What is LM2576 Voltage Regulator & Its Working

The LM2576 voltage regulator is a monolithic IC that is suited ideally for a simple buck converter design which is also known as a step−down switching regulator. This series of regulators in all the circuits are used for driving a 3.0A of load through an outstanding line & load regulation. These regulators are available with fixed or adjustable voltages.

These regulators are mainly designed for reducing the exterior components to abridge the design of the power supply. As compared to 3 terminal linear regulators, the LM256 voltage regulator’s efficiency is considerably higher, particularly through maximum input voltages.

What is the LM2576 Voltage Regulator?

LM2576 is one kind of voltage regulator and it is also called a buck converter. This is mainly used like a pre-regulator within the linear regulators. This kind of regulator is a modified version of switching power supplies wherever it includes all functions required to decrease the voltage of the circuit. This buck converter includes an IC to drive the load below 1A.

LM2576 voltage regulator is obtainable through extraordinary load regulation as well as load line. This regulator is available in two versions where the first version comes with permanent output voltage & the second version comes with variable o/p so that we can select the required output.

This voltage regulator is a DC to DC converter that is used to decrease the input supply voltage to its o/p load. The flow of current will be enhanced when the voltage regulation occurs. This regulator is available through an oscillator with fixed-frequency approximately 52 kHz & also available through an integral frequency compensation technique.

This technique is mainly used for reducing the vibration & oscillation within the circuits. For this technique, RC networks are used to work properly. This regulator is accessible through the option like manual shutdown with an exterior ON/OFF pin apart from the line regulation & excellent load.

Pin Configuration

The pin configuration of the LM2576 voltage regulator is shown below. This IC includes five pins where each pin and its functionality are discussed below. Before using it, it is very essential to know about the functionality of each pin.

Pin 1(Vin): The voltage which has to be adjusted can be provided like an input to this Vin pin

Pin2 (Output): This output pin is mainly used to get the controlled signal output.

Pin3 (GND): The GND pin is mainly connected to the GND pin of the circuit.

Pin4 (Feedback): This feedback input pin is mainly used to fix the o/p voltage in case of changeable output. To regulate the o/p voltage, it is allied to the center of the feedback divider circuit. In a fixed output case, this pin is connected to the capacitor.

Pin5 (ON/OFF): ON/OFF pin is the input enable pin. This pin is connected to the GND to allow the voltage regulator. To disable the voltage regulator, this pin is connected to HIGH logic.

Features & Specifications

The features and specifications of the LM2576 voltage regulator include the following.

• This voltage regulator includes fixed frequency voltage with 52 kHz of the internal oscillator of frequency.
• Available packages are TO-220 &TO-263
• This voltage regulator provides permanent o/p voltages like 3.3V, 5V, 12V & 15V.
• In-built current limit protection & thermal shutdown
• The o/p voltage can be changed from 1.23V to 37V by connecting exterior components.
• Input voltage max is 40V
• It can resist a ±4% of tolerance on o/p voltage once the i/p voltage is in the specified range & output load conditions are satisfied & ±10% tolerance on the frequency of the oscillator.
• For variable type voltage regulator, output voltage ranges from 1.23V – 37V
• The specified output current is upto 3A
• It includes an under-voltage lockout circuit that maintains the i/p voltage within a range & maintains the regulator off till it reaches a fixed threshold level.

Alternative and Equivalent LM2576 voltage regulators are CS51411, LM1117, LM7912 & LM723.

LM2576 Voltage Regulator Circuit

The circuit diagram of the LM2576 voltage regulator circuit is shown below. This IC is used to build a switching regulator with 5V 3A. This circuit uses some basic electronic components like LM2576IC, IN5822 diode, 100uF inductor, 1000uf & 100 uf capacitors, etc.

This circuit is very simple to design for power digital circuits. It requires a power supply of 5V 2A. Because it is a digital circuit that uses a 10-watts high power. The power supply required for this circuit is 5V 3A. Once this circuit is used in cars, the power for the circuit can be used from the cigarette lighter of a car. However it works with 12V, so for circuit operation, we need to reduce the voltage to 5V with 3 Amp.

This IC maintains a stable voltage like 5 V & current 3A so it is compatible with any device simply. This circuit is very simple to use as it uses four main components like 100uF C1, 1N5822 D1, 100uH L1 & 1000uF C2. The input voltage of this circuit ranges from 7V to 40V and runs with high frequency.

This IC will not get heat due to the inbuilt cooler, so it can be used for a long time continuously. Additionally, we can also alter the different integrated circuits. For different ICs, the voltage level may vary like LM2576 with 3.3Vdc o/p, LM2576 with 5Vdc o/p, LM2576 with 12Vdc o/p, LM2576 with 15Vdc o/p & LM2576 ranges from 1.23Vdc – 37Vdc output.

Where to use LM2576 Voltage Regulator/Applications

The LM2576 voltage regulator uses Buck-converter to step down & change the voltage values from max to low range. So, it is one of the non-sync type regulators that uses max 40V input voltage & gives max 3A of current through 90% of peak efficiency.

There are different types of converters available with the same IC like fixed voltage & variable voltage type. So if you are looking for a regulator with these characteristics for changing the voltage for your application then the LM2576 voltage regulator is suitable.

The LM2576 voltage regulator provides an outstanding line & load regulation. This regulator drives 3A loads. Because of its suitable use, it is used as a step-down switching regulator.

It uses readily accessible inductors to make this IC perfect for SMPS designing because it simplifies its design greatly. This IC is suitable if you want to drive 3A loads & provides an o/p in the range of 1.23V- 37V with an 88% of efficiency then this IC is apt.

• LM2576 voltage regulator is used in battery circuits because they include high efficiency
• It is used to change a +ve input voltage to negate o/p voltage
• Used in step-down linear regulators & tiny SMPS circuits
• It is an efficient pre-regulator for designing Linear Regulators
• For battery chargers, it provides power supply
• Used in negative step upconverters
• Used in buck-boost converters
• This voltage regulator is used to design SMPS (switch-mode power supplies)

Thus, this is all about an overview of the voltage regulator like the LM2576 buck converter. This kind of voltage regulator provides a stable o/p voltage. The output voltage of this IC can be modified from 1.23V – 37V voltage range with exterior components. So, this chip is extremely easy to utilize & this feature will make it perfect for a broad range of applications. Here is a question for you, what are the different types of voltage regulators available in the market?