Texas Instruments TLV431BCDBVT

Overview

TLV431BCDBVT from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage - used as an error amplifier or voltage reference in isolated flyback SMPS feedback loops.

For engineers reviewing the TLV431BCDBVT datasheet, TLV431BCDBVT pinout, TLV431BCDBVT application, or TLV431BCDBVT equivalent, key selection considerations include reference accuracy over temperature (±4 mV from 0°C to 70°C), ultra-low 80 µA typical cathode current for regulation, SC-70 package footprint (2.0 mm × 1.5 mm), and compatibility with optocoupler-based secondary-side regulation in 3.3 V systems.

Technical Context

The TLV431BCDBVT implements a bandgap-referenced error amplifier with Darlington sink output, operating in open-loop comparator mode or closed-loop shunt regulation depending on external feedback configuration. Its internal reference is trimmed to 1.24 V with 0.5% tolerance, and it achieves stable regulation with ≥55 µA minimum cathode current across 0°C to 70°C.

Unlike the TL431, the TLV431BCDBVT supports lower headroom (VKA ≥ 1.24 V) and lower IK(min), enabling use in 3 V–3.3 V input systems. It requires no external compensation capacitor and maintains stability with capacitive loads up to 1 nF, per phase-margin characterization at 1.25 V, 2.5 V, and 5 V VKA.

Key Specifications

Pinout & Package

TLV431BCDBVT uses the SC-70 (DCK) 6-pin package with 2.0 mm × 1.5 mm body size and gull-wing leads. Pin 1 is CATHODE, Pin 3 is REFERENCE, Pin 6 is ANODE; Pins 2, 4, and 5 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BCDBVT, TLV431ACDBVT trades 0.5% accuracy for lower unit cost while retaining identical thermal drift and package, whereas TLVH431IDBVR expands voltage and current capability but requires different PCB layout and lacks NC pins - making TLV431BCDBVT optimal for high-accuracy, space-constrained 3.3 V flyback regulation.

Availability

TLV431BCDBVT is available at Aetrix Electronics and suitable for isolated SMPS feedback, precision voltage monitoring, and low-power comparator applications requiring stable component supply, long-term manufacturability, and TI-qualified automotive-grade variants.

Supply support for TLV431BCDBVT 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, power management, and signal chain technologies.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained power systems - targeting 3 V–3.3 V isolated DC/DC converters, battery supervision, and reference replacement in industrial and computing equipment.

FAQ

What is the reference voltage tolerance of TLV431BCDBVT at 25°C?

The TLV431BCDBVT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a VREF range of 1.234 V to 1.246 V. This tight tolerance is specified in Section 5.7 of the TI datasheet SLVS139Z and applies only to the 'B' grade variant. The TLV431BCDBVT maintains this accuracy across its commercial temperature range (0°C to 70°C) with ±4 mV total drift.

Can TLV431BCDBVT operate with a cathode-anode voltage below 2.5 V?

Yes, TLV431BCDBVT is explicitly designed for low-voltage operation and functions down to VKA = 1.24 V - the value of its internal reference voltage. This enables direct use in 3.3 V and even 2.5 V systems without pre-regulation, unlike the TL431 which requires ≥2.5 V headroom. The datasheet confirms stable regulation begins at 1.24 V with ≥55 µA cathode current.

What package type does TLV431BCDBVT use, and what are its dimensions?

TLV431BCDBVT uses the SC-70 (DCK) package, a 6-pin gull-wing surface-mount outline measuring 2.0 mm × 1.5 mm (nominal body size). This is 40% smaller than the standard SOT-23-3 footprint. Pin 1 is CATHODE, Pin 3 is REFERENCE, Pin 6 is ANODE; Pins 2, 4, and 5 are NC and must remain unconnected unless tied to ANODE per TI guidance.

How does TLV431BCDBVT differ from TLV431ACDBVT?

TLV431BCDBVT and TLV431ACDBVT share identical package (SC-70), pinout, dynamic impedance (0.25 Ω), and temperature drift (±4 mV over 0°C–70°C), but differ in reference voltage tolerance: TLV431BCDBVT is ±0.5% at 25°C, while TLV431ACDBVT is ±1%. Both are drop-in replacements in layout, but TLV431BCDBVT provides higher accuracy for precision feedback or monitoring applications.

Is an external capacitor required for stability with TLV431BCDBVT?

No, TLV431BCDBVT is internally compensated and remains stable without an external output capacitor between CATHODE and ANODE. Figure 5-19 in the datasheet shows phase margin remains >45° for capacitive loads up to 1 nF at VKA = 1.25 V. An external capacitor is optional and only needed if additional filtering or transient suppression is required beyond the device's native stability.