Texas Instruments TLVH431AQDBVR

Overview

TLVH431AQDBVR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance at 25°C (A-grade), 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. It serves as a Zener replacement and error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431AQDBVR datasheet, TLVH431AQDBVR pinout, TLVH431AQDBVR application, or TLVH431AQDBVR equivalent, key selection criteria include reference accuracy over –40°C to +125°C, ultra-low minimum cathode current for low-power regulation, SC-70 package footprint constraints, and compatibility with optocoupler-based secondary-side control architectures.

Technical Context

The TLVH431AQDBVR implements a precision bandgap reference and high-gain transconductance amplifier in a single 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 open-loop comparator mode or closed-loop shunt regulator mode depending on feedback configuration.

It achieves thermal stability across –40°C to +125°C (Q-grade) with 11 mV max VREF deviation over temperature and <0.5 µA reference terminal current. Its 0.25 Ω dynamic impedance and 1.24 V reference enable accurate voltage monitoring and low-headroom regulation in 3.3 V and lower systems.

Key Specifications

Pinout & Package

TLVH431AQDBVR is packaged in a 6-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm, offering a 40% smaller footprint than SOT-23-3. The package includes two NC pins and substrate connection tied to ANODE.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AQDBVR, TLVH431BQDBVR offers identical performance with tighter factory binning, while TLV431ACDBVR trades accuracy and temperature range for lower unit cost - both require no PCB changes but differ in qualification scope and long-term stability.

Availability

TLVH431AQDBVR is available at Aetrix Electronics and suitable for isolated power supplies, precision data acquisition systems, and automotive body electronics requiring stable component supply across extended temperature ranges.

Supply support for TLVH431AQDBVR 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 delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications - including secondary-side feedback in compact flyback converters and precision voltage monitoring in automotive ECUs.

FAQ

What is the reference voltage tolerance of TLVH431AQDBVR at 25°C?

The TLVH431AQDBVR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal VREF ranging from 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. TLVH431AQDBVR maintains this accuracy across its full operating temperature range with ≤31 mV total deviation.

Does TLVH431AQDBVR require an external output capacitor for stability?

No, TLVH431AQDBVR is internally compensated and remains stable without an external capacitor between CATHODE and ANODE. Section 7.3 of the datasheet explicitly states this feature, enabling simplified layout in isolated feedback circuits. However, if a capacitor is added for noise filtering, Figures 5-15 through 5-17 provide phase-margin guidance versus capacitive load for TLVH431AQDBVR at various cathode voltages.

What is the minimum cathode current needed for regulation in TLVH431AQDBVR?

The minimum cathode current required for regulation in TLVH431AQDBVR is 100 µA, as specified in Sections 5.5–5.7 under IK(min) for all grades. This value holds across the full –40°C to +125°C temperature range. Operating below this current may result in insufficient open-loop gain and unstable regulation behavior in TLVH431AQDBVR.

How does the SC-70 package of TLVH431AQDBVR compare to SOT-23-3 in size?

The TLVH431AQDBVR SC-70 (DCK) package measures 2.00 mm × 1.25 mm, which is 40% smaller in footprint than the standard SOT-23-3 package (2.92 mm × 1.30 mm). This reduction supports high-density PCB layouts in portable and automotive modules. Pin count differs (6-pin SC-70 vs 3-pin SOT-23), but the functional CATHODE/ANODE/REF terminals occupy identical relative positions per Figure 4-2 in the datasheet.

Can TLVH431AQDBVR be used as a comparator with integrated reference?

Yes, TLVH431AQDBVR functions as a comparator in open-loop configuration: when the REF pin voltage exceeds 1.24 V, the CATHODE sinks current, producing a digital-like output transition. Section 7.4.1 and Figure 8-2 confirm this use case. Its 0.1–0.5 µA REF input current and >100 dB open-loop gain make TLVH431AQDBVR suitable for rail monitoring and threshold detection without external components.