TL431IZT

Product Overview

• Category: Integrated Circuit (IC)
• Use: Voltage reference and shunt regulator
• Characteristics: Adjustable precision, low voltage reference, programmable output voltage, high accuracy, low quiescent current
• Package: TO-92, SOT-23, SOIC-8, DIP-8
• Essence: Precision adjustable shunt regulator
• Packaging/Quantity: Tape and reel packaging, 2500 units per reel

Specifications

• Reference Voltage Range: 2.495V to 36V
• Output Voltage Range: Vref to 36V
• Operating Temperature Range: -40°C to +85°C
• Quiescent Current: 1.0mA (max)
• Dynamic Output Impedance: 0.22Ω (typ)
• Cathode Current Range: 1.0mA to 100mA

Pin Configuration

The TL431IZT has three pins:

1. Anode (A): Connected to the positive terminal of the power supply.
2. Cathode (K): Connected to the load or ground.
3. Reference (R): Connected to an external resistor divider network to set the desired output voltage.

Functional Features

• Voltage Reference: The TL431IZT provides a stable and precise voltage reference that can be adjusted using an external resistor divider network.
• Shunt Regulator: It acts as a shunt regulator by maintaining a constant voltage drop between the anode and cathode terminals.
• Programmable Output Voltage: The output voltage can be easily programmed by selecting appropriate resistor values in the external resistor divider network.
• High Accuracy: The TL431IZT offers high accuracy with a low temperature coefficient, ensuring reliable voltage regulation.
• Low Quiescent Current: It has a low quiescent current, making it suitable for low-power applications.

Advantages and Disadvantages

Advantages

• Precise voltage regulation
• Adjustable output voltage
• Wide operating temperature range
• Low quiescent current consumption
• Easy to use and integrate into circuits

Disadvantages

• Requires an external resistor divider network for voltage adjustment
• Limited maximum cathode current capability (100mA)

Working Principles

The TL431IZT operates based on the principle of a shunt regulator. It compares the reference voltage at the reference pin with the voltage across the resistor divider network connected to the cathode pin. By adjusting the resistance values in the divider network, the desired output voltage can be set. The TL431IZT then regulates the voltage by varying its internal impedance to maintain a constant voltage drop between the anode and cathode terminals.

Detailed Application Field Plans

The TL431IZT finds extensive application in various fields, including:

1. Power Supplies: It is commonly used in linear power supplies to provide stable and accurate voltage references.
2. Battery Charging Systems: The TL431IZT is utilized in battery charging circuits to regulate the charging voltage and ensure proper charging levels.
3. Voltage Regulators: It can be employed as a voltage regulator in electronic devices to maintain a constant voltage level for sensitive components.
4. Audio Amplifiers: The TL431IZT is used in audio amplifiers to provide precise biasing and voltage stabilization.
5. LED Drivers: It finds application in LED driver circuits to regulate the forward voltage and current for efficient LED operation.

Detailed and Complete Alternative Models

Some alternative models to the TL431IZT include:

1. LM4040: Precision Micropower Shunt Voltage Reference
2. LT1236: Precision Reference
3. MAX6126: Ultra-High-Precision Voltage Reference
4. REF02: Precision Voltage Reference
5. ADR431: Precision Shunt Voltage Reference

These alternative models offer similar functionality and characteristics, providing options for different design requirements.

In conclusion, the TL431IZT is a versatile voltage reference and shunt regulator IC with adjustable precision and low quiescent current. It finds application in various fields such as power supplies, battery charging systems, voltage regulators, audio amplifiers, and LED drivers. While it requires an external resistor divider network for voltage adjustment, its advantages include precise voltage regulation, programmable output voltage, and high accuracy. Alternative models like LM4040, LT1236, MAX6126, REF02, and ADR431 offer similar functionality as alternatives to the TL431IZT.