Diodes Incorporated TLV431AQE5TA

Overview

TLV431AQE5TA from Diodes Incorporated is an AEC-Q100 Grade 1 qualified, adjustable 1.24V precision shunt voltage reference in SOT25 package, delivering ±1% initial reference voltage tolerance at +25°C, 11mV max VREF deviation over −40°C to +125°C, and 0.25Ω typical dynamic output impedance. It operates as a Zener diode replacement in automotive power management, battery monitoring, and programmable voltage supervision circuits.

For engineers reviewing the TLV431AQE5TA datasheet, TLV431AQE5TA pinout, TLV431AQE5TA application, or TLV431AQE5TA equivalent, key selection criteria include its automotive qualification (AEC-Q100 Grade 1), adjustable 1.24–18V output via external resistors, low 80µA minimum cathode current, and SOT25 thermal performance (250°C/W θJA, 500mW PDIS).

Technical Context

The TLV431AQE5TA implements a bandgap-based shunt regulator architecture with three-terminal feedback control (Anode, Cathode, Reference). Its internal reference is trimmed for 1.24V nominal output and stabilized across −40°C to +125°C using curvature-compensated circuitry.

It functions by sinking variable cathode current to maintain precise voltage at the REF pin relative to ANODE, enabling high-accuracy voltage setting (1.24–18V) with two external resistors. The device supports stable operation down to 80µA cathode current and exhibits <0.25Ω dynamic impedance below 1kHz.

Key Specifications

Pinout & Package

SOT25 package: 5-pin surface-mount, thermally enhanced plastic case with die attached to Pin 2; Pin 2 must be left floating or connected to Pin 5 per datasheet layout guidance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BQE5TA, TLV431AQE5TA trades 0.5% initial accuracy for lower cost and broader automotive qualification; versus TL431ACDT, it delivers superior thermal stability, lower impedance, and certified automotive readiness-critical for safety-critical vehicle subsystems.

Availability

TLV431AQE5TA is available at Aetrix Electronics and suitable for automotive battery monitoring, programmable overvoltage protection, and ECU power supervision requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TLV431AQE5TA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for automotive, industrial, and computing markets.

The TLV431Q series was designed specifically for AEC-Q100-compliant automotive voltage reference applications-emphasizing precision, thermal robustness, and PPAP-ready manufacturability in IATF 16949 facilities.

FAQ

What is the maximum cathode voltage rating for TLV431AQE5TA?

The absolute maximum cathode-to-anode voltage (VKA) is 20V. Operation above this level risks permanent damage. In recommended conditions, VKA is limited to 18V to ensure reliable regulation and avoid exceeding junction temperature limits under worst-case power dissipation.

Can TLV431AQE5TA replace a standard Zener diode in existing designs?

Yes-it directly replaces Zener diodes in shunt regulator configurations. Unlike Zeners, it offers 1.24V minimum reference, ±1% tolerance, and significantly better temperature stability (11mV drift vs. typical Zener's >50mV). External resistor values must be recalculated to set the desired output voltage using VOUT = 1.24 × (1 + R1/R2).

Why must Pin 2 and Pin 5 both be left floating or connected together in SOT25?

Per the datasheet, the silicon die in the SOT25 package is physically mounted on Pin 2, creating an internal electrical connection between Pins 2 and 5 (both Anode terminals). Leaving one unconnected while driving the other creates unintended current paths and thermal stress. Connecting them ensures proper current distribution and avoids reliability risks.

Is TLV431AQE5TA suitable for use in a series regulator configuration?

Yes-the device is commonly used in series regulator topologies (e.g., Figure 3 in DS36915). It serves as the precision reference for an external pass transistor, enabling adjustable output voltages with improved accuracy and thermal performance over fixed linear regulators. Bias current for the TLV431AQE5TA must be maintained ≥80µA across all operating conditions.