Precision shunt reference, TO-92-3, 0.4% initial accuracy
The STMicroelectronics TL1431IZ-AP is a three-terminal adjustable shunt voltage reference in a through-hole TO-92-3 package. It delivers a programmable output from 2.5 V up to 36 V with a ±0.4% initial tolerance and a 100 ppm/°C temperature coefficient, sourcing up to 100 mA of cathode current. This part operates across -40°C to 105°C ambient, making it suitable for industrial control, power supply feedback loops, and data-acquisition systems where a stable reference over temperature is needed. The minimum cathode current is 1 mA, which sets the bias floor for proper regulation.
Package variants and supply format
Supplied in Tape & Box (TB) and Cut Tape (CT) formats, the TL1431IZ-AP uses the standard TO-92-3 footprint (TO-226AC). The through-hole body is identical to the bulk-packaged TL1431IZ sibling — same die, same ±0.4% grade — so a BOM swap between the two requires no board change, only a pick-and-place format adjustment for the tape feed.
Peer comparison — temp range and tolerance grades
The closest sibling is the TL1431IZ (Bulk), which shares the same ±0.4% tolerance, 100 ppm/°C tempco, and full industrial temperature range (-40°C to 105°C). The TL1431CZ-AP narrows the temp range to -20°C to 70°C but drops the tempco to 90 ppm/°C — a tighter drift spec for commercial-only environments. The TL1431AIZT offers a tighter ±0.25% tolerance at the same industrial temp range, but ships in Tape & Reel (TR) rather than the TB/CT formats of this part.