TL431AIYDT

TL431AIYDT is TI’s variant of the TL431, a three‑terminal programmable shunt regulator (precision adjustable “zener”). It provides a stable 2.495 V reference and shunts current between cathode and anode to regulate an external feedback node in power supplies and regulators.
How it works:
- The REF pin is tied to a resistor divider from Vout to ground.
- When VREF ≈ 2.495 V, the device holds Vout by altering cathode current.
- If Vout rises, more cathode current flows; if it falls, less.
Key points:
- Pins: Reference, Cathode, Anode (pinout depends on package; check AIYDT datasheet).
- VKA up to about 36 V; regulation typically requires ~1 mA to tens of mA.
- Output set by R1 (Vout to REF) and R2 (REF to ground): Vout ≈ Vref × (1 + R1/R2).
- Used in SMPS feedback, linear regs, battery chargers, and overvoltage protection.
For exact electrical specs, temperature range, and packaging details, see the TL431AIYDT datasheet.

Equivalents (2.495 V adjustable shunt regulator): TL431 family (TL431A/B/C), TLV431, LMV431/LMV431A, KA431, REF431/REF431A. These are drop-in style substitutes with similar A-K-R pinouts; always check the specific package and ratings in the datasheet before replacing.

Here are the typical features of TL431AIYDT (TL431 family, programmable shunt regulator):
- Programmable shunt regulator with a fixed 2.495 V reference (Vref).
- Output voltage set by external resistor divider: Vout = Vref(1 + R1/R2) + Iref·R1.
- Cathode current range for regulation: about 1 mA to up to 100 mA (with max ~100 mA).
- Wide maximum cathode-to-anode voltage (VKA) up to roughly 30–37 V depending on version.
- High reference accuracy: A-grade around 0.5% (25°C), B-grade around 1% (typical).
- Low dynamic impedance for good load regulation.
- Temperature range typically -40°C to +125°C (industrial/ military grades available).
- Stability options: can require a capacitor from REF to CATHODE for improved ripple rejection and stability in some circuits.
- RoHS-compliant and available in tape-and-reel packaging (AIYDT variant).
Note: Exact electrical specs (VKA limit, Imin/Imax, accuracy) can vary by exact lot/grade; consult the specific datasheet for AIYDT to confirm.

Pin count: 3 pins.
Function: TL431AIYDT is a programmable precision shunt regulator (adjustable zener). It has three terminals: Anode, Reference, and Cathode. It provides a 2.495 V internal reference and is used in feedback networks to regulate output voltages.

- Manufacturer: Texas Instruments (TI).
- About the company: TI is an American multinational technology company that designs and manufactures semiconductors and integrated circuits, especially analog and mixed-signal devices used in industrial, automotive, and consumer electronics.

TL431AIYDT is a programmable precision shunt regulator (2.495 V reference). Common application areas:
- SMPS feedback: acts as the error amplifier in buck/boost converters.
- Adjustable voltage references for linear regulators and instrumentation.
- Overvoltage protection and crowbar circuits.
- LED driver circuits (constant-current regulation).
- Battery chargers and general analog control/reference circuits (DAC/ADC references).

TL431AIYDT is a 3-pin adjustable shunt regulator in a SOT-23-3 (SC-70-3) surface-mount package.