Texas Instruments TLV431ACDBVRE4

Overview

TLV431ACDBVRE4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C, and operation from 1.24 V to 6 V output range. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and supports secondary-side regulation in isolated flyback SMPSs powering 3.3 V systems.

For engineers reviewing the TLV431ACDBVRE4 datasheet, TLV431ACDBVRE4 pinout, TLV431ACDBVRE4 application, or TLV431ACDBVRE4 equivalent, key selection considerations include reference accuracy over temperature (±4 mV from 0°C to 70°C), ultra-small SC-70 package footprint, open-loop comparator capability with integrated reference, and compatibility with optocoupler-based feedback loops in compact power supplies.

Technical Context

The TLV431ACDBVRE4 implements a three-terminal adjustable shunt reference architecture with an internal bandgap reference and high-gain NPN-based error amplifier. Its functional modes include closed-loop regulation (shunt regulator or error amplifier) and open-loop comparator operation-both enabled by the same reference and sink-current output stage.

It operates with cathode-to-anode voltage (VKA) as low as 1.24 V and requires ≥55 µA cathode current for regulation across its full industrial temperature range (–40°C to 85°C). The device is internally compensated and stable without external output capacitance, though phase margin vs. capacitive load is characterized up to 1 nF for design validation.

Key Specifications

Pinout & Package

TLV431ACDBVRE4 is housed in a 6-pin SC-70 (DCK) package with exposed substrate connection. Pin 2 (substrate) must be connected to ANODE or left floating per TI specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431BCDBVR, TLV431ACDBVRE4 trades 0.5% reference accuracy for lower unit cost and broader availability; compared with TLVH431ACDBVR, it offers smaller SC-70 footprint and lower quiescent current but limits maximum cathode voltage to 6 V and current to 15 mA.

Availability

TLV431ACDBVRE4 is available at Aetrix Electronics and suitable for isolated flyback SMPS feedback, overvoltage protection circuits, and programmable current sink designs requiring stable component supply and long-term manufacturability.

Supply support for TLV431ACDBVRE4 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, embedded processing, and power management technologies, with decades of leadership in precision reference and power IC design.

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, voltage monitors, and programmable references in consumer, industrial, and telecom systems.

FAQ

What is the reference voltage tolerance of TLV431ACDBVRE4 at 25°C?

The TLV431ACDBVRE4 has a reference voltage tolerance of ±1% at 25°C, meaning its VREF is guaranteed between 1.228 V and 1.252 V under nominal conditions. This tolerance is confirmed in Section 5.6 of the TI datasheet SLVS139Z and applies specifically to the 'A' grade variant in the SC-70 package. The TLV431ACDBVRE4 maintains this specification across its rated operating temperature range of –40°C to 85°C.

Can TLV431ACDBVRE4 replace TL431 in existing designs?

TLV431ACDBVRE4 is not a direct pin-compatible replacement for TL431 due to different pin count (6-pin SC-70 vs. 3-pin TO-92/SOT-23) and lower reference voltage (1.24 V vs. 2.5 V). However, it can functionally replace TL431 in low-voltage applications (<6 V) where board layout allows SC-70 placement and feedback network is reconfigured for 1.24 V reference. The TLV431ACDBVRE4 requires ≥55 µA cathode current versus TL431's 1 mA minimum.

What is the minimum cathode current required for regulation in TLV431ACDBVRE4?

The TLV431ACDBVRE4 requires a minimum cathode current (IK(min)) of 55 µA to 80 µA depending on temperature - 55 µA at 25°C and up to 80 µA across the full –40°C to 85°C range. This value is specified in Section 5.6 of the TI datasheet and reflects the lowest current needed to maintain regulation accuracy and gain. Operating below this threshold risks degraded reference stability and slow response in TLV431ACDBVRE4.

Does TLV431ACDBVRE4 require an external output capacitor for stability?

No, TLV431ACDBVRE4 is internally compensated and stable without an external output capacitor between CATHODE and ANODE. TI's datasheet confirms this in Section 7.3 and provides phase margin vs. capacitive load curves (Figures 5-19 to 5-21) for cases where designers choose to add one - e.g., to filter noise or improve transient response. Adding capacitance beyond 1 nF may reduce phase margin, so TLV431ACDBVRE4 stability must be verified per application conditions.

How does the SC-70 package of TLV431ACDBVRE4 compare to SOT-23-3 variants?

The SC-70 (DCK) package of TLV431ACDBVRE4 measures 2.0 mm × 1.5 mm - approximately 40% smaller than the SOT-23-3 footprint (2.92 mm × 2.37 mm) used by TLV431ACDBZR. While both offer 3 active terminals (CATHODE, REF, ANODE), the SC-70 adds two NC pins and a substrate pin (Pin 2), requiring explicit handling per TI's pin-function table. TLV431ACDBVRE4's SC-70 enables higher-density layouts but demands updated land patterns and assembly validation.