The UPC78L05 is a 3-terminal positive voltage regulator manufactured by NEC (now Renesas Electronics). It is designed to provide a stable and regulated 5V output voltage from a higher input voltage. This is a low-current version of the 7805 series, making it suitable for applications where space and power efficiency are critical.

Applications

• Low-Power Microcontroller Power Supplies: Providing a stable 5V for low-power microcontrollers and embedded systems where current draw is minimal.
• Portable Electronics: Used in devices like small radios, calculators, and personal digital assistants (PDAs) due to its small size and low power consumption.
• Battery-Powered Devices: Regulating voltage in battery-operated equipment to ensure consistent performance as the battery discharges.
• Logic Circuit Power: Regulating voltage for low-power TTL and CMOS logic circuits.
• Sensor Power Supplies: Supplying regulated power to sensors in various applications.

Features

• Fixed 5V Output: Delivers a stable 5V output voltage.
• Output Current: Typically provides up to 100mA output current.
• Input Voltage Range: Operates with input voltages ranging typically from 7V to 20V.
• Internal Short-Circuit Current Limiting: Protects the regulator and connected circuitry from damage due to short circuits.
• Thermal Overload Protection: Shuts down the regulator when its internal temperature exceeds a safe limit, preventing overheating.
• Small Package Size: Available in small packages like TO-92 or SO-8, suitable for compact designs.
• 3-Terminal Package: Easy to use with only three terminals (Input, Output, Ground).

Benefits

• Stable and Regulated Power: Provides a consistent 5V output, ensuring reliable operation of connected circuits.
• Overload Protection: Protects against short circuits and excessive current draw, preventing damage to the regulator and connected components.
• Thermal Protection: Prevents overheating and potential damage due to excessive power dissipation.
• Small Size: Suitable for applications where space is limited.
• Low Power Consumption: Efficient voltage regulation for battery-powered devices.
• Cost-Effective: An affordable solution for voltage regulation in low-current applications.

Additional Details

The UPC78L05 is commonly available in TO-92 and SO-8 packages. Because it is a low-current regulator, significant heat sinking is usually not required in typical applications. The device requires a minimum input voltage (typically around 7V) to function correctly. It's important to observe the absolute maximum input voltage rating (usually around 30V) to avoid damaging the regulator. For optimal performance, it's recommended to include bypass capacitors (e.g., 0.33uF on the input and 0.1uF on the output) close to the regulator to improve stability and transient response. It is important to consult the Renesas Electronics datasheet for specific operating conditions, application notes, and thermal considerations. Be aware that alternative manufacturers may have slightly different electrical specifications and performance characteristics. The low quiescent current and compact package makes this ideal for low-power and portable applications.