Verdict scale used on this site: Drop-in, Change values, New layout, Not recommended. Parts that could not be checked against an official datasheet are not listed.
Verdicts
| Candidate | Verdict | Conditions |
|---|---|---|
| TI LM1117 / LM1117I | Drop-in (conditions) | IOUT at or below 800 mA; use LM1117I below 0 °C; output cap at least 10 µF tantalum with ESR 0.3–22 Ω; 22 µF tantalum if you fit CADJ |
| ST LD1117 | Drop-in (conditions) | IOUT at or below 800 mA; use the C version below 0 °C (its ADJ specs are wider); θJA 110 °C/W versus 90, so redo the heat check |
| JSCJ CJT1117B | Drop-in (conditions) | VOUT at or below 5 V only (ADJ range 1.25–5 V); R1 at or below 170 Ω |
AMS1117 vs TI LM1117
| Item | AMS1117 | LM1117 | Result |
|---|---|---|---|
| SOT-223 pinout | 1 GND/ADJ, 2 VOUT, 3 VIN, tab VOUT | Same | Same |
| Rated current | 1 A (limit 900/1100/1500 mA) | 800 mA (limit 800/1200/1500 mA) | Use at or below 800 mA |
| Max VIN | 15 V | 15 V recommended, 20 V absolute maximum | OK |
| VREF | 1.232/1.250/1.268 V | 1.250 V typ; 1.225–1.270 V when VIN−VOUT is at or below 10 V | Slightly wider |
| Dropout (max) | 1.3 V at 0.8 A | 1.2/1.25/1.3 V at 100/500/800 mA | OK |
| Minimum load (max) | 10 mA | 5 mA | OK |
| IADJ | 55 µA typ | 60 typ / 120 µA max | Negligible shift |
| Output capacitor | 22 µF tantalum | At least 10 µF tantalum, ESR 0.3–22 Ω; 22 µF tantalum if you fit CADJ | Check ESR before using an MLCC |
| Tj range | −40 to 125 °C | 0 to 125 °C (LM1117I −40 to 125 °C) | Use LM1117I for cold |
| θJA SOT-223 | 90 °C/W | 61.6 °C/W | Different test boards |
AMS1117 vs ST LD1117
| Item | AMS1117 | LD1117 | Result |
|---|---|---|---|
| SOT-223 pinout | 1 GND/ADJ, 2 VOUT, 3 VIN, tab VOUT | Same | Same |
| Rated current | 1 A | 800 mA | Use at or below 800 mA |
| Max VIN | 15 V | 15 V (18 V if IOUT is below 20 mA) | Same |
| VREF | 1.232–1.268 V | 1.238/1.25/1.262 V at 25 °C; 1.225–1.275 V full range | Comparable |
| Dropout | 1.3 V max at 0.8 A | 1.1/1.15/1.2 V max at 100/500/800 mA | OK |
| Minimum load | 10 mA max | 2 typ / 5 mA max | OK |
| IADJ | 55 µA typ | 60 typ / 120 µA max | Negligible shift |
| Output capacitor | 22 µF tantalum | At least 10 µF | OK |
| Temperature | Tj −40 to 125 °C | 0 to 125 °C (C version −40 to 125 °C) | Use the C version for cold. Its ADJ specs are wider (Vref 1.2–1.3 V over the full range, dropout up to 1.3 V). |
| θJA SOT-223 | 90 °C/W | 110 °C/W (θJC 15 °C/W) | Runs hotter |
AMS1117 vs JSCJ CJT1117B
| Item | AMS1117 | CJT1117B | Result |
|---|---|---|---|
| SOT-223 pinout | 1 GND/ADJ, 2 VOUT, 3 VIN | 1 ADJ/GND, 2 OUTPUT, 3 IN | Same pins 1–3 |
| Rated current | 1 A | 1 A | Same |
| ADJ output range | not limited in the datasheet | 1.25–5 V | Not for outputs above 5 V |
| Max VIN | 15 V | 15 V recommended, 20 V absolute maximum | Same |
| Tj range | −40 to 125 °C | −40 to 125 °C | Same |
| Dropout | 1.3 V max at 0.8 A | 1.15 typ / 1.30 V max at 1 A | OK |
| IADJ | 55 µA typ | 60 typ / 120 µA max | Negligible shift |
| Minimum load | 10 mA max | 2 typ / 7 mA max | OK |
| R1 requirement | at or below 125 Ω (from min load) | at or below 170 Ω | 120 Ω fits both |
| θJA | 90 °C/W | 100 °C/W | Slightly hotter |
Heat at 5 V to 3.3 V, 0.5 A
P = 0.85 W. Test boards differ, so treat this as a rough comparison only.
| Part | θJA (°C/W) | Tj at Ta 25 °C | Tj at Ta 50 °C | Max current for Tj at or below 125 °C (25 °C / 50 °C) |
|---|---|---|---|---|
| AMS1117 | 90 | 101.5 °C | 126.5 °C (over) | 0.65 / 0.49 A |
| LM1117 | 61.6 | 77.4 °C | 102.4 °C | 0.96 A, capped at the 0.8 A rating / 0.72 A |
| LD1117 | 110 | 118.5 °C | 143.5 °C (over) | 0.54 / 0.40 A |
| CJT1117B | 100 | 110.0 °C | 135.0 °C (over) | 0.59 / 0.44 A |
Keeping the AMS1117 divider (R1 120 Ω, R2 196 Ω) gives 3.302 V on AMS1117 (IADJ 55 µA) and 3.303 V on LM1117 and LD1117 (IADJ 60 µA). The shift is about 1 mV at typical values.
If the original AMS1117 runs hot, a pin-compatible alternate will not fix it. LM1117’s lower θJA comes from a different test board. Add copper or use the LM2596-ADJ calculator when a buck is the right next step.
Pitfalls
- ADJ and fixed versions share a pinout, but on fixed parts pin 1 is GND.
- LM1117 requires output-capacitor ESR of 0.3–22 Ω. A very low-ESR ceramic can fall outside that.
- Standard LM1117 and LD1117 grades only go down to 0 °C. Outdoor products need the LM1117I or LD1117 C version.
- CJT1117B ADJ is limited to 5 V out. A 9 V or 12 V design needs a different part.
- This page only verifies the SOT-223 pinout. TO-252 is not the same footprint.
Part numbers
| Maker | Part | Package | Source |
|---|---|---|---|
| TI | LM1117MP-ADJ / LM1117IMP-ADJ (also MPX reel) | SOT-223 / DCY | SNOS412Q, checked 2026-10-26 |
| ST | LD1117STR (ADJ), LD1117SC-R (ADJ, C version) | SOT-223 | Rev 38 order codes |
| JSCJ | CJT1117B-ADJ | SOT-223 | Rev 2.3 ordering information |
Disclaimer
The comparisons use the manufacturer datasheets above as read on 26 Oct 2026. “Drop-in” means the listed pinout and parameters meet the AMS1117 values under the stated conditions. It is not a guarantee for every design. θJA values come from different test boards. Verify with the current datasheets and test the board before switching in production.
Updated: 2026-10-26 · Jasper
Verify against the datasheet before use.