Texas Instruments TLV431AILPE3

Overview

TLV431AILPE3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C, and operation from 1.24 V to 6 V output range. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and supports secondary-side regulation in isolated flyback SMPSs.

For engineers reviewing the TLV431AILPE3 datasheet, TLV431AILPE3 pinout, TLV431AILPE3 application, or TLV431AILPE3 equivalent, key selection criteria include reference accuracy over temperature (±6 mV from –40°C to 85°C), ultra-low cathode current requirement, SC-70 package footprint, and compatibility with optocoupler-based feedback loops in 3.3 V systems.

Technical Context

The TLV431AILPE3 implements a 3-terminal adjustable shunt reference architecture with an internal bandgap reference and NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables precise voltage monitoring without external reference components.

In closed-loop configuration, it functions as a programmable shunt regulator by comparing the REF pin voltage against its internal 1.24 V reference and sinking cathode current to maintain regulation. It is internally compensated and stable without an output capacitor, supporting direct use in feedback networks of isolated DC/DC converters.

Key Specifications

Pinout & Package

TLV431AILPE3 is packaged in the ultra-small SC-70 (DCK) package (2.0 mm × 1.5 mm), offering 40% smaller footprint than SOT-23-3. This thermally efficient 6-pin surface-mount package features exposed substrate connection on Pin 2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt regulator applications.

Compared with TLV431AILPE3, TLV431ACDBVR trades industrial temperature range for tighter initial accuracy, while TLVH431IDBVR extends voltage capability at the cost of larger package and reduced integration density - TLV431AILPE3 balances accuracy, thermal range, and miniaturization for mainstream 3.3 V isolated power designs.

Availability

TLV431AILPE3 is available at Aetrix Electronics and suitable for isolated flyback SMPS regulation, precision voltage monitoring, Zener replacement, comparator-based threshold detection, and low-power reference applications requiring stable component supply and long-term manufacturability.

Supply support for TLV431AILPE3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company delivering analog and embedded processing solutions, with leadership in power management, signal chain, and high-reliability components.

The TLV431 family was designed as a low-voltage, low-power alternative to TL431 for modern energy-efficient power supplies, battery-operated systems, and space-constrained industrial controls - emphasizing precision, small footprint, and wide operating flexibility.

FAQ

What is the reference voltage tolerance of TLV431AILPE3 at 25°C?

The TLV431AILPE3 has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal value with a range of 1.228 V to 1.252 V. This tolerance is confirmed in Section 5.6 of the TI SLVS139Z datasheet and applies specifically to the 'A' grade variant, which TLV431AILPE3 belongs to.

Can TLV431AILPE3 replace a standard Zener diode in a 3.3 V regulator circuit?

Yes, TLV431AILPE3 can directly replace low-voltage Zener diodes in 3.3 V regulator circuits. Its 1.24 V reference, adjustable output up to 6 V, 0.25 Ω dynamic impedance, and 80 µA minimum cathode current provide superior accuracy, stability, and current drive compared to discrete Zeners - especially under varying temperature and load conditions.

What is the maximum cathode voltage rating for TLV431AILPE3?

The absolute maximum cathode voltage (V_KA) for TLV431AILPE3 is 7 V, measured with respect to the anode terminal. This rating is specified in Section 5.1 (Absolute Maximum Ratings) of the TI SLVS139Z datasheet and must not be exceeded to ensure device reliability and avoid permanent damage.

Which package type does TLV431AILPE3 use, and what are its dimensions?

TLV431AILPE3 uses the SC-70 (DCK) package, measuring 2.0 mm × 1.5 mm. This ultra-small 6-pin surface-mount package is documented in the "Package Information" section of the TI datasheet and offers a 40% smaller footprint than SOT-23-3 - confirmed by TI's mechanical drawings and orderable addendum.

How does TLV431AILPE3 behave in open-loop comparator mode?

In open-loop comparator mode, TLV431AILPE3 compares the voltage at its REF pin to its internal 1.24 V reference and sinks cathode current when the REF voltage exceeds that threshold. With proper cathode current (>80 µA), it delivers fast, rail-to-rail output swing - making it suitable for undervoltage detection and logic-level interfacing without external reference components.