Answer: The closest SOT-23 drop-ins for TI TL431CDBZR (2 %, cathode-ref-anode = pins 1-2-3, 0–70 °C) are ST TL431CL3T / TL431ACL3T / TL431BL3T, SGMICRO SGM431XN3LG/TR (1 %) and 3PEAK TPR431B-S3TR (0.5 %, 80 mA max). onsemi TL431A/B is electrically similar but has no SOT-23. “TL431” in SOT-23 is sold with both K/R/A and R/K/A pin orders, so check the pinout against the exact ordering code before you swap.
Side-by-side datasheet values
Each row cites the manufacturer’s own PDF (page = PDF page order). Tolerances are written as percentages because the grade letters mean different things at different makers.
| Parameter | Value | Condition | Source |
|---|---|---|---|
| TI TL431CDBZR (baseline) | SOT-23-3: 1 K / 2 REF / 3 A · Vref 2.440 / 2.495 / 2.550 V (2 %) · IKA 1–100 mA · Imin 0.4 / 1 mA · | ZKA | 0.2 / 0.5 Ω · 0–70 °C · RθJA 206 °C/W |
| ST TL431 SOT23-3 | 1 Cathode / 2 Ref / 3 Anode (same as TI DBZ) · C 2 % (2.44 / 2.495 / 2.55 V), A 1 % (2.47 / 2.495 / 2.52 V), B 0.5 % (2.483 / 2.495 / 2.507 V) · Ik 1–100 mA · Imin C 0.5 / 1 mA · ZKA 0.22 / 0.5 Ω | Order codes TL431CL3T (2 %, 0–70 °C), TL431ACL3T (1 %, 0–70 °C), TL431BL3T (0.5 %, −40 to 125 °C) | ST DocID4467 Rev 17 p.3 Fig.3; p.4 Table 1; pp.5–6 Tables 3–4; p.19 Table 13 |
| ST TL431 temperature grades | C 0 to 70 °C; I −40 to 105 °C (TI I grade: −40 to 85 °C); IY −40 to 125 °C | — | ST p.4; TI p.5 §6.4 |
| ST TL431 SOT23-3 thermal | Rthja 248 °C/W | — | ST p.4 Table 1 |
| SGMICRO SGM431 / SGM431B | SOT-23: 1 CATHODE / 2 REF / 3 ANODE · SGM431 1 % (2.475 / 2.500 / 2.525 V), SGM431B 0.5 % (2.488 / 2.500 / 2.512 V) · IKA 1–100 mA · Imin 0.4 / 0.7 mA · | ZKA | 0.1 / 0.5 Ω · −40 to 125 °C |
| SGM431 limits / thermal | VKA absolute max 40 V (recommended Vref to 36 V); θJA 245 °C/W (SOT-23) | — | SGM431 Rev. B p.3 |
| 3PEAK TPR431B | SOT23G-3: 1 CATHODE / 2 REF / 3 ANODE · 0.5 % only (2.483 / 2.495 / 2.507 V) · IKA 1–80 mA · Imin 0.4 / 1 mA · | ZKA | 0.2 typ (no max) · −40 to 125 °C · θJA 400 °C/W |
| onsemi TL431A / TL431B | TO-92, SOIC-8, PDIP-8, Micro8 — no SOT-23 · A 1 % (2.47 / 2.495 / 2.52 V); B 0.4 % (2.485 / 2.495 / 2.505 V) · IK 1.0–100 mA · Imin 0.5 / 1.0 mA | SOIC-8: 1 Cathode, 8 Ref, 2/3/6/7 Anode (same as TI D) | onsemi TL431/D Rev. 45 pp.1–4 |
Check the pinout against the ordering code
TI’s DBZ package (the “DBZR” in TL431CDBZR is that package on tape and reel) is pin 1 cathode, pin 2 REF, pin 3 anode (K/R/A, TI p.4).
