Texas Instruments TLV431AQDBVRQ1

Overview

TLV431AQDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 qualified low-voltage adjustable precision shunt regulator used as a voltage reference, error amplifier, or comparator in automotive power management circuits. It delivers 1.24 V reference voltage (±1% at 25°C), operates from 1.24 V to 6 V cathode voltage, supports –40°C to 125°C ambient, and draws only 80 µA typical cathode current - enabling efficient secondary-side regulation in 3.3 V isolated flyback SMPSs.

For engineers reviewing the TLV431AQDBVRQ1 datasheet, TLV431AQDBVRQ1 pinout, TLV431AQDBVRQ1 application, or TLV431AQDBVRQ1 equivalent, key selection criteria include its 1.24 V low-voltage reference, ±1% initial tolerance (A-grade), 0.25 Ω dynamic impedance, automotive temperature range, and SOT-23-3 package compatibility with space-constrained vehicle ECUs and battery management systems.

Technical Context

The TLV431AQDBVRQ1 implements a three-terminal shunt topology with internal bandgap reference and Darlington output stage, enabling precise voltage regulation via external resistor feedback between cathode and reference pins. Its open-loop gain supports comparator operation with integrated 1.24 V threshold, while closed-loop configuration achieves stable regulation down to 1.24 V output.

It features internally compensated stability without mandatory output capacitance, though capacitive load limits are defined per VKA (e.g., ≤150 µF at VKA = VREF). The device requires ≥55 µA minimum cathode current for regulation and maintains 11 mV VREF drift across –40°C to 125°C - critical for automotive sensor biasing and power supply monitoring.

Key Specifications

Pinout & Package

SOT-23-3 (DBV) package: 2.90 mm × 1.30 mm body, 0.95 mm max height, gull-wing leads, RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BQDBVRQ1, TLV431AQDBVRQ1 trades 0.5% initial accuracy for lower cost in volume automotive applications where system calibration compensates for reference error; versus TL431ACDR, it enables lower-voltage regulation and meets automotive reliability standards but lacks extended voltage headroom.

Availability

TLV431AQDBVRQ1 is available at Aetrix Electronics and suitable for automotive battery monitoring, isolated flyback regulation, Zener replacement, overvoltage protection, and precision voltage referencing requiring stable component supply across production lifecycles.

Supply support for TLV431AQDBVRQ1 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 specializing in analog, embedded processing, and power management solutions for automotive, industrial, and communications markets.

The TLV431x-Q1 product line delivers AEC-Q100 qualified low-voltage shunt references optimized for secondary-side regulation, voltage monitoring, and comparator functions in automotive power systems operating from –40°C to 125°C.

FAQ

What is the reference voltage tolerance of TLV431AQDBVRQ1 at 25°C?

The TLV431AQDBVRQ1 has a reference voltage tolerance of ±1% at 25°C, meaning its VREF is guaranteed between 1.228 V and 1.252 V under those conditions. This 1.24 V nominal reference enables accurate voltage setting in feedback networks for automotive power supplies and sensor interfaces. TLV431AQDBVRQ1 maintains this specification across its full operating temperature range with a typical drift of only 11 mV from –40°C to 125°C.

Can TLV431AQDBVRQ1 replace a Zener diode in automotive circuits?

Yes, TLV431AQDBVRQ1 is explicitly designed as a precision Zener diode replacement, offering superior thermal stability (11 mV drift vs typical Zener's >50 mV), lower dynamic impedance (0.25 Ω vs >10 Ω), and adjustable output from 1.24 V to 6 V using two resistors. Its AEC-Q100 qualification, –40°C to 125°C rating, and low 80 µA cathode current make TLV431AQDBVRQ1 ideal for automotive voltage clamping, biasing, and regulation where discrete Zeners fall short on accuracy and reliability.

What is the minimum cathode current required for regulation in TLV431AQDBVRQ1?

The TLV431AQDBVRQ1 requires a minimum cathode current (IK(min)) of 55 µA to 100 µA to maintain regulation, depending on temperature - specified as 55 µA at –40°C and up to 100 µA at 125°C. This ultra-low requirement enables TLV431AQDBVRQ1 to operate efficiently in always-on automotive modules such as wake-up monitors and battery supervisors, where quiescent current must remain below 100 µA to preserve battery life during key-off states.

How does TLV431AQDBVRQ1 achieve stability without an output capacitor?

TLV431AQDBVRQ1 uses internal compensation to remain stable without an output capacitor between cathode and anode - a key advantage over many linear regulators. Its architecture avoids phase-margin degradation at typical loads, though capacitive loading above 150 µF at VKA = VREF can induce oscillation. Stability boundaries are documented in Figure 5-18 of the datasheet, allowing designers to select safe CL values for specific VKA conditions. This makes TLV431AQDBVRQ1 suitable for compact, capacitor-free feedback paths in space-constrained automotive PCBs.

Is TLV431AQDBVRQ1 pin-compatible with other TLV431x-Q1 variants?

Yes, TLV431AQDBVRQ1 is fully pin-compatible with TLV431BQDBVRQ1 and other SOT-23-3 packaged TLV431x-Q1 devices, sharing identical DBV footprint, pinout (REF–CATHODE–ANODE), and thermal characteristics. The only functional difference is the reference voltage tolerance: TLV431AQDBVRQ1 offers ±1% at 25°C, while TLV431BQDBVRQ1 provides ±0.5%. This allows drop-in substitution in existing layouts when tighter accuracy is later required, with no PCB or schematic changes needed for TLV431AQDBVRQ1.