Texas Instruments TLV431CLPM

Overview

TLV431CLPM from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and operation from 1.24 V to 6 V output range. It serves as a Zener replacement or integrated reference in isolated flyback secondary-side regulation.

For engineers reviewing the TLV431CLPM datasheet, TLV431CLPM pinout, TLV431CLPM application, or TLV431CLPM equivalent, this page delivers verified electrical specs, SC-70 package details, functional mode distinctions (open-loop comparator vs closed-loop shunt regulator), and real-world design implications for voltage monitoring and adjustable referencing.

Technical Context

The TLV431CLPM implements a bandgap-referenced error amplifier driving an NPN Darlington sink output stage. Its internal architecture enables stable closed-loop regulation without external compensation capacitors and supports open-loop comparator operation with integrated 1.24 V reference.

It operates across 0°C to 70°C (C-grade), requires ≥80 µA cathode current for regulation, and maintains 1.24 V reference within ±1.5% at 25°C and ±12 mV over full temperature range. The device achieves sharp turn-on via active output circuitry and exhibits 4 mV typical reference drift from 0°C to 70°C.

Key Specifications

Pinout & Package

TLV431CLPM is packaged in ultra-small SC-70 (DCK) format (2.0 mm × 1.5 mm), offering 40% smaller footprint than SOT-23-3. This thermally efficient 6-pin package supports high-density PCB layouts in space-constrained power and sensing circuits.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431CLPM, TLV431ACLP offers improved reference accuracy (±1% vs ±1.5%) at no layout or thermal penalty, while TLV431BCLP delivers laboratory-grade precision (±0.5%)-both retain identical pinout, dynamic impedance, and cathode current requirements.

Availability

TLV431CLPM is available at Aetrix Electronics and suitable for secondary-side SMPS regulation, voltage monitoring circuits, and Zener diode replacement applications requiring stable component supply across industrial and commercial production cycles.

Supply support for TLV431CLPM 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 decades of leadership in precision references and power management ICs.

The TLV431 family was designed to extend precision shunt regulation into low-voltage domains (1.24 V–6 V), addressing limitations of legacy TL431 in modern 3.3 V and lower systems while maintaining compatibility in feedback topologies.

FAQ

What is the reference voltage tolerance of TLV431CLPM at 25°C?

The TLV431CLPM has a reference voltage tolerance of ±1.5% at 25°C, meaning its V_REF falls between 1.222 V and 1.258 V under nominal conditions. This tolerance directly impacts the absolute accuracy of any regulated output voltage set by external resistors, and is specified separately from temperature-induced drift.

Can TLV431CLPM replace a standard Zener diode in a 2.5 V regulation circuit?

Yes, TLV431CLPM can directly replace a Zener diode in a 2.5 V shunt regulation circuit. With its 1.24 V reference and external resistor divider, it achieves precise 2.5 V output while offering superior performance: ±1.5% initial tolerance (vs typical 5% Zener), 0.25 Ω dynamic impedance (vs 10–100 Ω Zener), and lower temperature drift-making TLV431CLPM ideal for stable, low-power referencing.

What is the minimum cathode current required for TLV431CLPM to regulate properly?

The TLV431CLPM requires a minimum cathode current (I_K(min)) of 80 µA typical to enter and maintain regulation. Below this threshold, the device may not sustain stable reference behavior or exhibit sufficient open-loop gain. Designers must ensure the bias network supplies ≥80 µA under all operating conditions, including light-load and cold-temperature extremes.

Does TLV431CLPM require an output capacitor for stability?

No, TLV431CLPM does not require an output capacitor for stability. Its internal compensation ensures stable operation in standard shunt regulator configurations without external capacitance. However, if a capacitor is added (e.g., for noise filtering), Figure 5-19 in the datasheet provides phase margin guidance versus capacitive load to prevent oscillation-particularly relevant when driving long traces or optocoupler LEDs.

How does TLV431CLPM function in open-loop comparator mode?

In open-loop comparator mode, TLV431CLPM compares voltage at the REF pin to its internal 1.24 V reference. When the REF voltage exceeds V_REF, the cathode sinks current, pulling the output low (~1 V). When REF falls below V_REF, the cathode goes high-impedance, allowing an external pull-up to define the logic-high level. This mode eliminates need for separate reference and comparator ICs in threshold-detection circuits.