2.495 V shunt reference with 100 mA cathode current
It is the through-hole DIP-8 variant of the industry-standard TL431 — the same die as the surface-mount versions but in a 0.300-inch 8-pin PDIP that suits wave-solder assembly and hand-prototyping. The ±2.2% initial tolerance is a standard commercial grade — adequate for closed-loop feedback in off-line flyback supplies, linear regulators, and isolated DC-DC converters where the loop gain absorbs the reference spread. For precision metrology or 12-bit ADC references, a tighter grade (0.5% or 1%) would be specified instead.
Through-hole DIP-8 — legacy footprint, active lifecycle
It remains a safe BOM line for sustaining production on through-hole boards and for MRO replacements in existing power-supply designs. The 8-DIP package (7.62 mm body width) mates with standard 0.100-inch pitch sockets or wave-solder through plated holes. Not rated for under-hood automotive ambient, but fine for most chassis-mount and indoor equipment.
Cathode current and output voltage range
The shunt regulator requires a minimum 1 mA cathode current to maintain regulation — below that the reference drifts out of spec. This covers the common 3.3 V, 5 V, 12 V, and 24 V rail regulation range used in most industrial power stages.