Texas Instruments TLVH432BQDBZTG4

Overview

TLVH432BQDBZTG4 from Texas Instruments is a B-grade (0.5% initial tolerance), 3-pin SOT-23 packaged, low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, 100 μA minimum cathode current, and –40°C to +125°C operating range. It functions as a programmable voltage reference or comparator in isolated flyback SMPS feedback loops, secondary-side regulation, and low-leakage Zener replacement applications.

For engineers reviewing the TLVH432BQDBZTG4 datasheet, TLVH432BQDBZTG4 pinout, TLVH432BQDBZTG4 application, or TLVH432BQDBZTG4 equivalent, key selection criteria include reference accuracy at temperature extremes, cathode current headroom for stable regulation, dynamic impedance under load, thermal stability in compact PCB layouts, and compatibility with optocoupler-based isolated feedback topologies.

Technical Context

The TLVH432BQDBZTG4 implements a precision bandgap reference (1.24 V) paired with a high-gain NPN-based error amplifier and Darlington sink output stage. Its internal architecture enables sharp turn-on behavior and stable closed-loop regulation down to 1.24 V with external resistor networks.

Unlike the TLVH431, the TLVH432BQDBZTG4 uses reversed pinout (REF–CATHODE–ANODE) in the SOT-23-3 package, enabling direct integration into legacy TL431-based designs where anode grounding simplifies layout. It operates without external compensation across its full 100 μA–70 mA cathode current range.

Key Specifications

Pinout & Package

SOT-23-3 package (2.92 mm × 1.30 mm body, 0.95 mm height), surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH432AQDBZTG4 and TLVH431BQDBZTG4, the TLVH432BQDBZTG4 uniquely delivers 0.5% reference accuracy in the reversed-pin SOT-23 package-enabling high-precision isolated regulation without layout revision or performance compromise.

Availability

TLVH432BQDBZTG4 is available at Aetrix Electronics and suitable for isolated SMPS feedback, low-voltage rail monitoring, and precision data converter reference applications requiring stable component supply across automotive, industrial, and telecom product lifecycles.

Supply support for TLVH432BQDBZTG4 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 ICs, with decades of expertise in precision reference and power control technologies.

The TLVH432BQDBZTG4 belongs to TI's low-voltage shunt regulator product line, engineered specifically for high-accuracy, low-power secondary-side regulation in isolated power supplies and compact voltage-monitoring systems.

FAQ

What is the reference voltage tolerance of TLVH432BQDBZTG4 at 25°C?

The TLVH432BQDBZTG4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal V_REF with a range of 1.234 V to 1.246 V. This B-grade specification is confirmed in Section 5.7 of the official TI datasheet SLVS555N and applies exclusively to the TLVH432B variant in SOT-23-3 packaging. The TLVH432BQDBZTG4 maintains this tolerance across its full –40°C to +125°C operating range with ≤±11 mV deviation.

How does the pinout of TLVH432BQDBZTG4 differ from TLVH431BQDBZTG4?

The TLVH432BQDBZTG4 uses a reversed SOT-23-3 pinout: Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE. In contrast, TLVH431BQDBZTG4 uses the standard order: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. This difference is explicitly documented in Figures 4-4 and 4-5 of the TI datasheet and enables TLVH432BQDBZTG4 to match TL431 footprints when the anode is grounded. Both share identical electrical specs and package dimensions.

What is the minimum cathode current required for regulation in TLVH432BQDBZTG4?

The TLVH432BQDBZTG4 requires a minimum cathode current (I_K(min)) of 100 μA to maintain regulation, as specified in Sections 5.5–5.7 of the TI datasheet. This value holds across the full –40°C to +125°C temperature range. Below this threshold, gain drops significantly, causing poor regulation and delayed response. Designers must ensure external bias networks deliver ≥100 μA under worst-case conditions, including lowest input voltage and highest temperature.

Can TLVH432BQDBZTG4 operate without an output capacitor?

Yes, TLVH432BQDBZTG4 is internally compensated and stable without an output capacitor between cathode and anode, per Section 7.3 of the TI datasheet. This eliminates mandatory external capacitance, reducing BOM count and PCB area. However, if a capacitor is added for noise filtering or transient response, Figures 5-15 to 5-17 provide phase-margin guidance versus capacitive load-stability is maintained up to ~10 nF at V_KA = 1.25 V.

What are the absolute maximum ratings for cathode voltage and current in TLVH432BQDBZTG4?

The absolute maximum cathode voltage (V_KA) for TLVH432BQDBZTG4 is 20 V, and the absolute maximum cathode current (I_K) is 80 mA, as defined in Section 5.1 of the TI datasheet. Exceeding these limits risks permanent damage. For continuous operation, the recommended cathode voltage is 1.24 V to 18 V and cathode current is 0.1 mA to 70 mA. Thermal derating is required above 70°C ambient due to R_θJA = 206°C/W for the SOT-23-3 package.