Type a marking above. The match is case-insensitive, and the first three characters are enough. If a code is not in the table, it is not in TI’s DBZ addendum. Other makers may use the same code for a different device. Check the package and that maker’s marking document.
How TI’s names map: B = 0.5%, A = 1%, no letter = 2%. C = 0 to 70 °C, I = −40 to 85 °C, Q = −40 to 125 °C.
Irregular codes: TL431AI’s T3AG does not start with “TAI”. TL431BC uses “T3G”, not “TBC”. TL432BC does use “TBC”. Decoding by pattern alone gets these wrong.
TI DBZ marking table
| Orderable family | DBZ device markings | Tolerance | Temperature | SLVS543S page |
|---|---|---|---|---|
| TL431C | T3C3, T3CG, T3CS, T3CU | 2% | 0 to 70 °C | p.41 |
| TL431I | T3I3, T3IG, T3IS, T3IU | 2% | −40 to 85 °C | p.42 |
| TL431Q | T3Q3, T3QG, T3QS, T3QU | 2% | −40 to 125 °C | p.43 |
| TL431AC | TAC3, TACG, TACS, TACU | 1% | 0 to 70 °C | p.34 |
| TL431AI | T3AG, TAI3, TAIS, TAIU | 1% | −40 to 85 °C | p.35 |
| TL431AQ | TAQ3, TAQG, TAQS, TAQU | 1% | −40 to 125 °C | pp.36–37 |
| TL431BC | T3G3, T3GG, T3GS, T3GU | 0.5% | 0 to 70 °C | p.37 |
| TL431BI | T3F3, T3FG, T3FS, T3FU | 0.5% | −40 to 85 °C | pp.38–39 |
| TL431BQ | T3H3, T3HG, T3HS, T3HU | 0.5% | −40 to 125 °C | pp.39–40 |
| TL432AC | T4B3, T4BG, T4BS, T4BU | 1% | 0 to 70 °C | p.44 |
| TL432AI | T4A3, T4AG, T4AS, T4AU | 1% | −40 to 85 °C | p.44 |
| TL432AQ | T4D3, T4DG, T4DS, T4DU | 1% | −40 to 125 °C | p.45 |
| TL432BC | TBCG, TBCS, TBCU | 0.5% | 0 to 70 °C | p.45 |
| TL432BI | T4F3, T4FG, T4FS, T4FU | 0.5% | −40 to 85 °C | p.46 |
| TL432BQ | T4H3, T4HS, T4HU | 0.5% | −40 to 125 °C | p.46 |
| TL432C | T4CG, T4CS, T4CU | 2% | 0 to 70 °C | p.46 |
| TL432I | T4IG, T4IS, T4IU | 2% | −40 to 85 °C | p.47 |
| TL432Q | T4QG, T4QS, T4QU | 2% | −40 to 125 °C | p.47 |
Pinout (SLVS543S p.4)
| Pin (DBZ) | TL431 | TL432 |
|---|---|---|
| 1 | CATHODE | REF |
| 2 | REF | CATHODE |
| 3 | ANODE | ANODE |
Maximum cathode voltage is 36 V. Cathode current range is 1–100 mA. DBZ RθJA is 206 °C/W. The 2% Vref is 2440 / 2495 / 2550 mV. Iref is 2 µA typical / 4 µA maximum. Minimum regulating current is 0.4 mA typical / 1 mA maximum.
Worked examples
- “TAC3” is TL431AC: 1%, 0 to 70 °C. If the product must work at −20 °C, the I grade is needed instead (TL431AI, marked T3AG / TAI3 / TAIS / TAIU).
- “T4BS” is TL432AC. Soldered onto a TL431 footprint, REF and cathode are swapped and the circuit will not regulate.
- At IKA 10 mA and VKA 5 V, P = 50 mW and the rise is 50 mW × 206 °C/W, about 10.3 °C. At IKA 38.6 mA (the no-load case in the TL431 calculator example), P is about 193 mW, a rise of about 40 °C.
Pitfalls
- Fitting a TL432 where a TL431 belongs. The SOT-23 outlines are identical but pins 1 and 2 are swapped.
- Reading the 4th character as the grade. The 4th character (3, G, S or U) is the assembly site. The grade is in the first three characters.
- Assuming the code means the same thing on another maker’s part. This table covers TI DBZ parts only.
- Ignoring the package. DBV, DBZ and other packages have different pinouts. Confirm it is a 3-pin SOT-23 (DBZ) first.
Part numbers
TL431CDBZR, TL431ACDBZR, TL431BCDBZR, TL431AIDBZR, TL432ACDBZR. The R suffix is tape and reel. Confirm the exact orderable on TI’s product page. Information only.
Disclaimer
Marking data comes from TI’s Package Option Addendum as read on 26 Oct 2026. TI may add or change codes. The addendum in the current datasheet is the authority. Markings on parts from other makers, or on counterfeit parts, may not follow this table. A marking alone does not prove authenticity.
Updated: 2026-10-26 · Jasper