Texas Instruments TLVH431AQDBVT

Overview

TLVH431AQDBVT 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 functions as a programmable voltage reference or error amplifier in isolated feedback loops, especially in 3.3 V flyback SMPS secondary-side regulation.

For engineers reviewing the TLVH431AQDBVT datasheet, TLVH431AQDBVT pinout, TLVH431AQDBVT application, or TLVH431AQDBVT equivalent, key selection criteria include its 1.24 V minimum output setting, ultra-low 0.5% reference tolerance, –40°C to +125°C Q-grade temperature range, and SC-70-6 package compatibility with space-constrained power management designs.

Technical Context

The TLVH431AQDBVT implements a high-gain NPN-based error amplifier with an internal 1.24 V bandgap reference, enabling precise closed-loop shunt regulation or open-loop comparator operation. Its Darlington output stage delivers sharp turn-on characteristics and supports cathode currents from 100 µA to 70 mA.

Unlike the TL431, it operates at lower headroom (≥1.24 V) and draws sub-1 µA reference input current, making it suitable for low-power, wide-input-range applications including Zener replacement and on-board rail monitoring where thermal stability and leakage minimization are critical.

Key Specifications

Pinout & Package

TLVH431AQDBVT is packaged in a 6-pin SC-70 (DCK) with nominal body size 2.00 mm × 1.25 mm, offering 40% smaller footprint than SOT-23-3 while maintaining thermal performance (R_θJA = 259°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AQDBVT, TLVH431BQDBVT offers superior thermal stability for metrology-grade references, while TLV431ACDBVR trades accuracy and qualification for lower unit cost in commercial-grade power management - neither is pin-compatible, requiring PCB redesign for substitution.

Availability

TLVH431AQDBVT is available at Aetrix Electronics and suitable for automotive power management, industrial SMPS design, and precision analog reference applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TLVH431AQDBVT 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 ICs, with decades of expertise in precision reference and power control technologies.

The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in isolated and non-isolated power supplies, data converters, and voltage-monitoring systems demanding robustness across automotive and industrial temperature grades.

FAQ

What is the reference voltage tolerance of TLVH431AQDBVT at 25°C?

The TLVH431AQDBVT 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 specification is confirmed in Section 5.6 of the official TI datasheet SLVS555N and applies specifically to the AQ variant in the SC-70 package. The TLVH431AQDBVT maintains this tight tolerance across its full operating temperature range of –40°C to +125°C.

Can TLVH431AQDBVT replace a standard Zener diode in low-power applications?

Yes, TLVH431AQDBVT is explicitly designed as a low-leakage, adjustable Zener replacement. With off-state cathode current ≤0.1 µA at 18 V and operation down to 100 µA cathode current, it delivers significantly lower leakage than typical Zeners-especially above 85°C-while enabling precise voltage setting from 1.24 V to 18 V using two resistors. Its sharp turn-on and 0.25 Ω dynamic impedance make TLVH431AQDBVT ideal for on-board regulation where Zener accuracy and thermal drift are problematic.

What is the minimum cathode current required for regulation in TLVH431AQDBVT?

The minimum cathode current required for regulation in TLVH431AQDBVT is 100 µA, as specified in Sections 5.5–5.7 of the TI datasheet under I_K(min). This value holds across the full –40°C to +125°C temperature range. Below this threshold, the internal amplifier may exit linear region, causing loss of regulation accuracy and increased output impedance. Designers must ensure external biasing or load current guarantees ≥100 µA into the cathode pin under all operating conditions for stable TLVH431AQDBVT performance.

Does TLVH431AQDBVT require an output capacitor for stability?

No, TLVH431AQDBVT is internally compensated and does not require an output capacitor between cathode and anode for basic stability in shunt regulator configurations. This is confirmed in Section 7.3 of the datasheet. However, if an output capacitor is used-such as for noise filtering or transient suppression-Figures 5-15 through 5-17 provide phase-margin guidance versus capacitive load. TLVH431AQDBVT's stability margin remains sufficient up to ~10 nF at V_KA = 5 V, but larger values may require series resistance or careful layout to maintain loop integrity.

How does the SC-70-6 package of TLVH431AQDBVT compare thermally to SOT-23 variants?

The SC-70-6 package of TLVH431AQDBVT has a junction-to-ambient thermal resistance (R_θJA) of 259°C/W, which is higher than the 206°C/W of the SOT-23-5 (DBV) and 140°C/W of the TO-92 (LP) packages. This reflects its smaller footprint (2.00 mm × 1.25 mm). However, its junction-to-case (top) thermal resistance is 87°C/W, enabling effective heat transfer to PCB copper when properly soldered. For TLVH431AQDBVT, thermal design must prioritize adequate copper pour and minimize power dissipation (P_D ≤ (125°C − T_A)/259) to stay within safe operating limits.