Texas Instruments TLVH431CDBVR

Overview

TLVH431CDBVR 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 100 μA cathode current. It delivers stable voltage regulation from 1.24 V to 18 V using two external resistors and is widely used in isolated flyback SMPS feedback loops for 3.3 V systems.

For engineers reviewing the TLVH431CDBVR datasheet, TLVH431CDBVR pinout, TLVH431CDBVR application, or TLVH431CDBVR equivalent, key selection criteria include its 0.25 Ω dynamic impedance, –40°C to +125°C extended temperature range (Q-grade variant), SC-70 package footprint, and compatibility with optocoupler-based secondary-side regulation architectures.

Technical Context

The TLVH431CDBVR implements a precision bandgap reference and high-gain transconductance amplifier in a 3-terminal shunt topology. Its internal Darlington output stage enables sharp turn-on behavior and low leakage (<0.1 μA off-state cathode current), making it functionally distinct from Zener diodes while offering superior thermal stability (±12 mV VREF deviation over 0°C to 70°C).

It operates in two primary modes: open-loop comparator mode (with integrated 1.24 V reference) and closed-loop shunt regulator mode (with resistive feedback from cathode to REF). Unlike linear regulators, it requires no external compensation capacitor for stability across its full 100 μA–70 mA cathode current range.

Key Specifications

Pinout & Package

TLVH431CDBVR uses the SC-70 (DCK) package: 2.00 mm × 1.25 mm body, 6-pin configuration with substrate connection. Pin 2 is internally connected to the die substrate and 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 TLVH431CDBVR, TLVH431IDBVR trades initial accuracy for broader temperature coverage, while TLVH431BDBVR improves reference precision within the same ambient envelope-enabling optimization for either environmental ruggedness or factory-calibrated accuracy.

Availability

TLVH431CDBVR is available at Aetrix Electronics and suitable for isolated power supplies, voltage supervision circuits, and precision reference designs requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for TLVH431CDBVR 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 specializing in analog, embedded processing, and power management technologies, with decades of expertise in precision reference and power control ICs.

The TLVH431 family was designed specifically for low-voltage shunt regulation and integrated reference applications in space-constrained, efficiency-critical power systems-including isolated DC/DC converters, battery monitors, and data acquisition front-ends.

FAQ

What is the minimum cathode current required for regulation in TLVH431CDBVR?

The TLVH431CDBVR requires a minimum cathode current of 100 μA to maintain regulation, as specified in its electrical characteristics table. This value is guaranteed across the 0°C to +70°C operating range. Below this threshold, the device may exhibit reduced gain and unstable reference behavior. Designers must ensure external bias networks deliver ≥100 μA into the CATHODE pin under all operating conditions, especially during light-load or standby states. TLVH431CDBVR's low IK(min) enables efficient operation in ultra-low-power systems where traditional TL431 devices would fail to regulate.

How does TLVH431CDBVR differ from TL431 in practical circuit implementation?

TLVH431CDBVR differs from TL431 primarily in three ways: it operates down to 1.24 V (vs. 2.5 V for TL431), requires only 100 μA minimum cathode current (vs. 1 mA), and features improved line regulation (–1.5 to –2.7 mV/V). These differences allow TLVH431CDBVR to regulate lower output voltages in 3.3 V and 2.5 V systems, reduce standby power significantly, and maintain tighter reference stability under varying input conditions. TLVH431CDBVR also uses SC-70 packaging, whereas TL431 commonly appears in TO-92 or SOIC packages-making direct PCB replacement impossible without layout revision.

Can TLVH431CDBVR be used without an output capacitor?

Yes, TLVH431CDBVR is internally compensated and stable without an output capacitor between CATHODE and ANODE, unlike many linear regulators. This eliminates capacitor-related failure modes and saves board space in compact designs. However, if an output capacitor is added for filtering or transient response improvement, stability must be verified using TI's phase margin vs. capacitive load curves (Figures 5-15 to 5-17). Capacitor values exceeding 10 nF may degrade phase margin depending on cathode voltage and load current-so empirical validation is recommended for each specific application. TLVH431CDBVR's inherent stability simplifies design in cost-sensitive and size-constrained implementations.

What is the role of Pin 6 (Substrate) in TLVH431CDBVR's SC-70 package?

Pin 6 in the TLVH431CDBVR SC-70 (DCK) package is the die substrate connection, not a signal pin. Per TI's datasheet, it must be connected to the ANODE node or left electrically open-it must never be tied to CATHODE or REF. This connection influences thermal resistance (RθJC(top) = 87°C/W) and ESD robustness (±2000 V HBM). Leaving it unconnected may increase junction temperature under high-power dissipation, while incorrect routing risks latch-up or premature ESD failure. TLVH431CDBVR's substrate requirement is unique to its SC-70 implementation and differs from SOT-23 variants, so layout verification against TI's DCK mechanical drawings is essential.

Does TLVH431CDBVR support operation in comparator mode with integrated reference?

Yes, TLVH431CDBVR functions as a precision comparator with built-in 1.24 V reference when operated open-loop-i.e., without feedback from CATHODE to REF. In this mode, it compares voltage at the REF pin against its internal reference and sinks cathode current when REF exceeds 1.24 V. Its high open-loop gain ensures fast response, and its low reference input current (0.1–0.5 μA) minimizes loading on external dividers. This capability eliminates separate reference and comparator ICs in voltage-monitoring circuits. TLVH431CDBVR's comparator mode is explicitly documented in Section 7.4.1 and Figure 8-2 of its datasheet, confirming its dual-role functionality.