Texas Instruments TLVH431BILPR

Overview

TLVH431BILPR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% initial reference voltage tolerance at 25°C, 1.24 V nominal reference voltage, and operation down to 1.24 V cathode-to-anode voltage. It delivers stable regulation across –40°C to +125°C, supports cathode currents from 100 μA to 70 mA, and features 0.25 Ω typical dynamic impedance - enabling use as a Zener replacement or error amplifier in isolated flyback SMPS feedback loops.

For engineers reviewing the TLVH431BILPR datasheet, TLVH431BILPR pinout, TLVH431BILPR application, or TLVH431BILPR equivalent, key selection considerations include its B-grade accuracy, TO-92 package thermal resistance (140°C/W), ultra-low reference current (≤0.5 μA), and compatibility with optocoupler-based secondary-side regulation in 3.3 V systems.

Technical Context

The TLVH431BILPR implements an internal bandgap reference and high-gain NPN-based error amplifier driving a Darlington output stage. Its open-loop comparator mode enables precise voltage monitoring without external references, while closed-loop operation with resistive feedback between cathode and reference pins achieves adjustable output regulation from 1.24 V to 18 V.

It is internally compensated for stability without an output capacitor, though phase margin vs. capacitive load data (Figures 5-15–5-17) supports design of compensation networks up to 10 nF. The device's substrate-connected pin (Pin 2 in SC-70/SOT-23 variants) must be tied to anode or left floating - a constraint confirmed for the LP (TO-92) package variant used by TLVH431BILPR.

Key Specifications

Pinout & Package

TLVH431BILPR uses the TO-92 (LP) package: 4.30 mm × 4.30 mm body, axial leaded, through-hole mount. Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF - no NC or substrate pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AILPR and TLVH431CLPR, TLVH431BILPR provides the highest initial reference accuracy (±0.5%) in the same TO-92 footprint - critical for uncalibrated systems requiring guaranteed performance across temperature without post-manufacture trimming.

Availability

TLVH431BILPR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and precision sensor signal chains requiring stable component supply and long-term lifecycle support.

Supply support for TLVH431BILPR 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 for industrial, automotive, and communications markets.

The TLVH431 family was designed as a low-voltage, high-accuracy upgrade to the TL431, targeting secondary-side regulation in compact 3.3 V and lower isolated power supplies and precision voltage monitoring in harsh-temperature environments.

FAQ

What is the reference voltage tolerance of TLVH431BILPR at 25°C?

TLVH431BILPR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal V_REF with min/max values of 1.234 V and 1.246 V. This B-grade accuracy is specified in Section 5.7 of the TI datasheet SLVS555N and applies across all temperature grades (C/I/Q) of the TLVH431B variant.

Which package does TLVH431BILPR use, and what are its mechanical dimensions?

TLVH431BILPR uses the TO-92 (LP) package: a 3-pin axial-leaded through-hole package with nominal body dimensions of 4.30 mm × 4.30 mm. Pin 1 is CATHODE, Pin 2 is ANODE, and Pin 3 is REF - confirmed in Figure 4-3 and Table 11-1 of the TI datasheet SLVS555N.

Can TLVH431BILPR operate with cathode currents below 100 µA?

No - TLVH431BILPR requires ≥100 µA cathode current (I_K(min)) to maintain regulation, as specified in Sections 5.5–5.7 of the datasheet. Operation below this threshold results in insufficient gain and unstable reference behavior; the device may not sink current reliably or hold V_REF within tolerance.

How does TLVH431BILPR differ from TLVH432BILPR?

TLVH431BILPR and TLVH432BILPR share identical electrical specifications but differ in pinout: TLVH431BILPR (TO-92) uses Pin 1=CATHODE, Pin 2=ANODE, Pin 3=REF, whereas TLVH432 variants reverse ANODE and REF. TLVH432BILPR does not exist - TLVH432 is only offered in SOT-23 and SOT-89 packages per TI's orderable addendum.

Is an output capacitor required for stability with TLVH431BILPR?

No - TLVH431BILPR is internally compensated and stable without an output capacitor between cathode and anode. However, if a capacitor is added for noise filtering or transient response shaping, Figures 5-15–5-17 in the datasheet provide phase margin vs. capacitive load data to guide selection up to 10 nF.