Texas Instruments TLVH431BIDCKR

Overview

TLVH431BIDCKR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SC-70-6 package, featuring 1.24 V reference voltage (±0.5% at 25°C), 100 μA to 70 mA cathode current range, 0.25 Ω typical dynamic impedance, and operation from –40°C to +125°C. It serves as an ultra-low-voltage Zener replacement and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431BIDCKR datasheet, TLVH431BIDCKR pinout, TLVH431BIDCKR application, or TLVH431BIDCKR equivalent, key selection criteria include reference accuracy grade (B), SC-70 footprint constraints, cathode current headroom for regulation stability, and compatibility with optocoupler-based secondary-side control in 3.3 V systems.

Technical Context

The TLVH431BIDCKR implements a bandgap-referenced error amplifier with Darlington output stage, enabling precise shunt regulation down to 1.24 V - 1.26 V lower than TL431. Its internal architecture supports both open-loop comparator operation (with integrated 1.24 V threshold) and closed-loop shunt regulation via external resistor divider.

Unlike standard shunt references, it achieves stable operation without mandatory output capacitance due to internal compensation, while maintaining sharp turn-on characteristics and low temperature drift (≤31 mV over –40°C to +125°C for Q-grade variants). The SC-70-6 package includes dedicated NC and substrate pins requiring connection to ANODE per layout guidance.

Key Specifications

Pinout & Package

TLVH431BIDCKR uses the SC-70-6 (DCK) package (2.00 mm × 1.25 mm), with pin 2 internally connected to substrate and requiring connection to ANODE or left open per TI layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431BIDCKR, TLVH431BIDBVR offers better thermal performance in space-constrained layouts, while TLVH431BQDBZR trades miniaturization for mechanical robustness and through-hole compatibility - neither is pin-compatible, but all share identical functional behavior and B-grade reference accuracy.

Availability

TLVH431BIDCKR is available at Aetrix Electronics and suitable for isolated flyback SMPS design, precision data converter reference generation, and low-power voltage monitoring applications requiring stable component supply and guaranteed long-term sourcing.

Supply support for TLVH431BIDCKR 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 delivering analog and embedded processing solutions, with leadership in precision analog ICs and power management.

The TLVH431 family was designed specifically for low-voltage shunt regulation in isolated power supplies and precision reference applications, extending the TL431 architecture to sub-2 V operating domains with improved thermal stability and smaller packaging.

FAQ

What is the reference voltage tolerance of TLVH431BIDCKR at 25°C?

The TLVH431BIDCKR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value with a range of 1.234 V to 1.246 V. This B-grade accuracy is specified in Section 5.7 of the TI datasheet and directly impacts feedback divider design margin in regulated power supplies. TLVH431BIDCKR maintains this tolerance across its full operating temperature range with controlled drift.

Can TLVH431BIDCKR replace a standard Zener diode in low-current applications?

Yes, TLVH431BIDCKR is explicitly designed as a low-leakage Zener replacement, offering 0.02–0.1 μA off-state cathode current versus typical Zener leakage of >1 μA. Its 100 μA minimum cathode current requirement and 0.25 Ω dynamic impedance provide superior regulation accuracy and stability compared to discrete Zeners, especially below 3.3 V. TLVH431BIDCKR also integrates a precision reference, eliminating external voltage references in comparator configurations.

What is the correct connection for Pin 2 (substrate) on TLVH431BIDCKR?

Pin 2 of TLVH431BIDCKR is internally connected to the silicon substrate and must be connected to the ANODE terminal or left electrically floating - it must never be connected to CATHODE or REF. This requirement is documented in TI's Pin Functions table and Figure 4-2. Improper connection risks thermal instability and ESD susceptibility. TLVH431BIDCKR's SC-70 layout guidelines specify this tie to maintain specified R_θJC and reliability.

Does TLVH431BIDCKR require an output capacitor for stability?

No, TLVH431BIDCKR is internally compensated and operates stably without an output capacitor between CATHODE and ANODE - a key advantage over many linear regulators. However, if an output capacitor is added for noise filtering or transient response enhancement, Figures 5-15 to 5-17 in the TI datasheet provide phase-margin guidance for selecting values up to 100 nF depending on cathode voltage. TLVH431BIDCKR's stability is verified across its full 100 μA–70 mA cathode current range.

How does TLVH431BIDCKR differ from TL431 in low-voltage operation?

TLVH431BIDCKR operates down to 1.24 V reference voltage and 100 μA minimum cathode current, whereas TL431 requires ≥2.5 V reference and ≥1 mA cathode current. This 1.26 V lower headroom and 10× lower current threshold enable TLVH431BIDCKR to regulate in 1.8 V and 2.5 V systems where TL431 fails. Both share functional equivalence as shunt regulators, but TLVH431BIDCKR's architecture targets modern low-voltage power architectures - confirmed by TI's direct comparison in Section 7.1 of the datasheet.