The trap: many parts called “TL431” in SOT-23 use R/K/A instead. Swap one in and the reference input lands on the cathode pad; the circuit won’t regulate. Check the pinout against the exact ordering code every time, not against the part family name.
| Part / ordering code | SOT-23 pin 1 / 2 / 3 | Same as TL431CDBZR? | Source |
|---|---|---|---|
| TI TL431 DBZ | K / REF / A | — (baseline) | TI p.4 |
| ST TL431xL3T | Cathode / Ref / Anode | Yes | ST p.3 |
| SGMICRO SGM431(B)XN3LG/TR | CATHODE / REF / ANODE | Yes | SGM431 p.4 |
| 3PEAK TPR431B-S3TR | CATHODE / REF / ANODE | Yes | TPR431 p.4 |
Pin-swapped (R/K/A) parts are listed under Don’t confuse with and Risk notes below. For TO-92 versions we deliberately list pin names only: makers number the leads in different directions, so check the drawing in the datasheet for your exact part.
Picking a replacement
- Need the same 2 % grade, 0–70 °C, same footprint: ST TL431CL3T is the closest match (Vref limits identical). If your BOM also lists the 1 % TI TL431ACDBZR, ST TL431ACL3T has the same 1 % limits.
- Need −40 °C or better tolerance: SGM431XN3LG/TR (1 %) and SGM431BXN3LG/TR (0.5 %) are both −40 to 125 °C. Their typical Vref is 2.500 V, not 2.495 V. That is inside a 2 % budget, but don’t call it “identical”.
- Need 0.5 %: TPR431B-S3TR or ST TL431BL3T. TPR431B is rated for only 80 mA of cathode current (TI: 100 mA) and has θJA 400 °C/W.
- Through-hole or SOIC-8: onsemi TL431A/B works electrically, but it has no SOT-23 option. Its B grade is 0.4 %, tighter than TI’s 0.5 % B grade. The datasheet notes that some onsemi ordering codes are discontinued (p.1), so check the status.
Worked example: same circuit, different heat
A TL431 shunt sinking 20 mA at VKA = 5 V dissipates 0.1 W. The junction rise above ambient, by package:
| Part | θJA / RθJA | Rise at 0.1 W |
|---|---|---|
| TI DBZ | 206 °C/W | +20.6 °C |
| SGM431 SOT-23 | 245 °C/W | +24.5 °C |
| ST SOT23-3 | 248 °C/W | +24.8 °C |
| 3PEAK SOT23G-3 | 400 °C/W | +40 °C |
(TI p.5, SGM431 p.3, ST p.4, TPR431 p.5.) JEDEC-board figures, not your PCB. A design sized close to the TI limit needs a re-check on TPR431B.
Don’t confuse with
- TI TL432 (and ST TL432xL3T, 3PEAK TPR432): electrically the same as TL431, but the SOT-23 pin order is REF/K/A (TI p.1, p.4; ST p.3; TPR431 p.4). It is not a drop-in replacement for TL431CDBZR; see our TL432ACDBZR notes.
- TI LMV431 (Vref 1.24 V; cathode up to 30 V recommended, 35 V absolute; 0.1–15 mA) and Diodes AZ431L (Vref 1.240 V; VKA up to 18 V recommended, 20 V absolute) are low-voltage shunts. With a 1.24 V reference the divider must be recalculated: a TL431 divider set for 5 V would give about 2.5 V. (LMV431 SNVS041G p.1, §7.1, §7.3; AZ431L DS36801 pp.4–5.)
Risk notes: parts we do not recommend as drop-ins
- UTC TL431 (SOT-23): pin order depends on the suffix. TL431G-AE3/AE2 are R/K/A; only the TL431NSG-AE3/AE2/AH3 versions are K/R/A. UTC’s “A” grade is 0.5 %, whereas TI’s “A” grade is 1 % (UTC QW-R103-003.AS pp.1, 4).
- Diodes TL431/TL432: the datasheet header says “Not recommended for new design – use AS431/AS431H” (DS35050 p.1).
- Diodes AZ431-A (SOT23): pin order is REF/CATHODE/ANODE (like a TL432), and Vref is 2.500 V typical (DS36721 pp.1, 5).
- onsemi KA431S/SA/SL: the same name ships in two SOT23 pin orders (MF: K/R/A; MF2: R/K/A), and the operating range is only −25 to +85 °C (KA431SL/D pp.1–2).
