Shunt reference with ±0.5% tolerance — why it matters for the rail
The TL432BQPKG3 is an adjustable shunt voltage reference from the TL432 family, with a ±0.5% tolerance that holds the reference voltage tighter than the standard 1% or 2% grades. That tolerance directly sets the accuracy of a regulated output rail or comparator threshold — if your design budgets for a 1% reference, this part gives you margin without moving to a higher-cost series reference. The 100 mA cathode current rating is higher than the typical 50–60 mA of a standard TL431, so this part can drive an optocoupler LED or bias a pass transistor directly without an external buffer.
Package and footprint — SOT-89-3
Supplied in a SOT-89-3 surface-mount package (TO-243AA case code), with a collector tab that provides a low thermal resistance path to the PCB. The tab is the cathode terminal — the PCB copper area under it sets the junction-to-ambient thermal performance.