Descriptions: A Class LM2576 LM 2576 Adjustable Voltage Regulator Buck IC Max Input 40V Output 1.23 To 37V Step Down
A Class LM2576 LM 2576 Adjustable Voltage Regulator Buck IC Max Input 40V Output 1.23 To 37V Step Down Voltage Regulator IC 5 Pin TO-220-5 Package Switching Voltage Regulator
The LM2576 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step−down switching regulator (buck converter). All circuits of this series are capable of driving a 3.0 A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5.0 V,12 V, 15 V, and an adjustable output version.
These regulators were designed to minimize the number of external components to simplify the power supply design. Standard series of inductors optimized for use with the LM2576 are offered by several different inductor manufacturers. Since the LM2576 converter is a switch−mode power supply, its efficiency is significantly higher in comparison with popular three−terminal linear regulators, espely with higher input voltages.
In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2576 are available from several different manufacturers. This feature greatly simplifies the design of switch−mode power supplies.
The LM2576 features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and±10% on the oscillator frequency (±2% over 0°C to 125°C). External shutdown is included, featuring 80 A (typical) standby current. The output switch includes cycle−by−cycle current limiting, as well as thermal shutdown for full protection under fault conditions.
- Adjustable Version Output Voltage Range,1.23V to 37V (57V for HV Version) ±4% Max Over Line and Load Conditions
- Specified 3A Output Current
- Wide Input Voltage Range, 40V Up to 60V for HV Version
- Requires Only 4 External Components
- 52 kHz Fixed Frequency Internal Oscillator
- TTL Shutdown Capability, Low Power Standby Mode
- High Efficiency
- Uses Readily Available Standard Inductors
- Thermal Shutdown and Current Limit Protection
LM2576 Regulator Specifications:
- Switch mode step down voltage regulator
- Output Voltage for fixed voltage regulator: 3.3V, 5V, 12V or 15V
- Output Voltage for Variable type regulator: 1.23V to 37V
- Output Current: Upto 3A
- Maximum Input Voltage: 40V
- In-built Thermal Shutdown and Current Limit Protection
- Internal Oscillator: 52-kHz (Fixed Frequency)
- Available in TO-220 and TO-263 packages
Alternatives Step-Down Converter IC
Where to use LM2576 Buck Converter IC?
The LM2576 is a voltage Regulator IC, it uses the Buck-converter topology to step-down and regulate higher level voltage values to lower level. It is of non-sync type and can take in an input voltage 40V maximum and source an output current of 3A maximum with a peak efficiency of 90%.
There are also fixed output voltage type and variable output voltage type of Converters available with the same IC. So if you are looking for a switching step-down regulator with these characteristics to regulate a voltage for your circuit then this IC might be of interest to you.
How to use LM2576 IC?
Using the LM2576 is very easy; it requires only 6 additional components including an inductor which is placed in series with the output. The value of the inductor can range from 47uH to 330uH based on the output required. A typical application circuit for LM2576 is show below.
Since this is a switching circuit electrostatic interference should be kept in mind while designing the PCB of placing the components on a perf board. The circuit also deals with high current and hence a suitable high voltage di-electric capacitor with low ESR (equivalent series resistance) should be chosen. Also a high current will be passing through the indictor and hence the coil should be of high gauge to allow the current to pass through it. Using a wrong value or low wattage inductor might damage the IC permanently.
The diode 1N5822 is a Schottky diode which can be used with the high switching speed of the regulator IC since it operates at 52kHz. Also the voltage drop across the diode is less and can allow high current to pass through it. Again since we are dealing with step-down switching circuit there will high power dissipation and the use of heat sink for the LM2576 is mostly mandatory.
- Used in battery circuits since they have high efficiency
- Step-down Linear regulators
- Used in small SMPS circuits
- Can also be used to source negative voltage.
- 1 xA Class LM2576 LM 2576 Adjustable Voltage Regulator Buck IC Max Input 40V Output 1.23 To 37V Step Down Voltage Regulator IC 5 Pin TO-220-5 Package Switching Voltage Regulator