UTC website)
- Unisonic (UTC), LM317 datasheet, QW-R101-009.V: https://www.unisonic.com.tw/uploadfiles/836/part_no_pdf/LM317.pdf
- Texas Instruments, LM1117 datasheet, SNOS412Q: https://www.ti.com/lit/ds/symlink/lm1117.pdf
- Advanced Monolithic Systems, AMS1117 1A Low Dropout Voltage Regulator (DS1117; no revision code printed): http://www.advanced-monolithic.com/pdf/ds1117.pdf (page numbers are PDF page order). Checked against a mirror copy of this PDF (sha256 189a2651…a3f0); AMS prints no revision code, so we cannot prove it is the newest issue.
Disclaimer
Every value is copied from the named manufacturer’s datasheet, read on 26 Oct 2026; none come from distributor listings. “Same pinout” is not a qualification; check the exact ordering code, its lifecycle status and the thermal design against the datasheet of the part you buy.
Reviewed by: Jasper · Updated: 2026-10-26
Verify against the datasheet before use.