LM2595

• 3.3-V, 5-V, 12-V, and Adjustable Output Versions
• Adjustable Version Output Voltage Range, 1.2 V
  to 37 V ±4% Maximum Over Line and Load
  Conditions
• Available in TO-220 and TO-263 Surface-Mount
  Packages
• Ensured 1-A Output Load Current
• Input Voltage Range Up to 40 V
• Requires Only 4 External Components
• Excellent Line and Load Regulation Specifications
• 150-kHz Fixed-Frequency Internal Oscillator
• TTL Shutdown Capability
• Low Power Standby Mode, I_Q, Typically 85 µA
• High Efficiency
• Uses Readily Available Standard Inductors
• Thermal Shutdown and Current-Limit Protection

The LM2595 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1-A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 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 LM2595 series operates at a switching frequency of 150 kHz, thus allowing smaller-sized filter components than what would be needed with lower-frequency switching regulators. Available in a standard 5-pin TO-220 package with several different lead bend options, and a 5-pin TO-263 surface-mount package. Typically, for output voltages less than
12 V, and ambient temperatures less than 50°C, no heat sink is required.

A standard series of inductors are available from several different manufacturers optimized for use with the LM2595 series. This feature greatly simplifies the design of switch-mode power supplies.

Other features include a ±4% tolerance on output voltage under specified input voltage and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring typically 85-µA stand-by current. Self protection features include a two stage frequency reducing current limit for the output switch and an overtemperature shutdown for complete protection under fault conditions.