Precision shunt reference — what the ±0.5% tolerance buys you
Its ±0.5% tolerance means the initial reference voltage at the adjust pin is held to within 12.5 mV of the nominal 2.495 V — tight enough for precision power-supply feedback loops, overvoltage protection thresholds, and A/D converter references where a 1% part would drift outside the error budget. It delivers up to 100 mA with a minimum cathode current of 700 µA, so it can drive optocoupler LEDs or bias a small load directly.
Package and footprint — 8-SOIC with tube delivery
The mounting type is surface mount. No special thermal pad or via stitching is required for this shunt reference; its dissipation is modest at the rated output current.
Lifecycle reality — obsolete, but still sourceable
It remains ROHS3 compliant. For BOM lines that already use this part, procurement must go through the independent surplus and broker channel.
Because the TL431BID is obsolete, it is not sitting on franchised distributor shelves. Independent stock varies by date code and region. When you submit an RFQ, the quote will reflect the prevailing spot price for available inventory — expect a premium over the original catalog price, especially if the part is in a tight allocation window for legacy industrial equipment repairs. For production runs, verify date code consistency and request traceability documentation from the broker. If you are filling a last-time-buy or repair order, this part is still findable, but plan for a longer lead time and higher per-unit cost than an active alternative.