Some Voltage Regulator Ciruits for Microcontroller based Projects

A regulated and noise-free power supply voltage is essential for microcontrollers and other components such as amplifiers, filters, and GPS devices. Voltage surges in the supply voltage can permanently damage embedded systems. A voltage regulator must maintain the output voltage above the desired value, even if the current drawn by the circuit increases. An appropriate voltage regulator circuit should keep the output voltage constant while delivering the necessary current to the connected circuit. This circuit generates a 5V output voltage from an input voltage ranging from 7V to 40V. The LM2576 is capable of driving a 3A load with excellent line and load regulation. The schematic diagram of the LM2576-based voltage regulator circuit is shown in Figure 1 below. It is a monolithic integrated circuit designed as an adjustable 3-terminal positive voltage regulator, capable of supplying over 1.5A of load current with an adjustable output voltage ranging from 1.2V to 37V. It features internal current limiting, thermal shutdown, and safe area compensation. The schematic diagram of the LM317-based voltage regulator is shown in Figure 2. This circuit is utilized to generate a 3.3V output voltage from a 12V input voltage for powering a multimedia card. The output voltage can be adjusted by varying the variable resistor RV2 shown in Figure 2. The LM7805 is a 3-terminal 1A positive voltage regulator, and the schematic diagram of the LM7805-based voltage regulator circuit for generating a 5V output voltage from a 12V input voltage is shown in Figure 3.

The LM2576 voltage regulator circuit is designed to provide a stable 5V output from a wide input voltage range of 7V to 40V, making it versatile for various applications. The circuit utilizes the LM2576, which is a step-down (buck) regulator capable of delivering up to 3A of output current. This capability ensures that the regulator can handle significant load requirements while maintaining low output voltage ripple and high efficiency. The internal features of the LM2576, including current limiting, thermal shutdown, and safe area compensation, protect the circuit from damage under fault conditions and ensure reliable operation.

The LM317 voltage regulator is another option for applications requiring adjustable output voltage. It can output voltages between 1.2V and 37V, making it suitable for a range of devices. The ability to adjust the output voltage using a variable resistor (RV2) allows for fine-tuning based on specific circuit requirements. This flexibility is particularly useful in applications like multimedia cards, where precise voltage levels are critical for optimal performance.

The LM7805 is a standard voltage regulator that provides a fixed 5V output at a maximum current of 1A. It is commonly used in various electronic projects and devices due to its simplicity and reliability. The schematic diagram for the LM7805 circuit illustrates how it can convert a 12V input into a stable 5V output, making it ideal for powering microcontrollers and other low-voltage components.

In summary, these voltage regulator circuits play a crucial role in ensuring that electronic systems operate reliably and efficiently, safeguarding sensitive components from voltage fluctuations and providing the necessary power for optimal functionality.a regulated and noise free power supply voltage for the microcntroller and other components like amplifiers, filters and GPS etc. , otherwise a voltage surge generated in the voltage being fed to the microcontroller and other components may permanently damage your embedded system.

A voltage regulator should not let the voltage being delivered to the c iruit drop down below the desired value in case if the amount of current being drawn by the ciruit increases. An appropriate voltage regulator circuit should keep the output volgate constant while delievring the current required by the ciruit to which voltage regulator supplying input voltage and current.

This circuit generates 5Volt Out put voltage from input voltage renaging from 7V-40V. LM2576 iscapable of driving 3A load withexcellent line and load regulation. The schematic diagram of LM2576 based Voltage Regulator circuit is shown in the Figure 1 below. It is a monolithic integrated circuit. It is an adjustable 3-terminalpositive voltage regulator. It is designed to supply more than 1. 5Aof load current with an output voltage adjustable over a voltage ranging from1. 2V to 37V. It employs internal current limiting, thermalshut-down and safe area compensation. The schematic diagram of LM317 based voltage regulator is shown in figure 2. I have utilized this circuit to generate 3. 3V out put voltage from 12V input voltage for input power supply of Multimedia Card. You can adjust the output voltage by varying the variable resistor RV2 shown in Figure 2. LM7805 is a 3-Terminal 1A Positive Voltage Regulator. The schematic digaram LM7805 based coltage regulator circuit for generating 5V output voltage from 12V input voltgage is shown in Figure 3. 🔗 External reference