Texas Instruments TL432LIACDBZR

Overview

TL432LIACDBZR from Texas Instruments is a precision programmable shunt regulator in SOT-23 (DBZ) package, functioning as an adjustable voltage reference and error amplifier with 0.5% initial reference voltage tolerance at 25°C, 2.495 V nominal Vref, and sink-current capability up to 15 mA. It operates across −40°C to +125°C (Q-temp grade), features 0.3 Ω typical dynamic impedance, and replaces Zener diodes in secondary-side regulation of flyback SMPS.

For engineers reviewing the TL432LIACDBZR datasheet, TL432LIACDBZR pinout, TL432LIACDBZR application, or TL432LIACDBZR equivalent, key selection considerations include its optimized reference input current (IREF ≤ 0.4 µA), low temperature drift (≤27 mV over −40°C to +125°C), pinout-differentiated DBZ package versus TL431LI, and suitability for precision current sinking, voltage monitoring, and comparator-based level detection.

Technical Context

The TL432LIACDBZR implements a three-terminal shunt regulator architecture with an internal 2.495 V bandgap reference and high-gain op-amp driving a Darlington output stage. Its closed-loop operation enables precise voltage regulation via external resistor feedback between cathode and reference pins, while open-loop use supports comparator functionality with integrated reference.

Unlike standard linear regulators, it requires no external compensation capacitor for stability and maintains regulation with cathode current ≥1 mA. The device's DBZ package pinout (CATHODE–REF–ANODE) differs from TL431LI (CATHODE–ANODE–REF), making it incompatible without PCB layout revision - a deliberate design choice to avoid accidental substitution in legacy designs.

Key Specifications

Pinout & Package

SOT-23 (DBZ) package, 2.90 mm × 1.30 mm body size, surface-mount, 3-pin configuration with exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431LIBDBZR, TL432LIACDBZR avoids layout conflicts in new designs by separating pinout identity from function; versus TLVH431IDBVR, it delivers superior reference stability (27 mV vs 35 mV drift) and lower bias current - critical for high-precision, wide-temperature applications.

Availability

TL432LIACDBZR is available at Aetrix Electronics and suitable for automotive power management, industrial SMPS feedback, and precision instrumentation requiring stable component supply with guaranteed long-term continuity.

Supply support for TL432LIACDBZR 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and high-reliability components.

The TL43xLI family was designed specifically for precision voltage referencing and error amplification in isolated power supplies, battery monitors, and industrial control systems - emphasizing low drift, high accuracy, and robust thermal performance.

FAQ

What is the pinout configuration of TL432LIACDBZR?

The TL432LIACDBZR uses a SOT-23 (DBZ) package with Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This differs from TL431LI (Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF), so direct PCB substitution is not possible without layout modification. Always verify pin mapping against TI's SLVSDQ6A datasheet Figure 6 before integration.

Does TL432LIACDBZR require an output capacitor for stability?

No, TL432LIACDBZR is internally compensated and remains stable without an output capacitor between cathode and anode. However, if an output capacitor is used (e.g., for noise filtering), consult Figure 12 in the SLVSDQ6A datasheet to avoid oscillation - stability depends on capacitance value and cathode voltage conditions.

What is the minimum cathode current needed for TL432LIACDBZR to regulate properly?

TL432LIACDBZR requires a minimum cathode current (IKA) of 1 mA to enter and maintain regulation mode with sufficient open-loop gain. Below this threshold, response slows significantly and reference accuracy degrades. Designers should ensure IKA ≥ 1.5 mA in production circuits to accommodate temperature and tolerance margins.

How does TL432LIACDBZR differ from TL431LI in functional performance?

TL432LIACDBZR has identical electrical specifications, thermal performance, and functional behavior as TL431LI - including 0.5% Vref tolerance, 0.3 Ω dynamic impedance, and −40°C to +125°C operation. The sole difference is the DBZ package pinout, implemented to prevent accidental interchange in existing TL431LI-based designs.

Can TL432LIACDBZR be used as a comparator, and what are the key design considerations?

Yes, TL432LIACDBZR functions as a comparator with integrated 2.495 V reference in open-loop mode. Key considerations include supplying ≥1 mA cathode current for adequate gain, limiting input resistance to <10 kΩ to minimize IREF-induced error, and ensuring ≥10% overdrive voltage above Vref for fast response - e.g., trip point ≥2.75 V for B-grade devices.