Texas Instruments TL432ACPKG3

Overview

TL432ACPKG3 from Texas Instruments is a precision programmable shunt voltage reference in SOT-89 (PK) package, delivering 2.47–2.52 V reference voltage at 25°C with ±1% initial tolerance (A grade), 6–16 mV full-temperature-range deviation (C-temp grade), and 0.2 Ω typical dynamic impedance. It operates from −40°C to 125°C and supports cathode current from 1 mA to 100 mA - used in secondary-side regulation of flyback SMPSs, adjustable power supplies, and Zener diode replacement circuits.

For engineers reviewing the TL432ACPKG3 datasheet, TL432ACPKG3 pinout, TL432ACPKG3 application, or TL432ACPKG3 equivalent, key selection criteria include its A-grade accuracy, C-temp thermal specification, SOT-89 thermal performance (R_θJA = 52°C/W), and distinct PK-package pinout versus TL431 variants.

Technical Context

The TL432ACPKG3 implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier and NPN output stage. Its REF pin senses voltage relative to ANODE, triggering cathode current sink when input exceeds V_ref; this enables precise feedback control without external op-amps.

Unlike TL431, the TL432ACPKG3 uses a reversed pinout in PK packaging: Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE - requiring PCB layout verification for drop-in replacement. It shares identical electrical specs with TL431AC but differs in pin assignment and thermal characteristics due to SOT-89's low R_θJA.

Key Specifications

Pinout & Package

SOT-89 (PK) package: 4.5 mm × 2.5 mm × 1.5 mm body, thermally enhanced with exposed tab connected to ANODE (Pin 2); suitable for medium-power dissipation up to 0.5 W with proper PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACPK, TL432ACPKG3 offers identical accuracy and thermal specs but mandates layout validation due to pin reversal; versus TL432AIPK, it adds 40°C higher max operating temperature at same price point - making it optimal for automotive under-hood deployment.

Availability

TL432ACPKG3 is available at Aetrix Electronics and suitable for switching power supply feedback, voltage monitoring & protection, adjustable linear regulators, and Zener diode replacement requiring stable component supply across automotive, industrial, and telecom applications.

Supply support for TL432ACPKG3 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 leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in precision reference design.

The TL43x family was engineered for high-accuracy, low-drift voltage referencing in safety-critical power systems - targeting automotive, industrial, and communications infrastructure where long-term stability and thermal robustness are essential.

FAQ

What is the exact pinout configuration of TL432ACPKG3?

The TL432ACPKG3 uses SOT-89 (PK) package with Pin 1 = REF, Pin 2 = ANODE (thermally connected to exposed tab), Pin 3 = CATHODE. This differs from TL431ACPKG3, which has Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF - requiring schematic and layout verification before substitution. The TL432ACPKG3 pinout is confirmed in TI's SLVS543P datasheet Figure 5 (TL432 PK top view).

Does TL432ACPKG3 support operation at 125°C?

Yes, TL432ACPKG3 is rated for operation from −40°C to 125°C per its "Q" temperature grade designation in the device nomenclature. This is validated across all electrical parameters in Section 7.7 (TL432Q characteristics) and Section 7.10 (TL432AQ characteristics) of the SLVS543P datasheet, including V_ref, I_min, and |z_KA|.

What is the maximum cathode current capability of TL432ACPKG3?

TL432ACPKG3 supports continuous cathode current up to 100 mA, as specified in Section 7.1 (Absolute Maximum Ratings) and Section 7.4 (Recommended Operating Conditions) of the SLVS543P datasheet. Derating is required above 70°C ambient due to thermal limits - at 125°C case temperature, maximum usable current drops to ~45 mA based on R_θJA = 52°C/W and T_J(max) = 150°C.

How does the dynamic impedance of TL432ACPKG3 affect feedback loop stability?

With 0.2 Ω typical dynamic impedance (|z_KA|), TL432ACPKG3 minimizes output impedance in feedback networks, reducing phase lag and improving phase margin in optocoupler-based SMPS loops. This value is measured at ≤1 kHz and 1–100 mA cathode current (Section 7.5–7.13), directly enabling tighter regulation without external compensation components.

Can TL432ACPKG3 replace a standard 2.5 V Zener diode directly?

TL432ACPKG3 can replace a 2.5 V Zener diode in most shunt-regulation roles, but requires two external resistors to set V_ref (unlike a standalone Zener). Its advantages include 0.2 Ω dynamic impedance vs. 10–50 Ω for Zeners, ±1% initial tolerance vs. ±5%, and 6–16 mV thermal drift vs. 20–100 mV - resulting in significantly improved accuracy and stability in TL432ACPKG3-based designs.