Texas Instruments TLVH431AIDBZT

Overview

TLVH431AIDBZT from Texas Instruments is a low-voltage adjustable precision shunt regulator IC with 1.24 V reference voltage, ±1% initial tolerance at 25°C (A-grade), and operation down to 100 µA cathode current. It functions as a programmable voltage reference or comparator in isolated flyback SMPS feedback loops, secondary-side regulation, and low-leakage Zener replacement circuits.

For engineers reviewing the TLVH431AIDBZT datasheet, TLVH431AIDBZT pinout, TLVH431AIDBZT application, or TLVH431AIDBZT equivalent, key selection criteria include reference accuracy over temperature, dynamic impedance (0.25 Ω), cathode current range (100 µA–70 mA), and SOT-23-3 package compatibility for space-constrained power management designs.

Technical Context

The TLVH431AIDBZT implements an internal 1.24 V bandgap reference and high-gain transconductance amplifier driving a Darlington output stage. Its open-loop mode enables comparator functionality with integrated reference, while closed-loop operation-using external resistive feedback between cathode and reference pins-configures it as a shunt regulator with adjustable output from 1.24 V to 18 V.

It operates across –40°C to +125°C (Q-grade thermal range), maintains 0.25 Ω typical dynamic impedance up to 70 mA cathode current, and achieves <0.5 µA reference input current-enabling ultra-low-power monitoring and regulation without external biasing.

Key Specifications

Pinout & Package

SOT-23-3 package (DBZ): 2.92 mm × 1.30 mm body, 3-pin surface-mount, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDBZT and TLV431ACDBVR, the TLVH431AIDBZT delivers optimal balance of accuracy (±1%), extended temperature range (–40°C to +125°C), and compact SOT-23-3 packaging-making it the preferred choice for industrial power supplies and automotive subsystems requiring robust, field-proven performance.

Availability

TLVH431AIDBZT is available at Aetrix Electronics and suitable for isolated flyback SMPS feedback, precision voltage monitoring, and low-leakage shunt regulation requiring stable component supply across automotive, industrial, and telecom power designs.

Supply support for TLVH431AIDBZT 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 leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation and integrated-comparator applications-targeting next-generation power supplies, sensor interfaces, and battery-efficient systems demanding sub-2 V reference capability.

FAQ

What is the reference voltage tolerance of TLVH431AIDBZT at 25°C?

The TLVH431AIDBZT has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal value ranging from 1.228 V to 1.252 V. This A-grade specification is confirmed in Section 5.6 of the official TI datasheet SLVS555N and applies across all operating conditions unless otherwise noted. The TLVH431AIDBZT maintains this tolerance within its full temperature range when used with proper cathode current and layout practices.

Can TLVH431AIDBZT replace a standard Zener diode in low-power applications?

Yes, TLVH431AIDBZT serves as a high-performance Zener diode replacement with critical advantages: 0.25 Ω dynamic impedance (vs. >10 Ω for typical Zeners), <0.1 µA off-state cathode current (vs. >1 µA), and ±1% reference accuracy over temperature. Its adjustable output (1.24–18 V) and SOT-23-3 footprint enable direct substitution in voltage clamp, rail monitoring, and biasing circuits-especially where leakage, stability, or precision are design constraints. TLVH431AIDBZT requires only two external resistors for configuration.

What is the minimum cathode current required for regulation in TLVH431AIDBZT?

The TLVH431AIDBZT requires a minimum cathode current of 100 µA to maintain regulation, as specified in Section 5.5 of the TI datasheet. This value is valid across the full operating temperature range (–40°C to +125°C) and ensures sufficient internal bias for the Darlington output stage and reference amplifier. Below 100 µA, gain drops significantly, causing poor regulation or comparator hysteresis. Designers must ensure external circuitry supplies ≥100 µA under all operating conditions, including light-load or standby modes.

Does TLVH431AIDBZT require an output capacitor for stability?

No, TLVH431AIDBZT is internally compensated and stable without an output capacitor between cathode and anode-unlike many linear regulators. This eliminates mandatory bypass components and simplifies layout. However, if an output capacitor is added for noise filtering or transient suppression, Figures 5-15 through 5-17 in the TI datasheet provide phase-margin guidance versus capacitive load (up to 10 nF) at various cathode voltages. TLVH431AIDBZT remains stable across its full 100 µA–70 mA cathode current range without external compensation.

How does the pinout of TLVH431AIDBZT differ from TLVH432 variants?

TLVH431AIDBZT uses the standard SOT-23-3 pinout: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. In contrast, TLVH432 variants (e.g., TLVH432AIDBZT) reverse Pins 1 and 2: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. This difference is explicitly documented in Figures 4-4 and 4-5 of the TI datasheet. TLVH431AIDBZT is not pin-compatible with TLVH432 devices; swapping them without PCB revision causes functional failure due to reversed reference and cathode connections.