Texas Instruments TLV431BCDBVTG4

Overview

TLV431BCDBVTG4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% reference voltage tolerance at 25°C, 1.24V nominal VREF, and operation down to 1.24V cathode-anode voltage. It delivers 0.25Ω typical dynamic impedance, 80µA typical minimum cathode current, and supports output voltage adjustment from 1.24V to 6V using two external resistors - ideal for secondary-side regulation in compact 3.3V isolated flyback SMPSs.

For engineers reviewing the TLV431BCDBVTG4 datasheet, TLV431BCDBVTG4 pinout, TLV431BCDBVTG4 application, or TLV431BCDBVTG4 equivalent, key selection criteria include its SC-70 (DCK) package footprint, tight 0.5% initial VREF tolerance, ultra-low IK(min) of 55–100µA across temperature, stability without output capacitance, and use as Zener replacement or comparator with integrated reference in space-constrained power and monitoring circuits.

Technical Context

The TLV431BCDBVTG4 implements a bandgap-referenced error amplifier driving a Darlington sink output stage, enabling precise shunt regulation or open-loop comparator operation. Its internal architecture supports both closed-loop feedback (e.g., optocoupler-coupled flyback regulation) and open-loop threshold detection without external reference components.

It operates with ≥1.24V cathode-to-anode headroom and requires ≥0.1mA cathode current for regulation; reference pin bias current is ≤0.5µA typical. Thermal drift is specified at 4mV (0°C to 70°C), 6mV (–40°C to 85°C), and 11mV (–40°C to 125°C), matching the TLV431B grade's industrial temperature range (–40°C to 85°C).

Key Specifications

Pinout & Package

TLV431BCDBVTG4 is housed in an ultra-small SC-70 (DCK) 6-pin package with 0.65 mm pitch. Pin 1 is CATHODE, Pin 3 is ANODE, and Pin 3 (ANODE) serves as the common ground reference node. The substrate connection (Pin 2) must be tied 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 TLV431BCDBVTG4, TLV431ACDBVT trades 0.5% precision for lower unit cost while maintaining identical form/fit/function; TLVH431IDBVR offers broader voltage/current capability but requires PCB redesign due to SOT-23-3 pinout and larger footprint.

Availability

TLV431BCDBVTG4 is available at Aetrix Electronics and suitable for isolated flyback power supplies, precision voltage monitoring circuits, and Zener-replacement applications requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for TLV431BCDBVTG4 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 leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, efficiency, and design enablement.

The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained power management and feedback control systems - targeting industrial, computing, and telecom applications demanding precision below 2.5V.

FAQ

What is the operating temperature range for TLV431BCDBVTG4?

The TLV431BCDBVTG4 is rated for industrial operation from –40°C to +85°C. This range is confirmed in Section 5.3 (Recommended Operating Conditions) and Table 5.7 (Electrical Characteristics for TLV431B), where parameters like VREF(dev) and IK(min) are explicitly specified across this interval. Its "BI" suffix denotes the industrial-grade temperature qualification.

Does TLV431BCDBVTG4 require an output capacitor for stability?

No, TLV431BCDBVTG4 is internally compensated and remains stable without an output capacitor between cathode and anode - a key advantage over many linear regulators. Section 7.3 confirms this: "Unlike many linear regulators, TLV431 is internally compensated to be stable without an output capacitor." Capacitors may be added for noise filtering but are not required for loop stability.

How is the output voltage set on TLV431BCDBVTG4?

Output voltage is set using two external resistors forming a divider from cathode to anode, with the REF pin connected to the divider midpoint. Per Figure 6-2 and Section 7.1, VO = VREF × (1 + R1/R2) + Iref × R1. With Iref ≤ 0.5µA, the second term is negligible for R1 ≤ 1 MΩ, making VO ≈ 1.24V × (1 + R1/R2) - enabling precise adjustment from 1.24V to 6V.

What is the minimum cathode current needed for regulation in TLV431BCDBVTG4?

The minimum cathode current (IK(min)) for TLV431BCDBVTG4 is 55 µA minimum and 100 µA maximum across –40°C to +85°C, as specified in Table 5.7. This value ensures the internal amplifier remains in linear region; operation below 55 µA risks loss of regulation and degraded transient response.

Can TLV431BCDBVTG4 be used as a comparator?

Yes, TLV431BCDBVTG4 functions as a comparator with integrated 1.24V reference in open-loop mode (Section 7.4.1). When cathode current ≥100 µA is supplied and REF is driven externally, it provides sharp turn-on and rail-to-rail output swing - used for voltage monitoring, brownout detection, and threshold triggering without external reference components.