Texas Instruments TLV431AIDBZRG4

Overview

TLV431AIDBZRG4 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.

For engineers reviewing the TLV431AIDBZRG4 datasheet, TLV431AIDBZRG4 pinout, TLV431AIDBZRG4 application, or TLV431AIDBZRG4 equivalent, key selection criteria include reference accuracy over temperature (±11 mV from –40°C to 125°C), ultra-small SC-70 package footprint, open-loop comparator capability with integrated reference, and compatibility with optocoupler-based feedback loops in 3.3 V systems.

Technical Context

The TLV431AIDBZRG4 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 operation (comparator with built-in 1.24 V reference).

It operates with cathode-to-anode voltage (VKA) from 1.24 V to 6 V and requires ≥55 µA cathode current for regulation across commercial/industrial temperature ranges. The device is internally compensated and stable without external output capacitance, though phase margin vs. capacitive load is characterized up to 1 nF.

Key Specifications

Pinout & Package

TLV431AIDBZRG4 is housed in a 3-pin SC-70 (DCK) package measuring 2.0 mm × 1.5 mm - 40% smaller than SOT-23-3 - with gull-wing leads optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431ACDBZR, TLV431AIDBZRG4 trades 0.5% accuracy for guaranteed operation from –40°C to 85°C; compared with TLVH431IDBVR, it offers smaller size and lower cost for ≤6 V, ≤15 mA applications but lacks extended voltage/current capability.

Availability

TLV431AIDBZRG4 is available at Aetrix Electronics and suitable for isolated flyback power supplies, precision voltage monitoring circuits, and low-voltage shunt regulation applications requiring stable component supply and long-term manufacturability.

Supply support for TLV431AIDBZRG4 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, power management, and signal chain solutions.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation and integrated comparator functions in space- and power-constrained systems such as isolated DC/DC converters and portable instrumentation.

FAQ

What is the maximum cathode voltage supported by TLV431AIDBZRG4?

The TLV431AIDBZRG4 supports a maximum cathode-to-anode voltage (VKA) of 7 V, as specified in its Absolute Maximum Ratings. This allows safe operation in circuits where the cathode node may swing up to 7 V above the anode (typically ground), including transient conditions in flyback feedback networks and overvoltage protection schemes. Operation beyond this limit risks permanent damage.

Does TLV431AIDBZRG4 require an external output capacitor for stability?

No, TLV431AIDBZRG4 is internally compensated and remains stable without an external output capacitor between cathode and anode. This simplifies design in shunt regulator configurations. However, if a capacitor is added for noise filtering or loop compensation, phase margin data (Figure 5-19 through 5-21) must be consulted to avoid oscillation - stability depends on capacitive load value and operating VKA.

Can TLV431AIDBZRG4 be used as a standalone comparator without external components?

Yes, TLV431AIDBZRG4 can operate as an open-loop comparator with integrated 1.24 V reference. Connect the signal to be monitored at the REF pin, pull CATHODE up to a logic supply via a current-limiting resistor, and tie ANODE to ground. When REF voltage exceeds 1.24 V ±1%, the device sinks current - producing a logic-low output. No external reference is needed, but ≥55 µA cathode current must be supplied for reliable switching.

What is the purpose of the substrate connection (Pin 2) in TLV431AIDBZRG4's SC-70 package?

In the TLV431AIDBZRG4 SC-70 (DCK) package, Pin 2 is the substrate connection and must be either tied directly to the ANODE pin or left electrically floating. It is not a signal pin and has no internal circuit connection. Leaving it unconnected or improperly biased may cause parametric shifts or instability; TI explicitly states it must be connected to ANODE or left open - never driven to a different potential.

How does TLV431AIDBZRG4 differ from TL431 in low-voltage applications?

TLV431AIDBZRG4 differs from TL431 primarily in its 1.24 V reference voltage (vs. TL431's 2.5 V), enabling regulation in sub-2.5 V systems like 1.8 V or 2.5 V rails. It also features lower minimum cathode current (55 µA vs. 1 mA), making it suitable for ultra-low-power designs. The TLV431AIDBZRG4's SC-70 package is significantly smaller than TL431's TO-92 or SOIC-8 options, and its temperature drift is characterized down to –40°C, whereas standard TL431 variants often lack extended-range specs.