L78L05ACUTR

Product Overview

The L78L05ACUTR from STMicroelectronics is a surface-mount linear voltage regulator that provides a fixed positive 5 V output from a single regulator channel. It is used for compact power conversion tasks where a low-current regulated rail is required, with a maximum input voltage of 30 V and an output current rating of 100 mA. The device is housed in an SOT-89-3 package, also designated TO-243AA, and supports over-current, over-temperature, and short-circuit protection functions.

Key Features

• Fixed positive 5 V output delivered by one linear regulator channel for low-current regulated supply rails.
• Maximum input voltage of 30 V and output current capability of 100 mA, with quiescent current specified at 5.5 mA and maximum supply current at 6 mA.
• PSRR of 49 dB at 120 Hz helps reduce input ripple seen at the regulated output.
• Integrated protection features include over-current, over-temperature, and short-circuit protection.
• Surface-mount SOT-89-3 package, also designated TO-243AA, provides a compact footprint for board-level integration, with operating temperature range from 0°C to 125°C.

Applications

• Low-current 5 V supply rails for microcontrollers, logic circuits, or general digital subsystems powered from a higher DC input.
• Regulated 5 V rail for analog sensor interfaces or small measurement modules that require a fixed positive supply with modest current.
• Simple linear regulation in compact embedded boards that need a small surface-mount footprint and integrated over-current, over-temperature, and short-circuit protection.

Design & Procurement Notes

Designers should verify that the available input voltage remains below the 30 V maximum while leaving sufficient headroom for the fixed 5 V output and the 100 mA load current. The 5.5 mA quiescent current and 6 mA maximum supply current should be included in power budget calculations, particularly in low-current supply paths. Because the device is a linear regulator, input-to-output voltage difference and load current directly influence dissipation, so thermal layout around the SOT-89-3 package should be considered within the 0°C to 125°C operating range.