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UA78M33CDCYR – 3.3V 500mA Low Dropout Voltage Regulator – Texas Instruments

Ensure stable power delivery in your designs with the UA78M33CDCYR LDO voltage regulator from Texas Instruments. This high-performance component provides precise 3.3V output for sensitive electronics, featuring thermal protection and wide input voltage tolerance. Ideal for space-constrained applications requiring reliable voltage conversion with minimal dropout.

Key Features

• Fixed 3.3V Output with ±2% accuracy
• 500mA Continuous Output Current capacity
• Low Dropout Voltage: 2V max @ 350mA
• Wide Input Range: Up to 25V DC
• Enhanced Protection: Over-current, over-temperature, and short-circuit safeguards
• High PSRR: 80dB noise rejection at 120Hz

Technical Specifications

• Package: SOT-223-4 surface-mount (TO-261AA compatible)
• Operating Temperature: 0°C to 125°C industrial range
• Output Configuration: Single positive regulator
• Dropout Characteristics: Optimized for battery-powered systems
• Status: Active production (Texas Instruments)

Typical Applications

• Industrial control systems and PLCs
• IoT devices and wireless modules
• Automotive infotainment systems
• Medical monitoring equipment
• Consumer electronics power management

About Texas Instruments

Texas Instruments (TI) stands as a global semiconductor leader with over 90 years of innovation in analog and embedded processing technologies. Their voltage regulation solutions set industry benchmarks for precision, efficiency, and reliability across automotive, industrial, and consumer markets.

TI maintains rigorous quality control through vertically integrated manufacturing, ensuring component consistency and long-term availability. Their extensive R&D investment delivers cutting-edge thermal management and power efficiency technologies, making TI regulators the preferred choice for mission-critical designs.

About LDO Voltage Regulators

Low Dropout (LDO) regulators maintain stable output voltages even when input voltage approaches the output level, making them essential for battery-operated devices and noise-sensitive circuits. Unlike switching regulators, LDOs provide ripple-free output without electromagnetic interference, simplifying PCB layout and reducing component count.

Modern LDOs like the UA78M33 series integrate critical protection features that prevent system damage during voltage spikes or thermal stress. Their compact form factors enable deployment in space-constrained applications where stable voltage references are crucial for microcontroller operation, sensor accuracy, and signal integrity.

Packaging Options

• Tape & Reel (TR) – Automated assembly
• Cut Tape (CT) – Prototyping quantities
• Digi-Reel® – Custom reel lengths

Frequently Asked Questions

Question: What is the typical dropout voltage at full 500mA load?
Answer: While dropout reaches 2V maximum at 350mA, expect approximately 1.5V dropout at 500mA with 25°C ambient temperature.

Question: Does this regulator require external capacitors?
Answer: Yes, a 0.33μF input capacitor and 0.1μF output capacitor are recommended for stability. Refer to the datasheet for layout guidelines.

Question: Is the UA78M33CDCYR suitable for automotive applications?
Answer: While it operates in industrial temperature ranges (-40°C to 125°C), verify against specific AEC-Q100 requirements for automotive use cases.

Question: Can multiple regulators share a common heatsink?
Answer: Thermally connect packages only if electrically isolated, as the tab connects to V_OUT. Use insulating pads for multi-regulator designs.

Question: How does PSRR affect my power supply design?
Answer: The 80dB PSRR at 120Hz significantly attenuates input ripple, making this LDO ideal for noisy supply rails from AC/DC converters or motors.

Question: What distinguishes LDOs from standard linear regulators?
Answer: LDOs maintain regulation with input-output differentials under 1V, whereas traditional linear regulators typically require ≥2V headroom for stable operation.

Product images are representational only. Refer to datasheets for exact specifications.

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