STMicroelectronics TL1431IYDT

Overview

TL1431IYDT from STMicroelectronics is an automotive-grade adjustable shunt voltage reference IC with 0.4% initial voltage precision, guaranteed operation from –40 °C to +125 °C, and sink current capability from 1 mA to 100 mA. It delivers a stable 2.5 V reference input voltage (V_REF) and supports programmable output voltages from 2.5 V to 36 V using two external resistors-commonly deployed in isolated flyback feedback loops and precision voltage monitoring circuits.

For engineers reviewing the TL1431IYDT datasheet, TL1431IYDT pinout, TL1431IYDT application, or TL1431IYDT equivalent, this device is selected for automotive power supply supervision, industrial DC-DC converter regulation, and high-reliability analog feedback networks where temperature-stable reference performance and AEC-Q100-aligned qualification are required.

Technical Context

The TL1431IYDT functions as a 3-terminal adjustable shunt regulator with internal bandgap reference, error amplifier, and output transistor. Its architecture enables precise cathode-to-anode voltage control via external resistor divider feedback to the REF pin, with dynamic impedance as low as 0.2 Ω at 1–100 mA cathode current.

It operates across a wide cathode current range (1–100 mA) and maintains reference stability under varying load and temperature conditions-verified over –40 °C to +125 °C with ≤30 mV total V_REF deviation and ±100 ppm/°C max temperature coefficient.

Key Specifications

Pinout & Package

TL1431IYDT is supplied in SO-8 (batwing plastic micropackage), a surface-mount package with 8 leads and enhanced thermal dissipation (R_thJA = 85 °C/W). Pin 1 is Cathode, Pin 2 is Anode, Pin 3 is REF, Pins 4–8 are NC (no connect) per Figure 2 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431BIDR and LM4040CIM3X-ADJ, TL1431IYDT offers superior voltage precision (0.4% vs. 0.5%), lower dynamic impedance (0.2 Ω vs. ≥0.3 Ω), and full 2.5–36 V adjustability-making it uniquely suitable for automotive and industrial isolated power designs requiring both accuracy and flexibility.

Availability

TL1431IYDT is available at Aetrix Electronics and suitable for automotive power management, industrial DC-DC converters, and high-reliability battery monitoring systems requiring stable component supply with AEC-Q100 alignment and long-term manufacturability.

Supply support for TL1431IYDT 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog components for automotive, industrial, and consumer markets.

The TL1431 product line delivers precision programmable shunt references optimized for feedback regulation in isolated switch-mode power supplies and voltage supervision circuits-designed specifically for robustness in harsh thermal and electrical environments.

FAQ

What is the minimum cathode current required for regulation in TL1431IYDT?

The TL1431IYDT requires a minimum cathode current (I_min) of 0.5 mA to maintain regulation, verified across –40 °C to +125 °C. This value is specified in Table 6 of the datasheet and ensures stable reference behavior even at light loads typical in standby or fault-monitoring modes.

Can TL1431IYDT replace TL431 in existing designs?

Yes-TL1431IYDT is pin-compatible with TL431 in SO-8 packages and shares identical pinout (Cathode, Anode, REF). However, its tighter 0.4% initial precision, lower dynamic impedance (0.2 Ω), and AEC-Q100 qualification make it a functional upgrade-not just a drop-in replacement-for automotive and high-reliability applications.

Does TL1431IYDT require external compensation for stability?

No external compensation is needed for standard configurations. The device is internally compensated and remains stable with capacitive loads up to 10 nF, as confirmed in Figure 20 of the datasheet. For >10 nF loads or high-frequency feedback loops, a small series resistor (10–100 Ω) at the REF pin may be added to ensure phase margin.

What is the maximum power dissipation of TL1431IYDT in SO-8 package?

In SO-8 (batwing) package, TL1431IYDT has a maximum power dissipation of 960 mW at T_amb = 25 °C, calculated using R_thJA = 85 °C/W and T_j(max) = 150 °C. Derating is required above 25 °C ambient-e.g., ~700 mW at 50 °C ambient per linear derating curve in Table 3.