Texas Instruments TL431ACLPM

Overview

TL431ACLPM from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output voltage from 2.495 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low output noise-enabling high-accuracy feedback in isolated DC/DC converters and industrial AC/DC power supplies.

For engineers reviewing the TL431ACLPM datasheet, TL431ACLPM pinout, TL431ACLPM application, or TL431ACLPM equivalent, this page provides verified electrical specifications, thermal performance data, package-specific pin functions, real-world use cases in servo drive control and notebook PC adapters, and two validated alternative parts for design flexibility.

Technical Context

The TL431ACLPM implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V reference and high-gain error amplifier. Its sharp turn-on characteristic and active output stage replace Zener diodes in closed-loop regulation, supporting stable operation with external resistor dividers for precise voltage setting.

It features temperature-compensated bandgap reference circuitry, delivering ≤14 mV total reference voltage deviation over −40°C to 85°C (I-grade), and maintains low dynamic impedance (0.2 Ω typ.) across 1–100 mA cathode current-critical for transient response in switching power supply feedback paths.

Key Specifications

Pinout & Package

TL431ACLPM is supplied in the SOIC-8 (D) package (4.90 mm × 3.90 mm), with pins arranged in standard dual-inline configuration. Pin 1 is CATHODE, Pin 2 is REFERENCE, and Pin 3 is ANODE; Pins 4–8 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACLPM, TL431CDBVR trades industrial temperature rating for compact packaging and lower cost, while TL431BQDBVR upgrades both accuracy and thermal range-making it suitable for mission-critical systems where ±0.5% regulation and 125°C operation are mandatory.

Availability

TL431ACLPM is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TL431ACLPM 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 technologies, with decades of expertise in precision reference and power control ICs.

The TL431 family was designed specifically for high-accuracy voltage regulation in isolated power supplies, industrial controls, and feedback-critical systems-emphasizing stability, low drift, and robustness across extended temperature ranges.

FAQ

What is the reference voltage tolerance of TL431ACLPM at 25°C?

The TL431ACLPM has a reference voltage tolerance of ±1% at 25°C, corresponding to its "A" grade designation. This means its nominal 2.495 V reference falls within 2.470 V to 2.520 V at room temperature, as confirmed in Section 6.8 of the TI datasheet SLVS543S. This tolerance directly impacts system-level output accuracy in feedback loops using the TL431ACLPM.

What temperature range is TL431ACLPM rated for?

The TL431ACLPM is rated for operation from −40°C to +85°C, indicated by the "I" suffix in its full part number (TL431AICLPM). This industrial temperature grade is validated per TI's recommended operating conditions in Section 6.4 and supports deployment in demanding environments such as motor drives and industrial power supplies without derating.

What is the dynamic impedance of TL431ACLPM and why does it matter?

The TL431ACLPM exhibits 0.2 Ω typical dynamic impedance (|ZKA|) at frequencies ≤1 kHz and cathode currents from 1 mA to 100 mA. This low value-specified in Sections 6.5–6.13-ensures minimal output voltage variation during rapid load transients, making the TL431ACLPM highly effective in switching power supply feedback paths where regulation stability is critical.

How is the output voltage set on TL431ACLPM?

The output voltage of TL431ACLPM is set externally using two resistors forming a voltage divider between cathode and anode, with the REF pin connected to the divider midpoint. When the voltage at REF reaches ~2.495 V, the device regulates by sinking cathode current. The formula is V_OUT = 2.495 × (1 + R1/R2), enabling adjustment from 2.495 V to 36 V as stated in the device description.

Which package type does TL431ACLPM use and what are its key mechanical dimensions?

TL431ACLPM uses the SOIC-8 (D) package with nominal body size 4.90 mm × 3.90 mm, as documented in the Device Information table. This surface-mount package supports automated assembly and provides thermal resistance (R_θJA) of 97°C/W, enabling reliable operation at up to 100 mA cathode current in standard PCB layouts without forced airflow.