LM2574

• New product available: TPS560430, 36-V, 600-mA synchronous step-down converter
• 3.3-V, 5-V, 12-V, 15-V, and adjustable output versions
• Adjustable version output voltage range: 1.23 V to 37 V (57 V for HV version) ±4% maximum over line and load conditions
• Specified 0.5-A output current
• Wide input voltage range: 40 V, up to 60 V for HV Version
• Requires only four external components
• 52-kHz Fixed-frequency internal oscillator
• TTL shutdown capability, low-power standby mode
• High efficiency
• Uses readily available standard inductors
• Thermal shutdown and current-limit protection
• Create a custom design using the LM2574 with the WEBENCH^® Power Designer

The LM2574xx series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 0.5-A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, 15 V, 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 LM2574xx series offers a high-efficiency replacement for popular three-terminal linear regulators. Because of its high efficiency, the copper traces on the printed-circuit board (PCB) are normally the only heat sinking needed.

A standard series of inductors optimized for use with the LM2574 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.

Other features include a specified ±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 TPS560430 is a newer generation buck converter, being functionally equivalent to LM2574. It offers reduced BOM cost, increased efficiency, and reduced solution size. See the Device Comparison Table to compare specifications. Start WEBENCH Design with TPS560430.