Texas Instruments TLVH432AQDBZT

Overview

TLVH432AQDBZT from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-23-3 package, providing 1.24 V reference voltage with ±0.5% initial tolerance at 25°C, 100 μA to 70 mA cathode current range, and operation from –40°C to +125°C. It functions as an error amplifier or comparator with integrated reference in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH432AQDBZT datasheet, TLVH432AQDBZT pinout, TLVH432AQDBZT application, or TLVH432AQDBZT equivalent, key selection criteria include reference accuracy grade (A = 1%), cathode-to-anode voltage headroom (≥1.24 V), dynamic impedance (0.25 Ω), thermal stability over industrial/automotive temperature ranges, and compatibility with optocoupler-based secondary-side regulation.

Technical Context

The TLVH432AQDBZT implements a precision bandgap reference and high-gain transconductance amplifier in a 3-terminal shunt topology. Its internal architecture forces the REF pin to 1.24 V relative to ANODE when sufficient cathode current (≥100 μA) flows and VKA ≥ VREF, enabling closed-loop regulation via external resistor dividers.

Unlike the TLVH431, the TLVH432AQDBZT uses reversed pinout (REF–CATHODE–ANODE) in SOT-23-3, optimizing layout for compact flyback feedback networks. It operates stably without output capacitance but supports capacitive loading up to 10 nF while maintaining phase margin >45° at 5 V cathode voltage.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH432AQDBZT, TLVH431AQDBZT requires layout changes due to pinout reversal, while TLVH432BQDBZT delivers tighter reference accuracy without layout impact-making it the preferred upgrade path for accuracy-critical designs.

Availability

TLVH432AQDBZT is available at Aetrix Electronics and suitable for isolated flyback SMPS feedback, precision ADC references, Zener replacement, voltage monitoring, and comparator-with-reference applications requiring stable component supply across automotive, industrial, and telecom programs.

Supply support for TLVH432AQDBZT 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 technologies, with leadership in precision analog ICs and power conversion solutions.

The TLVH432AQDBZT belongs to TI's precision shunt regulator product line, designed specifically for secondary-side regulation in isolated DC/DC converters and low-voltage reference applications demanding high accuracy, low quiescent current, and extended temperature operation.

FAQ

What is the reference voltage tolerance of TLVH432AQDBZT at 25°C?

The TLVH432AQDBZT has a reference voltage tolerance of ±1% at 25°C, corresponding to a VREF range of 1.228 V to 1.252 V. This grade-A specification is confirmed in Section 5.6 of the official datasheet and applies across all operating conditions where cathode current is ≥100 μA and VKA ≥ VREF. The TLVH432AQDBZT maintains this tolerance within its full temperature range of –40°C to +125°C, with total VREF deviation ≤31 mV.

How does the TLVH432AQDBZT pinout differ from TLVH431AQDBZT?

The TLVH432AQDBZT uses REF–CATHODE–ANODE pinout (Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE) in the SOT-23-3 package, whereas TLVH431AQDBZT uses CATHODE–ANODE–REF (Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF). This reversal is explicitly documented in Figures 4-4 and 4-5 of the datasheet and affects PCB layout and schematic symbol assignment. TLVH432AQDBZT is optimized for compact optocoupler feedback routing.

Can TLVH432AQDBZT operate without an output capacitor?

Yes, TLVH432AQDBZT is internally compensated and operates stably without an output capacitor between CATHODE and ANODE. This is verified in Section 7.3 and Figure 5-15 through Figure 5-17 of the datasheet, which show phase margin remains >45° up to 10 nF capacitive load. Adding capacitance is optional and only recommended when specific transient response or noise filtering requirements exist.

What is the minimum cathode current required for regulation in TLVH432AQDBZT?

The TLVH432AQDBZT requires a minimum cathode current of 100 μA to maintain regulation, as specified in Sections 5.5–5.7 (IK(min) parameter). This value is guaranteed over the full temperature range (–40°C to +125°C) and is independent of output voltage setting. Below 100 μA, gain drops significantly, causing poor regulation and increased VREF deviation - a critical design constraint for ultra-low-power applications.

Does TLVH432AQDBZT support operation at 18 V cathode-to-anode voltage?

Yes, TLVH432AQDBZT supports cathode-to-anode voltages up to 18 V under continuous operation, as stated in Section 5.3 (Recommended Operating Conditions) and validated in Figure 5-3 (Cathode Current vs Cathode Voltage). Absolute maximum rating is 20 V (Section 5.1), but sustained operation above 18 V risks exceeding thermal limits depending on package and ambient conditions. Derating is advised above 15 V at high temperatures.