Texas Instruments TL432AQPKG3

Overview

TL432AQPKG3 from Texas Instruments is a precision programmable shunt voltage reference in SOT-89 package, featuring 1% initial accuracy at 25°C, −40°C to +125°C automotive-grade temperature operation, and adjustable output from 2.47 V to 36 V via two external resistors. It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current for feedback regulation in isolated DC/DC converters and industrial power supplies.

For engineers reviewing the TL432AQPKG3 datasheet, TL432AQPKG3 pinout, TL432AQPKG3 application, or TL432AQPKG3 equivalent, this page provides verified electrical specifications, thermal performance data, pin-level functional roles, real-world use cases in servo drives and AC inverters, and validated alternative parts with documented parameter differences.

Technical Context

The TL432AQPKG3 implements a three-terminal adjustable shunt regulator architecture with an internal precision bandgap reference and high-gain error amplifier. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable stable closed-loop regulation without external compensation in many applications.

Unlike the TL431, the TL432 variant uses a distinct pinout-REF, ANODE, CATHODE-in that order on pins 1–3 of the SOT-89 (PK) package. This configuration supports direct integration into compact feedback networks where anode grounding simplifies PCB routing in high-density power modules.

Key Specifications

Pinout & Package

SOT-89 (PK) package: 3-pin surface-mount, 4.5 mm × 2.5 mm body, exposed thermal pad (pin 2 connected to substrate and must be tied to ANODE or left open).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL432AQPKG3, TL431AQDBVR demands pinout adaptation but offers identical accuracy and thermal performance in smaller footprint, while TLVH431AQDBVR trades reference voltage flexibility for lower headroom at the cost of reduced transient immunity.

Availability

TL432AQPKG3 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, AC inverter & VF drives, and servo drive control module applications requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for TL432AQPKG3 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 and embedded processing technologies, with leadership in power management, signal chain, and high-reliability components.

The TL43x family was designed for precision voltage regulation in feedback paths of switching power supplies, replacing discrete Zener diodes with superior accuracy, temperature stability, and dynamic response-especially in automotive and industrial systems.

FAQ

What is the reference voltage tolerance of TL432AQPKG3 at 25°C?

The TL432AQPKG3 has a 1% initial reference voltage tolerance at 25°C, corresponding to a 2.47 V to 2.52 V range. This A-grade specification is confirmed in Section 6.10 of the TI SLVS543S datasheet and applies specifically to the Q-temp (−40°C to +125°C) version in PK package. The tolerance remains stable across temperature due to its bandgap-based core and low 14–34 mV VI(dev) drift.

How does the TL432AQPKG3 pinout differ from TL431AQPKG3?

The TL432AQPKG3 uses REF–ANODE–CATHODE pin order on pins 1–3 of the SOT-89 (PK) package, whereas TL431AQPKG3 uses REF–CATHODE–ANODE. This difference is intentional: TL432's ANODE-first arrangement simplifies grounding in configurations where the anode connects directly to system ground or a common reference plane. Both share identical electrical behavior, but TL432AQPKG3 requires updated PCB layout and schematic symbol mapping.

Can TL432AQPKG3 replace a Zener diode in a 24 V switching power supply?

Yes, TL432AQPKG3 can directly replace a Zener diode in a 24 V switching power supply feedback network. With its 2.47–36 V adjustable range, 1% accuracy, and 0.2 Ω dynamic impedance, it provides tighter regulation than typical 5% Zeners-especially under varying load and temperature. Its 1–100 mA sink capability also supports direct optocoupler LED drive without additional buffering, unlike passive Zeners.

What is the maximum cathode voltage rating for TL432AQPKG3?

The absolute maximum cathode-to-anode voltage (VKA) for TL432AQPKG3 is 37 V, per Section 6.1 of the TI SLVS543S datasheet. The recommended operating range is Vref to 36 V. Exceeding 37 V risks permanent damage. For 36 V operation, ensure sufficient derating based on ambient temperature and thermal resistance (RθJA = 52°C/W for PK package) to maintain junction temperature below 150°C.

Does TL432AQPKG3 require external capacitors for stability?

TL432AQPKG3 does not require external capacitors for basic regulation, but stability depends on load capacitance and cathode current. Figure 6-18 shows oscillation boundaries: for VKA = 5–15 V, instability may occur with CL > 0.01–0.1 µF at IKA < 10 mA. In practice, adding a 1 nF ceramic capacitor from cathode to anode improves phase margin in noisy industrial environments-verified in TI application note SLVA259.