Texas Instruments TLV431AILPM

Overview

TLV431AILPM from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, 1% initial tolerance at 25°C, and operation from 1.24 V to 6 V output range. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and supports secondary-side regulation in isolated flyback SMPSs.

For engineers reviewing the TLV431AILPM datasheet, TLV431AILPM pinout, TLV431AILPM application, or TLV431AILPM equivalent, this device serves as a Zener replacement and integrated comparator-reference for low-voltage monitoring, adjustable referencing, and optocoupler-based feedback circuits requiring stable 1.24 V reference accuracy across –40°C to 85°C.

Technical Context

The TLV431AILPM implements a bandgap-referenced error amplifier driving a Darlington sink output stage, enabling precise closed-loop shunt regulation or open-loop comparator operation. Its internal architecture requires ≥55 µA cathode current to maintain linear regulation and forces the REF pin to 1.24 V ±1% when properly biased.

It operates without external compensation due to internal frequency compensation, supports cathode voltages from 1.24 V to 6 V, and exhibits 6 mV reference drift over –40°C to 85°C. The device functions with anode grounded and cathode connected to supply rail or optocoupler LED anode in isolated topologies.

Key Specifications

Pinout & Package

TLV431AILPM is packaged in the SC-70 (DCK) 6-pin surface-mount package (2.0 mm × 1.5 mm), offering 40% smaller footprint than SOT-23-3. Pin 1 is CATHODE, Pin 3 is REFERENCE, Pin 6 is ANODE; Pins 2, 4, and 5 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BILPM, TLV431AILPM trades 0.5% reference accuracy for lower unit cost while retaining identical temperature drift, dynamic impedance, and SC-70 footprint; compared with TLVH431AILP, it offers smaller size and lower quiescent current but sacrifices voltage headroom and current capability.

Availability

TLV431AILPM is available at Aetrix Electronics and suitable for industrial power supplies, battery management systems, and embedded sensor interfaces requiring stable component supply with guaranteed long-term availability.

Supply support for TLV431AILPM 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 precision analog ICs and power management solutions.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and energy-efficient applications-including isolated DC/DC converters, voltage supervisors, and programmable references.

FAQ

What is the operating temperature range for TLV431AILPM?

The TLV431AILPM is rated for operation from –40°C to +85°C (industrial grade). Its reference voltage drift is specified at 6 mV across this full range, and all electrical characteristics-including minimum cathode current (55–80 µA) and dynamic impedance (0.25 Ω)-are guaranteed within these limits. This makes TLV431AILPM suitable for deployment in automotive cabin modules, industrial PLC I/O, and outdoor sensor nodes.

Can TLV431AILPM replace a standard Zener diode in my circuit?

Yes, TLV431AILPM can directly replace many Zener diodes-especially those rated 1.2 V to 6 V-with significant improvements: ±1% initial tolerance (vs. ±5% typical for Zeners), 6 mV temp drift (vs. 20–50 mV), and 0.25 Ω dynamic impedance (vs. 10–100 Ω). To substitute, connect ANODE to ground, CATHODE to supply rail, and REF to voltage divider midpoint. Ensure cathode current exceeds 55 µA for regulation.

What is the minimum cathode current required for TLV431AILPM to regulate?

The TLV431AILPM requires a minimum cathode current (I_K(min)) of 55 µA to enter and sustain regulation mode at 25°C, rising to 80 µA across –40°C to 85°C. Below this threshold, the device exits regulation and behaves as an open-loop comparator. Designers must ensure external bias networks deliver sufficient current-e.g., using ≤100 kΩ upper divider resistor when V_IN = 5 V-to guarantee reliable startup and line/load regulation.

Does TLV431AILPM require an output capacitor for stability?

No, TLV431AILPM is internally compensated and remains stable without an output capacitor between CATHODE and ANODE-unlike many op-amp-based references. This eliminates capacitor-related aging, leakage, and ESR concerns. However, if a capacitor is added for noise filtering, Figure 5-19 in the datasheet provides phase-margin guidance versus capacitive load; values >1 nF may reduce stability margin depending on VKA.

How does TLV431AILPM function in comparator mode?

In comparator mode (open-loop), TLV431AILPM compares voltage at the REF pin to its internal 1.24 V reference. When REF exceeds 1.24 V, the CATHODE sinks current; when REF falls below, CATHODE goes high-impedance. With ≥55 µA cathode current supplied externally, it delivers fast response and logic-compatible output levels-~1 V low and ~V_SUP high-making TLV431AILPM ideal for undervoltage lockout or window detection without external components.