Common mistakes
- Ordering by family name (“TL431 SOT-23”) instead of ordering code. Pin order differs by maker and even by suffix.
- Comparing grades by letter. “A” is 1 % at TI and ST, but not at every maker (see the risk notes), and onsemi’s B is 0.4 % against TI’s 0.5 %. Compare percentages.
- Assuming 100 mA everywhere. TPR431 stops at 80 mA.
- Reusing a TL431 divider on a 1.24 V shunt. The output halves (see Don’t confuse with).
- Ignoring temperature grade. ST’s I grade is −40 to 105 °C, TI’s is −40 to 85 °C. Both are fine for a 0–70 °C C-grade socket, but read the right column.
Related pages
FAQ
- What can replace TL431CDBZR? ST TL431CL3T (same 2 % limits, same K/R/A SOT-23), SGM431XN3LG/TR (1 %, −40 to 125 °C) or TPR431B-S3TR (0.5 %, 80 mA max).
- Is ST TL431BL3T a 0.5 % part? Yes: ST lists TL431BL3T as 0.5 %, −40 to 125 °C, SOT23-3 (Table 13, p.19).
- Do all SOT-23 TL431 parts have the same pinout? No. Both K/R/A and R/K/A exist, sometimes under the same family name, so check the pinout against the ordering code.
- Is SGM431 Vref the same as TL431? Typical Vref is 2.500 V versus 2.495 V for TI; both sit within the stated 1 % or 2 % limits.
- Does onsemi make a SOT-23 TL431? Not in TL431/D Rev. 45: it lists TO-92, SOIC-8, PDIP-8 and Micro8 only.
- How much hotter does a TPR431B run? At the same 0.1 W, about +40 °C rise versus +20.6 °C for TI DBZ (JEDEC θJA 400 vs 206 °C/W).
Related (internal links)
Sources (retrieved 2026-10-26)
- Texas Instruments, TL431/TL432 Precision Programmable Reference, SLVS543S: https://www.ti.com/lit/ds/symlink/tl431.pdf
- STMicroelectronics, TL431/TL432 datasheet, DocID4467 Rev 17 (Sept 2022): https://www.st.com/resource/en/datasheet/tl431.pdf
- onsemi, TL431A, B Series / NCV431 datasheet, TL431/D Rev. 45 (Nov 2025): https://www.onsemi.com/pdf/datasheet/tl431-d.pdf
- SGMICRO, SGM431/SGM431B datasheet, Rev. B (Sept 2024): https://www.sg-micro.com/rect/assets/1d9dd353-f533-43b7-82a3-bad00babafda/SGM431.pdf
- 3PEAK, TPR431/TPR432 datasheet, Rev. A.2 (June 2024): https://static.3peak.com/res/doc/ds/Datasheet_TPR431-TPR432.pdf
- Unisonic (UTC), TL431 datasheet, QW-R103-003.AS: https://www.unisonic.com.tw/uploadfiles/836/part_no_pdf/tl431.pdf
- Diodes Incorporated, TL431/TL432 datasheet, DS35050 Rev. 7-3: https://www.diodes.com/assets/Datasheets/TL431_432.pdf
- Diodes Incorporated, AZ431-A datasheet, DS36721 Rev. 6-2: https://www.diodes.com/assets/Datasheets/AZ431A.pdf
- onsemi, KA431S/SA/SL datasheet, KA431SL/D Rev. 9: https://www.onsemi.com/pdf/datasheet/ka431sl-d.pdf
- Texas Instruments, LMV431 datasheet, SNVS041G: https://www.ti.com/lit/ds/symlink/lmv431.pdf
- Diodes Incorporated, AZ431L datasheet, DS36801 Rev. 5-2: https://www.diodes.com/assets/Datasheets/AZ431L.pdf
Disclaimer
Every value is copied from the named manufacturer’s datasheet, read on 26 Oct 2026; none come from distributor listings. “Drop-in” here means the same SOT-23 pin order and overlapping Vref, current and temperature ratings. It is not a qualification. Check lifecycle status and the exact ordering code with the manufacturer before you change a BOM.
Reviewed by: Jasper · Updated: 2026-10-26
Verify against the datasheet before use.