Texas Instruments TLV431ACDBVTE4

Overview

TLV431ACDBVTE4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage. It functions as an integrated voltage reference and error amplifier in isolated flyback SMPS feedback loops for 3.3 V systems.

For engineers reviewing the TLV431ACDBVTE4 datasheet, TLV431ACDBVTE4 pinout, TLV431ACDBVTE4 application, or TLV431ACDBVTE4 equivalent, key selection considerations include its SC-70 (DCK) package footprint, 80 µA typical minimum cathode current, 4 mV max VREF drift over 0°C to 70°C, and compatibility with optocoupler-based secondary-side regulation.

Technical Context

The TLV431ACDBVTE4 implements a bandgap-referenced transconductance amplifier driving a Darlington sink output stage. Its internal reference is trimmed to 1.24 V with 1% accuracy at 25°C and exhibits 4 mV total deviation across 0°C to 70°C ambient. The device operates in two distinct functional modes: open-loop comparator (with integrated 1.24 V threshold) and closed-loop shunt regulator (using external resistor divider feedback from cathode to reference pin).

In closed-loop configuration, it regulates output voltage VO = VREF × (1 + R1/R2) + Iref × R1, where Iref ≤ 0.5 µA ensures minimal loading error. Stability is internally compensated-no output capacitor required-but phase margin degrades with capacitive loads > 1 nF, requiring careful selection per Figure 5-19–5-21.

Key Specifications

Pinout & Package

TLV431ACDBVTE4 is packaged in ultra-small SC-70 (DCK), measuring 2.0 mm × 1.5 mm with 6 terminals. This 40% smaller footprint than SOT-23-3 enables high-density PCB layouts in space-constrained power modules and portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BIDCKR, TLV431ACDBVTE4 trades 0.5% accuracy for lower unit cost and identical thermal performance; compared with TLVH431ACDBVR, it offers smaller SC-70 size and lower quiescent current but limits maximum regulated voltage to 6 V.

Availability

TLV431ACDBVTE4 is available at Aetrix Electronics and suitable for isolated flyback SMPS regulation, Zener diode replacement, comparator circuits with integrated reference, voltage monitoring, and adjustable current referencing requiring stable component supply across production lifecycles.

Supply support for TLV431ACDBVTE4 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 power management, signal chain, and high-reliability components.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained and energy-efficient applications-including isolated DC/DC converters, battery monitors, and precision comparators-where traditional TL431 devices cannot operate.

FAQ

What is the reference voltage tolerance of TLV431ACDBVTE4 at 25°C?

The TLV431ACDBVTE4 has a reference voltage tolerance of ±1% at 25°C, meaning its VREF is guaranteed between 1.228 V and 1.252 V under those conditions. This tolerance is specified in Section 5.6 of the TI datasheet SLVS139Z and applies exclusively to the 'A' grade variant. The 'C' suffix indicates commercial temperature range (0°C to 70°C), and the 'DBVT' package code confirms SC-70 (DCK) packaging.

Can TLV431ACDBVTE4 regulate output voltages below 3.3 V?

Yes, TLV431ACDBVTE4 can regulate output voltages as low as 1.24 V-the value of its internal reference-making it suitable for 1.8 V, 2.5 V, and 3.3 V rails. Unlike the TL431 (2.5 V reference), its 1.24 V baseline enables regulation in modern low-voltage systems. The minimum cathode-anode voltage (VKA) must remain ≥1.24 V, and sufficient cathode current (≥80 µA) must be supplied for stable operation.

What package type does TLV431ACDBVTE4 use, and how many pins does it have?

TLV431ACDBVTE4 uses the SC-70 package (also designated DCK), which is a 6-pin surface-mount package measuring 2.0 mm × 1.5 mm. Pin assignments are: Pin 1 = CATHODE, Pin 3 = REF, Pin 6 = ANODE, Pins 4 and 5 = NC, and Pin 2 = Substrate (to be tied to ANODE or left floating). This ultra-compact footprint is 40% smaller than SOT-23-3 and optimized for high-density PCBs.

How does TLV431ACDBVTE4 behave in open-loop versus closed-loop configurations?

In open-loop mode, TLV431ACDBVTE4 acts as a comparator with integrated 1.24 V reference-output switches sharply when REF voltage crosses VREF. In closed-loop mode, feedback from CATHODE to REF forms a shunt regulator, adjusting sink current to hold VO = VREF × (1 + R1/R2) + Iref × R1. Both modes require ≥80 µA cathode current; open-loop demands ≥10% overdrive for fast response, while closed-loop relies on resistor ratio accuracy.

Is an output capacitor required for stability with TLV431ACDBVTE4?

No, TLV431ACDBVTE4 is internally compensated and stable without an output capacitor between CATHODE and ANODE. However, adding capacitance >1 nF degrades phase margin-Figure 5-19 shows stability boundaries up to ~1 nF at VKA = 1.25 V. If external capacitance is needed (e.g., for noise filtering), select values ≤1 nF and verify stability per TI's SLUA671 application note on compensation design.