The LM2576 series voltage regulator is a monolithic integrated circuit, ideal for simple and convenient design of step-down switching voltage regulators (step-down converters). All circuits in the series are capable of driving 3.0a loads with excellent line and load regulation capabilities. These regulators are designed to minimize the number of external components to simplify the power supply design. And there are fixed output voltage 3.3V, 5.0V, 12v, 15v and adjustable output versions.
Features of the LM2576 include a guaranteed tolerance of ±4% of output voltage at specified input voltage and output load conditions, and a ±10% oscillator frequency (0°C to 125°C±2%). Including external shutdown, with 80 A(typical) standby current. Output switches include cyclic current limiting, as well as thermal shutdown, for full protection under failure conditions.
The standard series of inductors optimized for the LM2576 are offered by several different inductor manufacturers. Because the LM2576 converter is a switch-mode power supply, its efficiency is significantly improved compared to popular three-terminal linear regulators, especially at higher input voltages.
In many cases, the dissipated power is so low that a radiator is not needed, or its size can be greatly reduced. A standard series of inductors optimized for LM2576 is available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.
Typical Application (Fixed Output Voltage Versions)
Block Diagram
Typical Test Circuit
Fixed output voltage version
Adjustable output voltage version
Features
● 3.3V, 5.0V, 12v, 15v and adjustable output versions
● Adjustable version output voltage range, 1.23 to 37 V±4% Maximum overline and load conditions
● Ensure 3.0 output current
● Wide input voltage range
● Only 4 external components are required
● 52 kHz fixed frequency internal oscillator
● TTL shutdown capability, low power standby mode
● High Efficient
● Use off-the-shelf standard inductors
● Hot shutdown and current limiting protection
● Humidity Sensitivity Level (MSL) = 1
● Pb− provides free software packages
Applications
● Simple and efficient Buck regulator
● High efficiency preregulator of linear voltage regulator
● Switch the regulator On−Card
● Buck-Boost
● Negative boost converter
● Power to the battery charger
