Texas Instruments TLV431AILPR

Overview

TLV431AILPR 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 TLV431AILPR datasheet, TLV431AILPR pinout, TLV431AILPR application, or TLV431AILPR equivalent, this page provides verified electrical specs, SC-70 package details, functional mode distinctions (open-loop comparator vs closed-loop shunt regulator), and real-world implementation guidance for voltage monitoring and Zener replacement use cases.

Technical Context

The TLV431AILPR integrates an internal 1.24 V bandgap reference and high-gain NPN-based amplifier driving a Darlington sink output stage. Its open-loop gain enables precise comparator operation with integrated reference, while closed-loop feedback via external resistors configures it as a programmable shunt regulator.

It operates with cathode-to-anode voltage (VKA) ≥ 1.24 V and requires ≥ 55 µA cathode current for regulation across –40°C to 85°C (I-grade). Thermal drift is specified at 6 mV over –40°C to 85°C, and dynamic impedance remains stable ≤ 0.4 Ω up to 15 mA cathode current.

Key Specifications

Pinout & Package

TLV431AILPR is packaged in ultra-small SC-70 (DCK) format (2.0 mm × 1.5 mm), offering 40% smaller footprint than SOT-23-3. The 6-pin package includes dedicated CATHODE, REF, ANODE, NC, and substrate connection terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431ACLP, TLV431AILPR offers 40% smaller footprint and 0.5% tighter tolerance; compared with TLV431BILPR, it trades 0.5% accuracy for lower unit cost while retaining identical thermal performance and SC-70 packaging.

Availability

TLV431AILPR is available at Aetrix Electronics and suitable for industrial power supplies, battery management systems, and embedded voltage supervision requiring stable component supply and long-term manufacturability.

Supply support for TLV431AILPR 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 shunt regulation and integrated reference applications in space-constrained, energy-efficient systems-targeting isolated SMPS, voltage monitoring, and Zener replacement use cases.

FAQ

What is the reference voltage tolerance of TLV431AILPR at 25°C?

The TLV431AILPR has a reference voltage tolerance of ±1% at 25°C, meaning its VREF is guaranteed between 1.228 V and 1.252 V under nominal conditions. This tolerance is confirmed in Section 5.6 of the official TI datasheet SLVS139Z and applies specifically to the 'A' grade variant. The 'I' suffix denotes industrial temperature qualification (–40°C to +85°C), but the ±1% spec holds only at 25°C.

Which package does TLV431AILPR use, and what are its dimensions?

TLV431AILPR uses the SC-70 (DCK) package, measuring 2.0 mm × 1.5 mm with a 0.65 mm pitch. This 6-pin surface-mount package is documented in TI's SLVS139Z datasheet Figure 4-5 and Table 4-1. Its compact size delivers a 40% footprint reduction versus standard SOT-23-3, making it ideal for dense PCB layouts in portable and modular power designs.

Can TLV431AILPR replace a standard Zener diode, and how does it differ?

Yes, TLV431AILPR is explicitly positioned as a Zener diode replacement in TI's datasheet Applications section. Unlike passive Zeners, it provides 1.24 V reference with ±1% tolerance, 0.25 Ω dynamic impedance, and sharp turn-on behavior due to active amplification. It requires only 55–80 µA minimum cathode current-far less than typical Zener knee currents-and maintains stable regulation across temperature and load variations.

What is the minimum cathode current needed for regulation in TLV431AILPR?

The TLV431AILPR requires a minimum cathode current (IK(min)) of 55 µA to enter and maintain regulation, rising to 80 µA maximum over the full –40°C to +85°C operating range. This value is specified in Section 5.6 (Electrical Characteristics for TLV431A) of the TI datasheet SLVS139Z and reflects the lowest current enabling sufficient internal gain for stable feedback operation.

How does TLV431AILPR behave in open-loop vs closed-loop configurations?

In open-loop mode, TLV431AILPR functions as a comparator with integrated 1.24 V reference-its cathode acts as an open-collector output switching near ground or pull-up rail. In closed-loop mode, feedback from cathode to REF pin configures it as a shunt regulator, maintaining precise voltage set by external resistors. Both modes are validated in TI's SLVS139Z Section 7.4 and Figure 8-2/8-1.