Texas Instruments TLV431CDBVTE4

Overview

TLV431CDBVTE4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and operation from 1.24 V to 6 V output range - used as an integrated reference in isolated flyback secondary-side regulation and low-voltage Zener replacement circuits.

For engineers reviewing the TLV431CDBVTE4 datasheet, TLV431CDBVTE4 pinout, TLV431CDBVTE4 application, or TLV431CDBVTE4 equivalent, key selection considerations include reference accuracy over 0°C to 70°C, SC-70 package footprint constraints, cathode current requirements for stable regulation, and compatibility with optocoupler-based feedback in 3.3 V SMPS designs.

Technical Context

The TLV431CDBVTE4 implements a bandgap-referenced error amplifier driving a Darlington sink output stage, enabling precise shunt regulation without external compensation. Its internal reference is trimmed to 1.24 V with 1.5% tolerance (TLV431C grade), and it operates down to 1.24 V cathode-anode voltage with no minimum headroom beyond VREF.

It supports both open-loop comparator mode (with integrated 1.24 V threshold) and closed-loop shunt regulation via resistive feedback between cathode and reference pins. Thermal drift is specified at ±4 mV over 0°C to 70°C, and dynamic impedance remains stable below 0.4 Ω across 0.1 mA–15 mA cathode current.

Key Specifications

Pinout & Package

TLV431CDBVTE4 is housed in a 6-pin SC-70 (DCK) package measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with exposed substrate pad connected internally to the anode terminal.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431CDBVTE4, TLV431ACDBVR offers improved accuracy in the same form factor, while TLVH431IDBVR extends voltage and current capability at the cost of package and pinout compatibility - making TLV431CDBVTE4 optimal for cost-sensitive, space-constrained 1.24–6 V regulation where ±1.5% tolerance is acceptable.

Availability

TLV431CDBVTE4 is available at Aetrix Electronics and suitable for isolated flyback SMPS design, low-voltage Zener replacement, and precision voltage monitoring requiring stable component supply across commercial temperature grades.

Supply support for TLV431CDBVTE4 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 designing analog ICs, embedded processors, and digital signal solutions for industrial, automotive, and communications markets.

The TLV431 product line delivers low-voltage, adjustable shunt references optimized for space-constrained power management in 1.8 V–3.3 V systems - targeting secondary-side regulation, voltage supervision, and comparator functions where traditional 2.5 V references cannot operate.

FAQ

What is the reference voltage tolerance of TLV431CDBVTE4 at 25°C?

The TLV431CDBVTE4 has a reference voltage tolerance of ±1.5% at 25°C, corresponding to a VREF range of 1.222 V to 1.258 V. This is the "C" grade variant within the TLV431 family, distinct from the tighter-tolerance TLV431A (±1%) and TLV431B (±0.5%) versions. The tolerance is fully characterized and tested per TI's production flow for commercial-temperature devices.

Can TLV431CDBVTE4 replace a standard Zener diode in low-voltage circuits?

Yes, TLV431CDBVTE4 is explicitly designed as a precision Zener replacement, especially below 2.5 V. With its 1.24 V reference, 0.25 Ω dynamic impedance, and sharp turn-on, it provides superior voltage stability, lower temperature drift (±4 mV over 0°C–70°C), and predictable current-sinking behavior compared to discrete Zeners - all in a 2.0 mm × 1.5 mm SC-70 package.

What is the minimum cathode current required for regulation in TLV431CDBVTE4?

The TLV431CDBVTE4 requires a minimum cathode current (IK(min)) of 55 µA to 80 µA to maintain regulation, depending on temperature and unit variation. At 25°C, typical IK(min) is 80 µA. This low requirement enables use in micropower applications such as battery-backed supervisors and low-quiescent-current power supplies where traditional TL431 (1 mA IK(min)) would be unsuitable.

Does TLV431CDBVTE4 require an output capacitor for stability?

No, TLV431CDBVTE4 is internally compensated and does not require an output capacitor between cathode and anode for basic shunt regulation stability. Its architecture remains stable with purely resistive feedback. However, if a capacitive load is added (e.g., for noise filtering), Figure 5-19 in the datasheet provides phase margin vs. capacitive load guidance to avoid oscillation - particularly relevant when driving long traces or optocoupler LEDs with parasitic capacitance.

How is the SC-70 (DCK) package of TLV431CDBVTE4 different from SOT-23-3 variants?

The TLV431CDBVTE4 uses a 6-pin SC-70 (DCK) package (2.0 mm × 1.5 mm), which is 40% smaller in footprint than the 3-pin SOT-23-3. It features dedicated CATHODE (Pin 1), REF (Pin 3), and ANODE (Pin 6) terminals plus two NC pins and a substrate tie (Pin 2). Unlike SOT-23-3, the SC-70 provides separate, non-multiplexed pins for each function - improving layout flexibility and reducing routing congestion in dense power sections.