Texas Instruments TLVH432AQDBZR

Overview

TLVH432AQDBZR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-23-3 package, featuring 1.24 V reference voltage (±1% at 25°C), 100 μA to 70 mA cathode current range, 0.25 Ω typical dynamic impedance, and operation from –40°C to +125°C. It serves as an integrated voltage reference and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH432AQDBZR datasheet, TLVH432AQDBZR pinout, TLVH432AQDBZR application, or TLVH432AQDBZR equivalent, key selection criteria include its A-grade 1% initial VREF tolerance, SOT-23-3 pinout (REF–CATHODE–ANODE), 1.24 V minimum regulation voltage, and suitability for secondary-side regulation in 3.3 V/5 V isolated power supplies.

Technical Context

The TLVH432AQDBZR implements a precision bandgap reference with high-gain transconductance amplifier driving a Darlington output stage. Its internal architecture enables sharp turn-on behavior and stable closed-loop regulation when configured with external resistive feedback between cathode and reference pins.

Unlike the TLVH431, the TLVH432AQDBZR uses a distinct 3-pin SOT-23 pinout (REF–CATHODE–ANODE) optimized for compact layout in space-constrained power rails and optocoupler-coupled feedback networks. It operates down to 1.24 V cathode-to-anode voltage and maintains regulation across industrial and automotive temperature ranges.

Key Specifications

Pinout & Package

SOT-23-3 package (2.92 mm × 1.30 mm body size) with gull-wing leads; RoHS-compliant, surface-mountable, thermal resistance R_θJA = 206°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AQDBZR, TLVH432AQDBZR enables direct integration into new designs targeting optimal optocoupler feedback layout; versus TLVH432BQDBZR, it trades 0.5% accuracy for lower unit cost while retaining identical thermal, current, and stability characteristics.

Availability

TLVH432AQDBZR is available at Aetrix Electronics and suitable for isolated flyback SMPS design, precision ADC reference generation, and low-voltage power rail monitoring requiring stable component supply across automotive, industrial, and computing end markets.

Supply support for TLVH432AQDBZR 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 ICs, with leadership in precision reference and power control technologies.

The TLVH432AQDBZR belongs to TI's precision shunt regulator product line, engineered specifically for low-voltage, high-accuracy feedback in isolated power supplies and compact voltage monitoring systems.

FAQ

What is the pin configuration of TLVH432AQDBZR?

The TLVH432AQDBZR uses a 3-pin SOT-23 package with pin 1 = REF, pin 2 = CATHODE, pin 3 = ANODE. This differs from the TLVH431 family's ANODE–CATHODE–REF arrangement and is optimized for direct connection to optocoupler anodes in flyback feedback paths. Always verify orientation using TI's DBZ package drawing SLVS555N Figure 4-5.

What is the minimum cathode current required for regulation in TLVH432AQDBZR?

The TLVH432AQDBZR requires a minimum cathode current of 100 μA to maintain regulation across its full temperature range (–40°C to +125°C). Below this level, gain drops and reference accuracy degrades; design must ensure IK ≥ 100 μA under all operating conditions, including light-load and cold-start scenarios.

Can TLVH432AQDBZR replace a standard Zener diode?

Yes, TLVH432AQDBZR directly replaces low-voltage Zener diodes (e.g., 2.5 V, 3.3 V types) with superior performance: 0.25 Ω dynamic impedance vs. 10–100 Ω for Zeners, ±1% VREF tolerance vs. ±5% typical for Zeners, and 0.1 μA reference current enabling high-resistance bias networks. It also eliminates Zener leakage drift with temperature.

How does TLVH432AQDBZR achieve stability without an output capacitor?

TLVH432AQDBZR incorporates internal frequency compensation that ensures phase margin >45° across capacitive loads up to 10 nF. This eliminates the need for external cathode-to-anode capacitors in most applications, simplifying layout and reducing BOM count-verified per TI's Figure 5-15 through 5-17 stability curves in SLVS555N.

What is the maximum cathode voltage rating for TLVH432AQDBZR?

The absolute maximum cathode-to-anode voltage (V_KA) for TLVH432AQDBZR is 20 V. In normal operation, the recommended maximum is 18 V per Section 5.3 of the datasheet. Exceeding 20 V risks permanent damage; designs regulating >15 V should include clamping or derating margins.