Texas Instruments TLVH431CDCKR

Overview

TLVH431CDCKR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SC-70 package, functioning as a 1.24 V reference with ±0.5% initial tolerance (B-grade), 100 μA to 70 mA cathode current range, and 0.25 Ω typical dynamic impedance. It enables precise voltage regulation down to 1.24 V in isolated flyback SMPS feedback loops and serves as a low-leakage Zener replacement in space-constrained power rails.

For engineers reviewing the TLVH431CDCKR datasheet, TLVH431CDCKR pinout, TLVH431CDCKR application, or TLVH431CDCKR equivalent, key selection criteria include its SC-70 footprint, 1.24 V reference accuracy at 25°C, –40°C to +125°C operation, cathode current headroom for optocoupler-driven feedback, and compatibility with resistor-based output voltage adjustment from VREF to 18 V.

Technical Context

The TLVH431CDCKR implements a bandgap-referenced error amplifier with internal 1.24 V reference and Darlington output stage, operating in either open-loop comparator mode or closed-loop shunt regulation. Its design supports stable operation without external compensation capacitors across its full 100 μA–70 mA cathode current range.

It achieves sharp turn-on characteristics via active output circuitry and maintains thermal stability over industrial and automotive temperature ranges. The device requires ≥100 μA cathode current to enter linear regulation and draws only 0.1–0.5 μA reference terminal current, enabling high-impedance feedback networks.

Key Specifications

Pinout & Package

TLVH431CDCKR uses the 6-pin SC-70 (DCK) package (2.00 mm × 1.25 mm), with pins 1 and 6 as CATHODE and ANODE respectively, pin 3 as REF, and pins 2, 4, and 5 as NC (no internal connection). Pin 2 connects to substrate and 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 TLVH431ACDCKR, TLVH431CDCKR delivers tighter reference accuracy for precision feedback loops; compared with TLVH432CDCKR, it retains legacy pinout compatibility for drop-in upgrades in existing SC-70 layouts without netlist or footprint changes.

Availability

TLVH431CDCKR is available at Aetrix Electronics and suitable for isolated power supplies, battery management systems, industrial sensor interfaces, and embedded voltage monitoring requiring stable component supply across automotive and extended-temperature applications.

Supply support for TLVH431CDCKR 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 TLVH431 product line delivers low-voltage, high-accuracy shunt references for space- and power-constrained applications including isolated DC/DC converters, portable instrumentation, and automotive body electronics.

FAQ

What is the reference voltage tolerance of TLVH431CDCKR at 25°C?

The TLVH431CDCKR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal V_REF with min/max bounds of 1.234 V and 1.246 V. This B-grade specification is confirmed in Section 5.7 of the TI datasheet SLVS555N and applies specifically to the TLVH431CDCKR variant. The tolerance remains stable across its rated temperature range, with total deviation limited to ±31 mV from –40°C to +125°C.

Can TLVH431CDCKR operate with cathode current below 100 μA?

No - TLVH431CDCKR requires a minimum cathode current of 100 μA to maintain regulation and specified dynamic impedance. Below this threshold, gain drops significantly, causing poor line/load regulation and increased output impedance. The datasheet specifies IK(min) = 100 μA (max) at 25°C, rising to 120 μA at 125°C. For ultra-low-current applications, TLVH431CDCKR must be biased above this floor using appropriate resistor networks or auxiliary current sources.

What is the correct pin configuration for TLVH431CDCKR in SC-70 package?

TLVH431CDCKR uses the 6-pin SC-70 (DCK) package with pin 1 = CATHODE, pin 2 = NC (substrate, tie to ANODE or leave open), pin 3 = REF, pin 4 = NC, pin 5 = NC, and pin 6 = ANODE. This configuration is explicitly defined in Figure 4-2 and the Pin Functions table of the SLVS555N datasheet. Misidentifying pin 3 as ANODE or omitting the substrate tie on pin 2 will result in functional failure or instability.

How does TLVH431CDCKR differ from TLVH432CDCKR?

TLVH431CDCKR and TLVH432CDCKR share identical electrical specifications and SC-70 packaging but differ in pinout: TLVH431CDCKR uses a 6-pin arrangement (CATHODE–NC–REF–NC–NC–ANODE), while TLVH432CDCKR uses a 3-pin variant (REF–CATHODE–ANODE) in the same SC-70 body. The TLVH432 variant simplifies routing but is not pin-compatible - using it requires PCB redesign. Both are functionally interchangeable when layout permits.

Is an output capacitor required for stability with TLVH431CDCKR?

No - TLVH431CDCKR is internally compensated and operates stably without an output capacitor between cathode and anode. This is confirmed in Section 7.3 of the datasheet. However, if a capacitor is added for EMI filtering or transient response enhancement, Figures 5-15 to 5-17 provide phase-margin guidance versus capacitive load. Unnecessary capacitors may degrade step response or introduce peaking; TLVH431CDCKR's 0.25 Ω dynamic impedance inherently provides robust regulation without external stabilization.