LM2576T-3.3(XBLW)

The LM2576 series of regulators are monolithic integrated circuit that provides all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. The LM2576 available in fixed output voltages of 3.3V, 5V, 12V and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator. The LM2576 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases no heat sink is required. 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. Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 μA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions. The LM2576 is available in T0220-5 and T0263-5 package.

Applications

• Simple high-efficiency step-down (buck) regulator
• Efficient pre-regulator for linear regulators
• On-card switching regulators
• Positive to negative converter (Buck-Boost)

Key features

• 3.3V, 5V, 12V and adjustable output versions
• High efficiency
• Guaranteed 3A output current
• Requires only 4 external components
• 52 kHz fixed frequency internal oscillator
• TTL shutdown capability, low power standby mode
• Uses readily available standard inductors
• Thermal shutdown and current limit protection
• Adjustable version output voltage range, 1.23V to 37V ±4% max over line and load conditions