LM2574MX-ADJ/NOPB

The LM2574xx series regulators are monolithic integrated circuits that provide all active functions for a step-down (buck) switching regulator, capable of driving a 0.5A load with excellent line and load regulation. These devices are available in 3.3V, 5V, 12V, 15V, and adjustable output versions. Requiring a minimum number of external components, these regulators are simple to use, featuring internal frequency compensation and a fixed-frequency oscillator. The LM2574xx series offers a high-efficiency alternative to popular three-terminal linear regulators. Due to its high efficiency, heat sinking is typically accomplished by the copper traces on the PCB alone. A range of optimized standard inductors for use with the LM2574 are available from several different manufacturers, greatly simplifying the design of switch-mode power supplies. Additional features include ±4% output voltage tolerance and ±10% oscillator frequency tolerance under rated input voltage and output load conditions. An external shutdown function is provided with a 50μA (typical) standby current. The output switch incorporates cycle-by-cycle current limiting and a thermal shutdown for full protection under fault conditions.

Applications

• Simple, efficient step-down regulator
• High-efficiency pre-regulator for linear regulators
• On-card switching regulator
• Positive-to-negative converter (buck/boost)

Key features

• 3.3V, 5V, 12V, 15V, and adjustable output versions
• Adjustable version output voltage range: 1.23V to 37V (57V for high-voltage version), with maximum ±4% tolerance under line and load conditions
• 0.5A rated output current
• Wide input voltage range: 40V, up to 60V for high-voltage version
• Only 4 external components required
• 52kHz fixed-frequency internal oscillator
• TTL shutdown, low-power standby mode
• High efficiency
• Compatible with off-the-shelf standard inductors
• Thermal shutdown and current limiting protection
• Create custom designs using LM2574 with WEBENCH Power Designer