The UA431AWC is a precision adjustable shunt regulator manufactured by Texas Instruments (formerly National Semiconductor). It is designed for use in a wide range of applications requiring a stable and adjustable voltage reference.

Applications

• Precision Voltage Reference: Used as a precise voltage reference in various electronic circuits.
• Adjustable Power Supplies: Employed in adjustable power supplies to maintain a stable output voltage.
• Error Amplifiers: Integrated into error amplifier circuits for feedback control systems.
• Linear Regulators: Used as a shunt regulator in linear regulator designs.
• Switching Power Supplies: Used in switching power supplies to provide precise voltage regulation.
• Voltage Monitoring: Employed in voltage monitoring circuits to detect over- or under-voltage conditions.

Features

• Programmable Output Voltage: The output voltage can be set to any value between Vref (2.5V typical) and 36V with two external resistors.
• Low Dynamic Output Impedance: Provides a stable output voltage with minimal variation under changing load conditions.
• Sink Current Capability: Supports a wide range of sink currents from 1mA to 100mA.
• Low Output Noise: Minimal output noise ensures clean and stable voltage regulation.
• Tight Tolerance: Offers a tight tolerance on the reference voltage (Vref), ensuring accuracy.
• Wide Operating Temperature Range: Operates reliably over a wide temperature range.

Benefits

• High Precision: Provides a highly accurate and stable voltage reference.
• Flexibility: Adjustable output voltage allows for customization to specific application requirements.
• Stable Performance: Low dynamic output impedance ensures stable voltage regulation under varying load conditions.
• Wide Application Range: Suitable for a broad range of applications requiring voltage regulation and reference.
• Cost-Effective: Offers a cost-effective solution for precision voltage regulation.

Additional Details

The UA431AWC is typically available in through-hole and surface-mount packages. The device operates by sinking current to regulate the voltage at the REF pin to the internal reference voltage. External resistors are used to divide down the output voltage and feed it back to the REF pin. Careful selection of these resistors is crucial for achieving the desired output voltage and stability. The cathode must be connected to a voltage source higher than the desired regulated voltage.

Refer to the Texas Instruments datasheet for detailed electrical characteristics, application circuits, and recommended design practices.