Texas Instruments TLVH431CPKG3

Overview

TLVH431CPKG3 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 down to 100 µA cathode current. It delivers 0.25 Ω typical dynamic impedance and supports output voltage adjustment from 1.24 V to 18 V using two external resistors. This device serves as a high-accuracy, low-leakage replacement for Zener diodes in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431CPKG3 datasheet, TLVH431CPKG3 pinout, TLVH431CPKG3 application, or TLVH431CPKG3 equivalent, key selection criteria include its 1.24 V minimum operating voltage, –40°C to +125°C extended temperature range (Q-grade), SC-70 package footprint, and compatibility with optocoupler-based secondary-side regulation in 3.3 V power supplies.

Technical Context

The TLVH431CPKG3 implements a bandgap-referenced error amplifier with Darlington output stage, enabling sharp turn-on behavior and stable closed-loop regulation without external compensation. Its internal 1.24 V reference is trimmed at wafer test, and thermal drift is characterized across –40°C to +125°C for Q-grade operation.

It operates in two distinct functional modes: open-loop comparator mode (using integrated reference for voltage monitoring) and closed-loop shunt regulator mode (with resistive feedback from cathode to reference pin). The device maintains regulation with cathode current as low as 100 µA and exhibits < 0.1 µA off-state leakage at 18 V.

Key Specifications

Pinout & Package

TLVH431CPKG3 is packaged in SC-70 (DCK) - a 6-pin surface-mount package measuring 2.00 mm × 1.25 mm - offering 40% smaller footprint than SOT-23-3 while maintaining thermal performance suitable for space-constrained power management layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431CPKG3, TLVH431ACPKG3 offers improved initial accuracy for tighter regulation without layout changes, while TLVH431BPKG3 provides the highest precision for mission-critical monitoring - both retain identical pinout, thermal behavior, and 100 µA minimum cathode current requirement.

Availability

TLVH431CPKG3 is available at Aetrix Electronics and suitable for isolated SMPS feedback, precision voltage monitoring, low-power data converter references, and Zener replacement applications requiring stable component supply across automotive, industrial, and telecom end equipment.

Supply support for TLVH431CPKG3 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 design and high-reliability automotive qualification.

The TLVH431 family was engineered to extend shunt regulator capability into low-voltage domains (down to 1.24 V) while maintaining industrial-grade temperature performance and ultra-low quiescent current - targeting next-generation power conversion and sensing systems.

FAQ

What is the reference voltage tolerance of TLVH431CPKG3 at 25°C?

The TLVH431CPKG3 has a reference voltage tolerance of ±1.5% at 25°C, corresponding to a 1.24 V nominal V_REF with a range of 1.222 V to 1.258 V. This grade is designated by the absence of a suffix letter (C = standard grade), and it is fully characterized over the –40°C to +125°C temperature range for Q-grade operation. TLVH431CPKG3 maintains this specification without requiring external calibration.

Can TLVH431CPKG3 operate with cathode current below 100 µA?

No - TLVH431CPKG3 requires a minimum cathode current of 100 µA to maintain regulation and specified reference accuracy. Below this threshold, open-loop gain drops significantly, causing poor line/load regulation and increased V_REF deviation. Datasheet Figure 5-5 confirms IK(min) remains ≥100 µA across the full –40°C to +125°C range. TLVH431CPKG3 must be biased above this level in all active configurations.

What package type does TLVH431CPKG3 use, and how does it compare to SOT-23-3?

TLVH431CPKG3 uses the SC-70 (DCK) package - a 6-pin surface-mount variant measuring 2.00 mm × 1.25 mm. It offers a 40% smaller footprint than the 3-pin SOT-23-3 (2.92 mm × 1.30 mm) while maintaining compatible thermal resistance (R_θJA = 259°C/W). Pin 1 (CATHODE), Pin 2 (ANODE), and Pin 3 (REF) match functional positions in SOT-23 variants, but TLVH431CPKG3 adds two NC pins for mechanical robustness.

How does TLVH431CPKG3 differ from TL431 in low-voltage applications?

TLVH431CPKG3 operates down to 1.24 V cathode-to-anode voltage and 100 µA cathode current, whereas TL431 requires ≥2.5 V V_KA and ≥1 mA I_K. This makes TLVH431CPKG3 viable in 1.8 V and 3.3 V systems where TL431 cannot regulate. TLVH431CPKG3 also features lower reference input current (0.1–0.5 µA vs ~4 µA for TL431), enabling higher-impedance feedback networks without accuracy loss.

Is TLVH431CPKG3 suitable for automotive applications?

Yes - TLVH431CPKG3 is the Q-grade variant, qualified for operation from –40°C to +125°C and compliant with AEC-Q100 stress testing requirements for automotive electronics. Its 1.24 V reference, low leakage (<0.1 µA), and stable dynamic impedance (0.25 Ω) make it suitable for engine control unit (ECU) voltage supervisors, ADAS power monitors, and infotainment DC-DC feedback loops where reliability across extreme temperature cycles is mandatory. TLVH431CPKG3 meets these conditions without derating.