TL431A Adjustable Shunt Regulator – SOT-23 (SMD) / TO-92 (THT)

TL431A adjustable shunt regulator is used as an exact reference voltage in switched-mode power supplies (SMPS), chargers, TV PSUs, game consoles, and other power electronics.

This product is sold in two electrically identical variants – choose the package depending on mounting:

• SOT-23-3 (SMD) – compact surface-mounted version
• TO-92-3 (Through-hole) – through-hole mounted, more thermally forgiving

TL431A has a reference voltage of approx. 2.495 V with high accuracy (±0.5%), making it suitable for critical feedback circuits via optocouplers.

The TL431 family appears under many designations from different manufacturers and is in most cases interchangeable when the tolerance class and package pinout match.

Compatibility: Can replace TL431-compatible variants such as AS431, EB5, KA431, AZ431 and similar designations, provided that the same accuracy class (A) and package are used.

Important: For sensitive SMPS applications, TL431A (A-class) is always recommended instead of the standard TL431 with poorer tolerance.

Typical applications:

• PSU feedback & voltage regulation
• Optocoupler control
• TV and console power supplies
• DC-DC converters

Product images are illustrative. The actual component may differ slightly in marking or appearance depending on the manufacturing batch.