Diotec Semiconductor LDI1117-3.3H 3.3 V 1 A LDO Voltage Regulator

Introduction

The Diotec Semiconductor LDI1117-3.3H is a fixed-output low-dropout (LDO) voltage regulator designed to provide a stable 3.3 V supply rail from a higher DC input voltage. With output-current capability up to 1 A and a compact SOT-223 surface-mount package, it is well suited to embedded electronics and compact power-conversion designs.

Part Description

The LDI1117-3.3H is a positive linear voltage regulator with a fixed 3.3 V output. It belongs to the widely used 1117-style LDO regulator family, making it a practical choice for generating 3.3 V logic power from sources such as 5 V adapters, USB-derived rails, batteries, or intermediate DC supply rails.

Its low-dropout design allows the regulator to maintain output regulation even when the input voltage is only moderately higher than the required 3.3 V output. The device can supply loads of up to 1 A, subject to input voltage, thermal design, PCB copper area, and operating conditions.

Integrated thermal-overload protection helps protect the regulator if excessive junction temperature occurs, while short-circuit protection provides an added layer of robustness during output faults. The SOT-223 package supports surface-mount assembly and uses its tab area to help transfer heat into the PCB copper.

Applications

Potential applications for the LDI1117-3.3H include:

• 5 V to 3.3 V power conversion
• Microcontroller and development-board power rails
• Wi-Fi, Bluetooth, and wireless-module supplies
• FPGA, CPLD, and digital logic support rails
• Sensor interface and measurement circuits
• Embedded Linux single-board computer accessories
• USB-powered 3.3 V devices
• Industrial control electronics
• Communication and networking hardware
• Consumer electronic products
• Battery-powered systems with suitable input voltage
• Local post-regulation after a switching power supply

Industries

The LDI1117-3.3H may be used in a variety of industries, including:

• Consumer electronics
• Industrial automation
• Internet of Things (IoT)
• Telecommunications
• Networking equipment
• Automotive auxiliary electronics
• Smart-home devices
• Test and measurement equipment
• Medical and laboratory instrumentation
• Educational electronics and prototyping
• Security and access-control systems
• Robotics and embedded systems

Usage Ideas

1. USB-Powered Microcontroller Board
   Use the regulator to convert a 5 V USB input into a regulated 3.3 V supply for a microcontroller, sensors, and communication modules.

2. 3.3 V Wireless Sensor Node
   Create a compact sensor module powered from a 5 V source, using the LDI1117-3.3H to supply a Wi-Fi or Bluetooth module and low-power environmental sensors.

3. Switching Regulator Cleanup Stage
   Place the device after a higher-voltage switching supply to create a quieter 3.3 V rail for analog sensors, ADC circuits, or sensitive communication electronics.

Conclusion

The Diotec Semiconductor LDI1117-3.3H is a practical fixed 3.3 V LDO regulator for designs requiring up to 1 A of regulated output current. Its compact SOT-223 package, low-dropout operation, and built-in thermal and short-circuit protection make it a useful power-management component for embedded, industrial, consumer, and communication-focused electronics.