LM2576T-12

The LM2576 series switching regulators are monolithic integrated circuits that provide all the functions required for a step-down (buck) switching regulator, capable of driving a 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, and 15V, as well as an adjustable output version. The switching regulators include an internal frequency compensator and a fixed-frequency oscillator, minimizing the number of external components for ease of use. The LM2576 offers significantly higher efficiency than popular three-terminal linear regulators, making it an ideal replacement. In most cases, no external heat sink or only a minimal one is required. Standard inductor series optimized for use with the LM2576 are available from inductor suppliers, greatly simplifying switching power supply design. Additional features include: guaranteed output voltage accuracy of 1 ± 4% and oscillator frequency accuracy of ±12% under specified input voltage and output load conditions, an external shutdown circuit with a typical standby current of 50 μA. The output switch incorporates cycle-by-cycle current limiting and a thermal shutdown function that provides complete protection under fault conditions.

Applications

• Simple, high-efficiency step-down regulator
• High-efficiency pre-regulator for linear regulators
• Positive-to-negative converter
• Negative boost converter
• Battery charger/power adapter

Key features

• 3.3V, 5V, 12V, 15V, and adjustable output voltage versions
• Adjustable output versions: output voltage range 1.23~37V (57V for HV versions) over line and load conditions, max error ±4%
• Guaranteed 3.0A output current
• Wide input voltage range: 40V to 60V for HV versions
• Only 4 external components required
• 52kHz fixed-frequency internal oscillator
• TTL shutdown capability, micropower standby mode
• High efficiency
• Compatible with standard off-the-shelf inductors
• Thermal shutdown and current limiting protection