STMicroelectronics LD1117V33 3.3 V 800 mA LDO Voltage Regulator – TO-220

The STMicroelectronics LD1117V33 is a low-dropout linear regulator designed to provide a stable 3.3 V output with a current capability of up to 800 mA.

Its TO-220 package is suitable for through-hole mounting and allows a heatsink to be installed when required by the power dissipation. Integrated thermal protection and internal current limiting help protect both the regulator and the connected circuit.

With a typical dropout voltage of approximately 1 V, the regulator is suitable for powering digital circuits, microcontrollers, communication modules, electronic equipment and linear power supplies.

A minimum 10 µF output capacitor is recommended to ensure regulator stability.

Main features

• Manufacturer: STMicroelectronics
• Part number: LD1117V33
• Type: positive linear LDO regulator
• Configuration: fixed output voltage
• Output voltage: 3.3 V
• Guaranteed output current: up to 800 mA
• Typical output current under test conditions: 950 mA
• Maximum input voltage: 15 V DC
• Typical dropout voltage: approximately 1 V
• Maximum dropout at 800 mA: 1.2 V
• Output tolerance at 25 °C: ±1%
• Full operating range tolerance: approximately ±2%
• Typical quiescent current: 5 mA
• Supply voltage rejection: 75 dB typical
• Minimum output capacitor: 10 µF
• Thermal protection: integrated
• Current limiting: integrated
• Operating junction temperature: 0 to 125 °C
• Package: TO-220
• Number of pins: 3
• Mounting type: through-hole
• Quantity: 1 piece

Pin configuration

With the marked face pointing forwards and the leads pointing downwards:

• Pin 1: GND
• Pin 2: VOUT – 3.3 V output
• Pin 3: VIN – input
• Metal tab: electrically connected to VOUT

Recommended applications

• 3.3 V linear power supplies
• Microcontrollers and digital circuits
• Communication modules
• Arduino, ESP and experimental electronics projects
• Radio and telecommunications equipment
• 5 V to 3.3 V conversion
• Electronic equipment repair and development

Important note

The input voltage must exceed the output voltage by at least the regulator dropout voltage. For high-current operation, an input of approximately 4.5 to 4.75 V or higher is recommended.

Power dissipation is approximately calculated as (VIN − 3.3 V) × load current. A suitable heatsink may be required when there is a significant difference between the input and output voltages.

The metal tab is connected to the 3.3 V output. Electrical insulation may be required when mounting the regulator on a heatsink shared with other components.