Texas Instruments TLVH431AQDCKT

Overview

TLVH431AQDCKT from Texas Instruments is a low-voltage adjustable precision shunt regulator in SC-70 package, delivering 1.24 V reference voltage with ±0.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation from 1.24 V to 18 V output range. It serves as an ultra-low-leakage Zener replacement and integrated reference comparator in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431AQDCKT datasheet, TLVH431AQDCKT pinout, TLVH431AQDCKT application, or TLVH431AQDCKT equivalent, key selection criteria include cathode current range (100 μA–70 mA), thermal stability over –40°C to +125°C, SC-70 footprint compatibility, and open-loop comparator functionality with built-in 1.24 V reference.

Technical Context

The TLVH431AQDCKT implements a precision bandgap reference and high-gain NPN-based error amplifier in a 3-terminal shunt topology. Its internal Darlington output stage enables sharp turn-on behavior and stable regulation with no external compensation required. The device operates in two functional modes: closed-loop shunt regulation (with resistive feedback from cathode to REF) and open-loop comparator mode (with REF driven externally).

Unlike the TL431, it achieves regulation down to 1.24 V with only 100 μA minimum cathode current, enabling use in 3.3 V and lower-output isolated power supplies. Its 0.25 Ω dynamic impedance and <0.5 μA reference input current support high-accuracy voltage monitoring and low-power data converter references.

Key Specifications

Pinout & Package

TLVH431AQDCKT uses the SC-70 (DCK) 6-pin package (2.00 mm × 1.25 mm), featuring cathode, anode, and reference terminals plus two NC pins and one substrate connection (Pin 2) that must be tied to anode or left open.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AQDCKT, TLVH431BQDCKT extends guaranteed accuracy to +125°C without trade-offs, while TLVH432AQDBZR offers identical specs in a larger, pinout-different package-neither is pin-compatible, but both serve overlapping shunt regulation use cases with distinct mechanical constraints.

Availability

TLVH431AQDCKT is available at Aetrix Electronics and suitable for isolated power supplies, precision analog monitoring, and low-voltage comparator circuits requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for TLVH431AQDCKT 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.

The TLVH431 family was engineered for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications-including automotive power supplies, industrial sensors, and portable medical devices.

FAQ

What is the reference voltage tolerance of TLVH431AQDCKT at 25°C?

The TLVH431AQDCKT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal V_REF with a range of 1.234 V to 1.246 V. This A-grade tolerance is confirmed in Section 5.6 of the TI SLVS555N datasheet and applies specifically to the 'AQ' suffix variant in SC-70 packaging. TLVH431AQDCKT maintains this accuracy across its full operating temperature range with specified drift limits.

Can TLVH431AQDCKT replace a standard Zener diode in low-leakage applications?

Yes, TLVH431AQDCKT replaces low-voltage Zener diodes with superior performance: it delivers 1.24 V reference voltage with ±0.5% tolerance, <0.1 μA off-state cathode current at 18 V, and 0.25 Ω dynamic impedance-far lower leakage and tighter regulation than typical Zeners. Its SC-70 package also enables higher-density layouts. TLVH431AQDCKT is explicitly positioned as a Zener replacement in TI's official Applications section.

What is the minimum cathode current required for regulation in TLVH431AQDCKT?

The TLVH431AQDCKT requires a minimum cathode current of 100 μA to maintain regulation, as specified in Section 5.5 (IK(min)) of the datasheet. This value is guaranteed over the full –40°C to +125°C temperature range. Operation below 100 μA may result in insufficient gain and unstable regulation. TLVH431AQDCKT's low IK(min) enables use in ultra-low-power systems where traditional TL431 (1 mA min) cannot function.

Does TLVH431AQDCKT require an output capacitor for stability?

No, TLVH431AQDCKT is internally compensated and stable without an output capacitor between cathode and anode-unlike many linear regulators. TI confirms this in Section 7.3, stating it "is internally compensated to be stable without an output capacitor." Capacitors may be added for noise filtering or phase-margin tuning in specific high-capacitive-load scenarios, but they are not required for basic regulation stability. TLVH431AQDCKT's architecture eliminates this design constraint.

How does the SC-70 package of TLVH431AQDCKT compare to SOT-23 variants?

The TLVH431AQDCKT SC-70 package measures 2.00 mm × 1.25 mm-40% smaller than the SOT-23-3 footprint-enabling higher board density in compact designs. It uses a 6-pin configuration (CATHODE–ANODE–REF–NC–NC–ANODE) with Pin 2 designated as substrate connection, requiring tie to ANODE (Pin 6). This differs from SOT-23 variants like TLVH432AQDBZR, which use 3-pin REF–ANODE–CATHODE layout and are not mechanically or electrically interchangeable with TLVH431AQDCKT.