Texas Instruments TLVH431QDCKR

Overview

TLVH431QDCKR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SC-70 package, providing 1.24 V reference voltage with ±0.5% initial tolerance (B-grade), 100 μA to 70 mA cathode current range, and operation from –40°C to +125°C. It functions as an error amplifier or comparator with integrated reference in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431QDCKR datasheet, TLVH431QDCKR pinout, TLVH431QDCKR application, or TLVH431QDCKR equivalent, key selection criteria include reference accuracy at temperature extremes, dynamic impedance (0.25 Ω), minimum cathode current (100 μA), and SC-70 footprint suitability for space-constrained power rail monitoring and secondary-side regulation.

Technical Context

The TLVH431QDCKR implements a precision bandgap reference (1.24 V) paired with a high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop configuration enables comparator operation with built-in threshold; closed-loop use with external resistors sets output voltage from 1.24 V to 18 V.

It operates down to 1.24 V cathode-anode voltage, requires ≥100 μA cathode current for regulation, and maintains 0.25 Ω typical dynamic impedance across 0.1 mA–70 mA. Internal compensation ensures stability without output capacitance, though phase margin vs. capacitive load is characterized up to 100 nF.

Key Specifications

Pinout & Package

TLVH431QDCKR uses the 6-pin SC-70 (DCK) package (2.00 mm × 1.25 mm), with pin 1 = CATHODE, pin 2 = NC (no internal connection), pin 3 = REF, pin 4 = NC, pin 5 = ANODE, pin 6 = substrate connection (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 TLVH431CDCKR and TLVH431IDCKR, TLVH431QDCKR delivers the tightest initial accuracy (±0.5%), widest temperature range (–40°C to +125°C), and lowest dynamic impedance - making it the sole choice for automotive AEC-Q100-aligned designs requiring long-term stability under thermal stress.

Availability

TLVH431QDCKR is available at Aetrix Electronics and suitable for isolated SMPS feedback, voltage rail monitoring, precision data converter references, and low-leakage Zener replacement applications requiring stable component supply across automotive and industrial production cycles.

Supply support for TLVH431QDCKR 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 optimized for secondary-side regulation in isolated power supplies and compact voltage monitoring in space- and power-constrained systems.

FAQ

What is the reference voltage tolerance of TLVH431QDCKR at 25°C?

The TLVH431QDCKR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value ranging from 1.234 V to 1.246 V. This B-grade specification is confirmed in Section 5.7 of the TI datasheet SLVS555N and applies specifically to the Q-temperature variant. The tolerance remains valid across the full –40°C to +125°C operating range as a maximum deviation of ±31 mV.

Can TLVH431QDCKR operate with cathode current below 100 μA?

No - TLVH431QDCKR requires a minimum cathode current of 100 μA to maintain regulation and specified reference accuracy. Below this threshold, open-loop gain drops significantly, causing degraded line/load regulation and increased VREF deviation. The datasheet specifies IK(min) = 100 μA (max) across temperature, and operation at 60 μA is only guaranteed for non-regulated comparator mode, not shunt reference operation.

How does the SC-70 package of TLVH431QDCKR differ from SOT-23 variants?

The TLVH431QDCKR uses a 6-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm - 40% smaller than the 3-pin SOT-23-3 (DBZ) variant. Unlike DBZ, DCK exposes two NC pins and a dedicated substrate terminal (pin 6), which must be connected to ANODE or left floating. Pinout differs: DCK assigns CATHODE to pin 1 and REF to pin 3, while DBZ places REF on pin 1 and CATHODE on pin 2.

Does TLVH431QDCKR require an output capacitor for stability?

No - TLVH431QDCKR is internally compensated and stable without an output capacitor between CATHODE and ANODE. This eliminates capacitor-related failure modes and simplifies layout. However, if external capacitance is added (e.g., for noise filtering), Figure 5-15 through 5-17 in the datasheet provide phase margin vs. capacitive load curves up to 100 nF to guide selection and avoid oscillation.

What is the maximum cathode voltage rating for TLVH431QDCKR?

The absolute maximum cathode voltage (VKA) for TLVH431QDCKR is 20 V, defined as the voltage at the CATHODE pin relative to the ANODE pin. In normal operation, the recommended maximum is 18 V (per Section 5.3). Exceeding 20 V risks permanent damage, and operation above 18 V degrades long-term reliability even if within absolute ratings.