Texas Instruments TLVH432AIPKG3

Overview

TLVH432AIPKG3 from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-89-3 package, providing 1.24 V reference voltage with ±1% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation from 1.24 V to 18 V output range. It serves as an error amplifier or voltage reference in isolated flyback SMPS feedback loops and low-voltage Zener replacement circuits.

For engineers reviewing the TLVH432AIPKG3 datasheet, TLVH432AIPKG3 pinout, TLVH432AIPKG3 application, or TLVH432AIPKG3 equivalent, key selection criteria include cathode current range (100 μA–70 mA), thermal stability over –40°C to +125°C, reference voltage deviation (≤31 mV over full temperature range for Q-grade), and SOT-89 pin compatibility with TLVH432-series variants.

Technical Context

The TLVH432AIPKG3 implements a 3-terminal adjustable shunt reference architecture with internal 1.24 V bandgap reference and high-gain NPN-based error amplifier. Its functional block includes a precision reference input (REF), current-sinking output (CATHODE), and common return path (ANODE), enabling closed-loop regulation via external resistor dividers or open-loop comparator operation.

Unlike the TLVH431, the TLVH432AIPKG3 uses reversed pinout in SOT-89: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE - confirmed in Figure 4-7 and Pin Functions table. This configuration supports direct integration into optocoupler-coupled secondary-side regulation where cathode connects to opto-LED anode and REF senses output voltage divider.

Key Specifications

Pinout & Package

SOT-89-3 package: 4.50 mm × 2.50 mm body, 1.0 mm max height, gull-wing leads, tape-and-reel packaging. Thermal resistance R_θJA = 52°C/W enables >1 W dissipation at TA = 25°C with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH432AIPKG3, TLVH432AIDBZR offers 40% smaller footprint but lower thermal performance (R_θJA = 206°C/W), while TLVH431AIPK retains identical thermal capability but demands schematic and layout changes due to inverted pin mapping - making TLVH432AIPKG3 optimal for new designs prioritizing thermal robustness and simplified optocoupler interface.

Availability

TLVH432AIPKG3 is available at Aetrix Electronics and suitable for isolated flyback SMPS feedback, low-voltage Zener replacement, and power-rail voltage monitoring requiring stable component supply across automotive, industrial, and telecom applications.

Supply support for TLVH432AIPKG3 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and high-reliability components.

The TLVH432AIPKG3 belongs to TI's precision shunt reference product line, designed specifically for secondary-side regulation in isolated DC-DC converters and low-voltage reference applications demanding high accuracy and wide temperature operation.

FAQ

What is the exact pinout configuration of TLVH432AIPKG3 in the SOT-89 package?

The TLVH432AIPKG3 uses a reversed SOT-89 pinout: Pin 1 is CATHODE, Pin 2 is REF, and Pin 3 is ANODE - confirmed in Figure 4-7 of the official datasheet. This differs from TLVH431 variants and aligns with TI's TLVH432 family specification to simplify optocoupler connection in flyback feedback paths. Always verify orientation using the package notch and TI's mechanical drawing SLVS555N.

Does TLVH432AIPKG3 require an output capacitor for stability?

No, TLVH432AIPKG3 is internally compensated and operates stably without an output capacitor between CATHODE and ANODE in most applications. However, if capacitive loading is introduced (e.g., long traces or optocoupler CTR variation), Figures 5-15 through 5-17 in the datasheet provide phase-margin guidance for selecting ≤10 nF ceramic capacitors to maintain stability across operating conditions.

What is the minimum cathode current required for regulation in TLVH432AIPKG3?

The TLVH432AIPKG3 requires a minimum cathode current of 100 μA to maintain regulation, as specified in Section 5.5 of the datasheet. Below this level, gain drops significantly, causing poor reference tracking and increased output voltage error - especially critical in low-power UVLO or battery-monitoring circuits where IK may approach 60 μA at temperature extremes.

How does the reference voltage tolerance of TLVH432AIPKG3 compare across temperature?

TLVH432AIPKG3 (A-grade) exhibits ≤31 mV V_REF deviation over –40°C to +125°C, corresponding to ±0.025% average TC over that range. This is tighter than standard-grade TLVH432 (±1.5%) and sufficient for industrial power supplies where output accuracy must remain within ±2% over full temperature swing without calibration.

Can TLVH432AIPKG3 replace TL431 in existing designs?

TLVH432AIPKG3 can replace TL431 only with circuit modifications: it operates down to 1.24 V (vs. TL431's 2.5 V), has lower I_K(min) (100 μA vs. 1 mA), and uses different pinouts. Direct substitution is not possible without adjusting feedback resistors, verifying headroom, and confirming SOT-89 mechanical fit. For drop-in replacement, consider TLVH431AIPK with matching pinout but higher V_REF.