Texas Instruments TLVH432BCPKG3

Overview

TLVH432BCPKG3 from Texas Instruments is a B-grade (0.5% initial tolerance), low-voltage adjustable precision shunt regulator in SOT-89-3 package, delivering 1.24 V reference voltage with 0.25 Ω typical dynamic impedance and operating across –40°C to +125°C. It functions as an error amplifier or comparator with integrated reference in isolated flyback SMPS feedback loops, secondary-side voltage regulation, and low-leakage Zener replacement circuits.

For engineers reviewing the TLVH432BCPKG3 datasheet, TLVH432BCPKG3 pinout, TLVH432BCPKG3 application, or TLVH432BCPKG3 equivalent, key selection criteria include its 100 μA minimum cathode current requirement, 1.24 V reference accuracy at 25°C, SOT-89 pin configuration (CATHODE–REF–ANODE), and compatibility with optocoupler-based isolated regulation for 3.3 V output supplies.

Technical Context

The TLVH432BCPKG3 implements a precision bandgap reference and high-gain transconductance amplifier in a 3-terminal shunt topology. Its internal architecture forces the REF pin to 1.24 V when cathode current exceeds 100 μA, enabling closed-loop regulation via external resistor dividers or open-loop comparator operation with sharp turn-on characteristics.

Unlike the TLVH431, the TLVH432 variant uses reversed pinout in SOT-89 (Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE) to simplify PCB layout in space-constrained power supply feedback paths. It maintains identical electrical specs-including 1.24 V reference, 0.25 Ω dynamic impedance, and –40°C to +125°C operation-across both packages.

Key Specifications

Pinout & Package

SOT-89-3 package (4.50 mm × 2.50 mm body size) with gull-wing leads; thermally enhanced for power dissipation in compact regulators.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH432BIDBZR and TLVH431BQDBVR, TLVH432BCPKG3 provides superior thermal performance (R_θJA = 52°C/W) and simplified 3-pin routing for high-reliability isolated SMPS feedback, making it optimal for automotive and industrial power supplies where thermal margin and layout simplicity are critical.

Availability

TLVH432BCPKG3 is available at Aetrix Electronics and suitable for isolated flyback SMPS design, precision voltage monitoring, and low-leakage Zener replacement applications requiring stable component supply and full-temperature-grade assurance.

Supply support for TLVH432BCPKG3 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 IC design.

The TLVH432 belongs to TI's precision shunt regulator product line, engineered specifically for high-accuracy, low-voltage secondary-side regulation in isolated DC/DC converters and compact voltage supervision systems.

FAQ

What is the reference voltage tolerance of TLVH432BCPKG3 at 25°C?

The TLVH432BCPKG3 has a B-grade reference voltage tolerance of ±0.5% at 25°C, meaning its V_REF is guaranteed between 1.234 V and 1.246 V under nominal conditions. This tight tolerance is confirmed in Section 5.7 of the official datasheet and applies specifically to the TLVH432B variant in SOT-89 packaging. The TLVH432BCPKG3 maintains this specification across its full operating temperature range.

How does the pinout of TLVH432BCPKG3 differ from TLVH431 variants?

The TLVH432BCPKG3 uses a CATHODE–REF–ANODE pinout (Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE) in its SOT-89 package, whereas TLVH431 variants use REF–CATHODE–ANODE in SOT-23-3 or REF–CATHODE–ANODE–NC–NC in SOT-23-5. This reversal simplifies feedback loop routing in flyback designs where cathode connects directly to optocoupler anode. The TLVH432BCPKG3 pinout is explicitly defined in Figure 4-7 of the datasheet.

What is the minimum cathode current required for regulation in TLVH432BCPKG3?

The TLVH432BCPKG3 requires a minimum cathode current (I_K(min)) of 100 μA to enter and maintain regulation, as specified in Sections 5.5–5.7 of the datasheet. Below this threshold, gain drops significantly and reference accuracy degrades. This value is identical across all TLVH432 grades and is validated over the full –40°C to +125°C temperature range.

Can TLVH432BCPKG3 operate without an output capacitor?

Yes, TLVH432BCPKG3 is internally compensated and stable without an output capacitor between CATHODE and ANODE, unlike many linear regulators. Its 0.25 Ω dynamic impedance and inherent phase margin allow direct connection to optocouplers or resistive loads. However, if a capacitor is added for filtering, Figures 5-15 to 5-17 in the datasheet provide stability guidance based on capacitive load and cathode voltage.

What is the maximum cathode voltage rating for TLVH432BCPKG3?

The absolute maximum cathode voltage (V_KA) for TLVH432BCPKG3 is 20 V, as stated in Section 5.1 (Absolute Maximum Ratings). Its recommended operating range extends from V_REF (1.24 V) up to 18 V, enabling adjustable output regulation across a wide span while maintaining specified accuracy and thermal performance within the SOT-89 package limits.