Texas Instruments TLVH431BIDBZT

Overview

TLVH431BIDBZT from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% reference voltage tolerance at 25°C, 1.24 V nominal reference voltage, and operation down to 1.24 V cathode-to-anode voltage. It delivers stable regulation across –40°C to +125°C, supports cathode current from 100 μA to 70 mA, and features 0.25 Ω typical dynamic impedance-enabling use as a Zener replacement or error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431BIDBZT datasheet, TLVH431BIDBZT pinout, TLVH431BIDBZT application, or TLVH431BIDBZT equivalent, key selection criteria include initial VREF tolerance (B-grade = ±0.5%), thermal stability over industrial/automotive temperature ranges, ultra-low minimum cathode current requirement, and compatibility with optocoupler-based secondary-side regulation topologies.

Technical Context

The TLVH431BIDBZT implements an internal bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables precise voltage monitoring without external reference, while closed-loop operation-via resistive divider feedback from cathode to REF-configures it as a programmable shunt regulator with output voltage adjustable from 1.24 V to 18 V.

Unlike the TL431, the TLVH431BIDBZT achieves regulation at lower headroom (≥1.24 V) and lower minimum cathode current (100 μA vs. 1 mA), making it suitable for 3.3 V and 2.5 V systems. It is internally compensated and stable without an output capacitor, though phase margin versus capacitive load is characterized up to 100 nF.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92 mm × 1.30 mm body, gull-wing leads, JEDEC MO-178 compatible.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDBZT, TLVH431BIDBVT offers additional substrate control but increases board area and complexity, while TLVH432BIDBZT provides identical performance in a non-interchangeable pinout-neither is a drop-in replacement, and both require layout revision for migration.

Availability

TLVH431BIDBZT is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and precision analog signal chains requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant temperature performance.

Supply support for TLVH431BIDBZT 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-targeting isolated SMPS feedback, precision references, and voltage monitoring where legacy TL431 devices cannot operate due to headroom or current limitations.

FAQ

What is the reference voltage tolerance of TLVH431BIDBZT at 25°C?

The TLVH431BIDBZT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a V_REF range of 1.234 V to 1.246 V. This B-grade specification is confirmed in Section 5.7 of the TI datasheet SLVS555N and applies across the SOT-23-3 (DBZ) packaged variant. The tighter tolerance reduces calibration burden in precision applications such as data converter references and closed-loop power supplies.

Can TLVH431BIDBZT operate with a cathode-to-anode voltage below 2.5 V?

Yes, TLVH431BIDBZT is explicitly designed for low-voltage operation down to 1.24 V cathode-to-anode (V_KA), unlike the TL431 which requires ≥2.5 V. This capability is validated across its full operating range (100 μA to 70 mA cathode current, –40°C to +125°C), making TLVH431BIDBZT suitable for 3.3 V, 2.5 V, and even 1.8 V system rails where traditional shunt references fail to regulate.

What is the minimum cathode current required for regulation in TLVH431BIDBZT?

The TLVH431BIDBZT requires a minimum cathode current (I_K(min)) of 100 μA to maintain regulation, as specified in Sections 5.5–5.7 of the datasheet. This value is guaranteed over temperature (–40°C to +125°C) and enables stable operation in ultra-low-power modes, such as standby regulation in battery-powered systems or light-load conditions in flyback converters.

Is TLVH431BIDBZT pin-compatible with TLVH432BIDBZT?

No, TLVH431BIDBZT is not pin-compatible with TLVH432BIDBZT. While both are SOT-23-3 packaged devices with identical electrical specifications, their pinouts differ: TLVH431BIDBZT uses CATHODE–REF–ANODE (Pin 1–2–3), whereas TLVH432BIDBZT uses REF–CATHODE–ANODE. Interchanging them without PCB modification will result in incorrect connections and functional failure.

Does TLVH431BIDBZT require an output capacitor for stability?

No, TLVH431BIDBZT is internally compensated and stable without an output capacitor between cathode and anode-unlike many linear regulators. However, if a capacitor is added for noise filtering or transient response, Figures 5-15 through 5-17 in the datasheet characterize phase margin versus capacitive load (up to 100 nF) at multiple cathode voltages, enabling safe selection of external capacitance.