Texas Instruments TLV431BCDBVRE4

Overview

TLV431BCDBVRE4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, 0.5% initial tolerance at 25°C, and operation down to 1.24 V cathode-anode voltage. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical minimum cathode current, and supports output voltage adjustment from 1.24 V to 6 V using two external resistors - ideal for secondary-side regulation in isolated 3.3 V flyback SMPSs.

For engineers reviewing the TLV431BCDBVRE4 datasheet, TLV431BCDBVRE4 pinout, TLV431BCDBVRE4 application, or TLV431BCDBVRE4 equivalent, key selection criteria include reference accuracy over temperature (±4 mV from 0°C to 70°C), ultra-low cathode current requirement, SC-70 package footprint, and compatibility with optocoupler-based feedback loops in space-constrained power supplies.

Technical Context

The TLV431BCDBVRE4 implements a precision bandgap reference and high-gain NPN-based error amplifier in a single 3-terminal shunt topology. Its internal architecture enables closed-loop regulation via resistive feedback from cathode to reference pin, or open-loop comparator operation with integrated 1.24 V threshold.

It operates with ≥1.24 V cathode-to-anode voltage headroom and requires ≥55 µA cathode current to maintain regulation across its full temperature range (0°C to 70°C for 'C' grade). The device is internally compensated and stable without an output capacitor, supporting direct integration into compact isolated feedback networks.

Key Specifications

Pinout & Package

TLV431BCDBVRE4 is housed in a 6-pin SC-70 (DCK) package measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with thermal resistance R_θJA = 87°C/W. Pin 1 is CATHODE, Pin 3 is REFERENCE, and 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 TLV431BCDBVRE4, TLV431ACDBVR trades 0.5% accuracy for cost savings while maintaining identical form factor and thermal performance, whereas TLVH431IDBVR expands operating range but requires PCB redesign due to SOT-23-3 pinout and larger footprint.

Availability

TLV431BCDBVRE4 is available at Aetrix Electronics and suitable for isolated flyback SMPSs, voltage monitoring circuits, and Zener-replacement designs requiring stable component supply, tight reference accuracy, and ultra-compact packaging.

Supply support for TLV431BCDBVRE4 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 precision analog ICs and power management solutions.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained power supplies and sensing applications - targeting 3.3 V and lower systems where legacy TL431 devices cannot operate.

FAQ

What is the reference voltage tolerance of TLV431BCDBVRE4 at 25°C?

The TLV431BCDBVRE4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal reference with a range of 1.234 V to 1.246 V. This tight tolerance is specified for the 'B' grade variant and is confirmed in Section 5.7 of the TI datasheet SLVS139Z. TLV431BCDBVRE4 maintains this accuracy across its commercial temperature range (0°C to 70°C).

Which package type does TLV431BCDBVRE4 use, and what are its dimensions?

TLV431BCDBVRE4 uses the SC-70 (DCK) package, a 6-pin surface-mount outline measuring 2.0 mm × 1.5 mm. This package is documented in TI's Package Information table and provides a 40% smaller footprint than SOT-23-3. Thermal resistance is R_θJA = 87°C/W, making it suitable for thermally constrained layouts in compact power modules.

Can TLV431BCDBVRE4 replace a standard Zener diode in a circuit?

Yes, TLV431BCDBVRE4 can directly replace low-voltage Zener diodes (1.24 V to 6 V) with significant improvements: 0.25 Ω dynamic impedance vs typical Zener impedance >10 Ω, ±4 mV temperature drift (0°C–70°C) vs >10 mV for Zeners, and sharp turn-on characteristics. Its active regulation eliminates Zener's poor low-current performance and voltage drift - confirmed in TI's Description and Applications sections.

What is the minimum cathode current required for regulation in TLV431BCDBVRE4?

The TLV431BCDBVRE4 requires a minimum cathode current of 55 µA to maintain regulation at 25°C, rising to 80 µA maximum over its full 0°C to 70°C operating range. This value is specified in Section 5.7 (Electrical Characteristics for TLV431B) and enables ultra-low-power operation in standby or battery-powered systems where TL431 (1 mA min) would be unsuitable.

How does TLV431BCDBVRE4 function in an isolated flyback power supply?

In an isolated flyback supply, TLV431BCDBVRE4 serves as both voltage reference and error amplifier on the secondary side. It compares a scaled version of the output voltage (via resistor divider) to its 1.24 V internal reference, then sinks current into the optocoupler LED to adjust primary-side duty cycle. TI validates this use case in Figure 8-1 and Section 8.1, confirming stable 3.3 V regulation with <±1% total error.