TL431AIDR2G

TL431AIDR2G is Texas Instruments’ TL431A programmable shunt regulator (precision reference) in a SOT-23 package with RoHS/reel packaging. It acts like an adjustable Zener: it holds the REF-to-ANODE voltage at about 2.495 V and sinks cathode current to regulate a voltage set by a resistor divider from Vout to REF.
Key points:
- Vref ≈ 2.495 V
- Cathode current up to about 100 mA (min. for regulation a few mA)
- Maximum cathode–anode voltage ≈ 36 V
- Temperature range typically −40 to +125 °C
- Vout set by R1/R2: Vout ≈ Vref × (1 + R1/R2) + Iref × R1
Package: SOT‑23, lead-free, reel (IDR2G).
Typical uses: post-regulation in power supplies, voltage reference in DC-DC converters, and LED-driver/regulation circuits.

Equivalent parts to TL431AIDR2G (1.24 V adjustable shunt regulator):
- TL431A/B/C (TI)
- TLV431 (TI)
- KA431 (ROHM)
- NCP431 (ON Semiconductor)
- REF431 (Analog Devices)
- AZ431 (Diodes Inc)
- MCP431 (Microchip)
- LMV431 / LM431 (various vendors)

Here are the key features of TL431AIDR2G (adjustable precision shunt regulator):
- 2.495 V reference (bandgap) for precision regulation
- External resistor divider lets you set Vout (acts like an adjustable zener)
- Maximum cathode current: up to about 100 mA
- Maximum cathode-to-anode voltage (VKA): up to ~36 V
- Low dynamic impedance and fast response for good line/load regulation
- Initial accuracy typically around 1% at 25°C (temperature effects minimized with market-standard specs)
- Wide operating temperature range suitable for industrial/consumer use (typical -40°C to 125°C)
- Available in small packages (SOT-23/SC-70 family variants) for compact designs
- Applications: voltage regulation, reference circuits, post-regulation, feedback in switching regulators
Note: exact packaging and temp specs may vary by lot; refer to the datasheet for final numbers.

- Pin count: 3 (Reference, Cathode, Anode)
- Function: Programmable precision shunt regulator (adjustable zener). It uses an internal 2.495 V reference and, via the reference input, regulates the cathode–anode voltage by shunting current to maintain the set output in power-supply feedback circuits.

Manufacturer: Texas Instruments (TI).
Company type: TI is a US-based multinational semiconductor company that designs and manufactures analog and embedded-processing integrated circuits.

Typical application areas for TL431AIDR2G:
- Feedback reference in switch-mode power supplies (buck/boost/flyback)
- Post-regulation reference and error amplifier in linear regulators
- Constant-current LED drivers and indicator LEDs
- Precision voltage reference for instrumentation, ADCs, and analog circuits
- Battery charger control loops and charging regulators
- Programmable Zener substitute for simple overvoltage/voltage reference needs
Notes: TL431 is a programmable shunt regulator with a 2.495 V reference, used as a versatile reference/regulator in many power-management designs.

SOT-23-3 (three-pin) surface-mount package.