Texas Instruments TLV431QPKG3

Overview

TLV431QPKG3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1.5% initial tolerance at 25°C, and operation across –40°C to 125°C. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical cathode current, and supports output voltage adjustment from 1.24 V to 6 V using two external resistors - ideal for secondary-side regulation in isolated 3.3 V flyback SMPSs.

For engineers reviewing the TLV431QPKG3 datasheet, TLV431QPKG3 pinout, TLV431QPKG3 application, or TLV431QPKG3 equivalent, this page provides verified electrical parameters, thermal behavior across automotive-grade temperature range, SC-70 package footprint data, functional mode distinctions (open-loop comparator vs. closed-loop shunt regulator), and validated alternative options for voltage reference design.

Technical Context

The TLV431QPKG3 implements an internal bandgap reference and NPN-based error amplifier driving a Darlington sink output stage. Its open-loop gain enables precise comparator operation with integrated 1.24 V threshold, while closed-loop feedback via REF and CATHODE pins achieves stable shunt regulation without mandatory output capacitance.

It operates with ≥1.24 V cathode-to-anode voltage headroom and requires ≥55 µA minimum cathode current for regulation over its full –40°C to 125°C automotive temperature range. Reference terminal current remains ≤0.5 µA, minimizing resistor-divider loading errors in precision feedback networks.

Key Specifications

Pinout & Package

TLV431QPKG3 uses the DCK (SC-70) 6-pin package, measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with exposed substrate pad connected internally to ANODE. Pin 2 (substrate) must be tied to ANODE or left floating per TI specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BQPKG3, TLV431QPKG3 trades initial accuracy for lower cost in automotive-compliant designs; compared with TLVH431QDBVR, it offers smaller SC-70 footprint and lower quiescent current but limits maximum cathode voltage to 6 V and current to 15 mA.

Availability

TLV431QPKG3 is available at Aetrix Electronics and suitable for automotive power management, isolated DC/DC converter feedback, and precision voltage monitoring requiring stable component supply across extended temperature ranges.

Supply support for TLV431QPKG3 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 voltage references and power management ICs.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications - including automotive, industrial, and telecom power systems.

FAQ

What is the reference voltage tolerance of TLV431QPKG3 at 25°C?

The TLV431QPKG3 has a ±1.5% reference voltage tolerance at 25°C, corresponding to a 1.24 V nominal V_REF with min/max values of 1.222 V and 1.258 V. This tolerance is specified for the "Q" grade variant and applies across all package options including the DCK (SC-70) used in TLV431QPKG3.

Can TLV431QPKG3 operate in open-loop comparator mode?

Yes, TLV431QPKG3 functions as a comparator with integrated 1.24 V reference when operated open-loop. With sufficient cathode current (>100 µA), it delivers high open-loop gain and sharp turn-on characteristics - enabling reliable voltage threshold detection without external reference components.

What is the minimum cathode current required for regulation in TLV431QPKG3?

The TLV431QPKG3 requires a minimum cathode current of 55 µA to maintain regulation at 25°C, rising to 100 µA maximum over its full –40°C to 125°C operating range. This low I_K(min) enables efficient operation in ultra-low-power systems such as battery-backed sensors and energy-harvesting nodes.

Does TLV431QPKG3 require an output capacitor for stability?

No, TLV431QPKG3 is internally compensated and stable without an output capacitor between CATHODE and ANODE. However, if a capacitor is added for noise filtering, Figure 5-19 in the datasheet provides phase margin guidance to ensure stability across capacitive loads up to 1 nF.

Which package does TLV431QPKG3 use, and what are its dimensions?

TLV431QPKG3 uses the DCK package - also known as SC-70 - with six terminals and nominal dimensions of 2.0 mm × 1.5 mm. This package is 40% smaller than standard SOT-23-3 and features an exposed substrate pad tied internally to the ANODE pin.