Texas Instruments TLVH431BMDBZREP

Overview

TLVH431BMDBZREP from Texas Instruments is a 3-terminal adjustable precision shunt voltage reference IC with 0.5% initial tolerance at 25°C, 1.24 V reference voltage, and operation down to 1.24 V cathode-anode voltage. It delivers stable regulation across –55°C to 125°C and supports cathode currents from 200 μA to 70 mA - ideal for secondary-side feedback in isolated 3.3-V flyback SMPS designs.

For engineers reviewing the TLVH431BMDBZREP datasheet, TLVH431BMDBZREP pinout, TLVH431BMDBZREP application, or TLVH431BMDBZREP equivalent, key selection criteria include low-voltage reference capability (1.24 V), wide cathode current range (200 μA–70 mA), extended temperature support (–55°C to 125°C), output impedance (0.25 Ω typ), and SOT-23 (DBZ) package compatibility with space-constrained power management layouts.

Technical Context

The TLVH431BMDBZREP operates as a programmable shunt regulator or open-loop comparator using internal bandgap reference and Darlington output stage. Its 1.24 V reference enables regulation below standard TL431 (2.5 V), while 200 μA minimum cathode current allows efficient operation in ultra-low-power feedback loops.

It functions in two primary modes: closed-loop shunt regulation (with resistive divider feedback between cathode and reference pins) and open-loop comparator mode (reference pin driven externally). Internal compensation ensures stability without external capacitors, though phase margin vs. capacitive load is characterized up to 100 nF.

Key Specifications

Pinout & Package

SOT-23 (DBZ) package, 2.92 mm × 1.30 mm body size, 3-pin surface-mount configuration with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDBZR, TLVH431BMDBZREP adds aerospace-grade reliability features without sacrificing performance; compared with TL431CDBZR, it enables lower-voltage regulation and tighter tolerance but requires redesign of feedback networks due to different reference voltage and bias current.

Availability

TLVH431BMDBZREP is available at Aetrix Electronics and suitable for isolated power supplies, voltage monitoring systems, and precision comparator circuits requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for TLVH431BMDBZREP 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TLVH431B-EP product line was designed specifically for defense, aerospace, and high-reliability industrial applications - featuring controlled baseline, extended temperature operation (–55°C to 125°C), and full traceability per MIL-PRF-38535.

FAQ

What is the minimum cathode current required for regulation in TLVH431BMDBZREP?

The TLVH431BMDBZREP requires a minimum cathode current of 200 μA across its full operating temperature range (–55°C to 125°C) to maintain regulation. At 25°C, the typical minimum is 60–100 μA, but design must accommodate the worst-case 200 μA spec to ensure stability over temperature. Below this threshold, gain drops and regulation degrades.

Can TLVH431BMDBZREP replace a Zener diode directly in existing circuits?

Yes, TLVH431BMDBZREP can directly replace Zener diodes in most shunt reference applications, provided the anode is grounded, cathode connects to the regulated node, and reference pin is tied to the feedback point via resistors. Its 0.25 Ω dynamic impedance and 0.5% tolerance offer superior performance versus typical 5% Zeners, but layout must respect SOT-23 thermal limits under sustained >50 mA cathode current.

What is the maximum cathode voltage rating for TLVH431BMDBZREP?

The absolute maximum cathode-to-anode voltage for TLVH431BMDBZREP is 20 V, per the Absolute Maximum Ratings table. For reliable continuous operation, the recommended maximum is 18 V - exceeding this risks permanent damage. This limit applies regardless of cathode current level and must be respected in all designs, including transient conditions.

How does TLVH431BMDBZREP behave when used as a comparator?

In open-loop comparator mode, TLVH431BMDBZREP compares voltage at the REF pin to its internal 1.24 V reference. When REF exceeds 1.24 V, the cathode pulls low (sinks current); otherwise, it remains high-impedance. Output logic levels depend on external pull-up: low-state is ~1 V, high-state equals pull-up voltage - making it suitable for interfacing with 3.3-V logic but requiring attenuation for 1.8-V systems.

Is TLVH431BMDBZREP stable without an output capacitor?

Yes, TLVH431BMDBZREP is internally compensated and stable with no output capacitor between cathode and anode. However, if a capacitive load is present (e.g., downstream IC input capacitance or decoupling), stability depends on value: Figure 20–22 in the datasheet shows phase margin remains >5° for ≤100 nF at 2.5 V and 5 V cathode voltage. Larger capacitors require series resistance or careful layout to avoid oscillation.