LM2576S-3.3/NOPB

The LM2576 series regulators are monolithic ICs that provide all active functions for a step-down switching regulator, capable of driving 3A loads with excellent line and load regulation. These devices are available in 3.3V, 5V, 12V, 15V fixed output voltages and an adjustable output version. These regulators require minimal external components, are easy to use, and feature fault protection and a fixed-frequency oscillator. The LM2576 series offers a high-efficiency alternative to popular three-terminal linear regulators, significantly reducing heatsink size and eliminating the need for a heatsink in some cases. Standard series inductors optimized for use with the LM2576 are available from several different manufacturers, greatly simplifying switching mode power supply design. 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 standby current (typical) of 50 μA. The output switch incorporates cycle-by-cycle current limiting and thermal shutdown for full protection under fault conditions. The new LMR33630 offers lower BOM cost, higher efficiency, smaller solution size (85% reduction), and many additional features. The LM76003 requires minimal external components, with a pin assignment designed to simplify PCB layout while providing better EMI and thermal performance.

Applications

• Motor drivers
• Commercial networking and server PSUs
• Appliances
• Test and measurement equipment

Key features

• Updated product versions available: LMR33630 36V, 3A, 400kHz synchronous converter; LM76003 60V, 3.5A, 2.2MHz synchronous converter
• 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
• Rated output current: 3A
• Wide input voltage range: 40V, up to 60V for high-voltage version
• Only four external components required
• 52kHz fixed-frequency internal oscillator
• TTL shutdown, low-power standby mode
• High efficiency
• Compatible with off-the-shelf standard inductors
• Create custom designs using LMR33630 or LM76003 with WEBENCH Power Designer