DESCRIPTION
The LM2575HVT-ADJ series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation. These devices are available in fixed output
voltages of 3.3V, 5V, 12V, 15V, 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 LM2575HVT-ADJ series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required.
A standard series of inductors optimized for use with the LM2575HVT-ADJ 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.
FEATURES
• 3.3V, 5V, 12V, 15V, and Adjustable Output Versions
• Adjustable Version Output Voltage Range, – 1.23V to 37V (57V for HV Version) ±4% Max Over
– Line and Load Conditions
• Specified 1A Output Current
• Wide Input Voltage Range, 40V up to 60V for HV Version
• Requires Only 4 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
• P+Product Enhancement Tested
APPLICATIONS
• Simple High-Efficiency Step-Down (Buck) Regulator
• Efficient Pre-Regulator for Linear Regulators
• On-Card Switching Regulators
• Positive to Negative Converter (Buck-Boost)
Feature
- Adjustable With a Range of 1.23 V to 37 V and
±4% Regulation (Max) Over Line, Load, and
Temperature Conditions - Specified 1-A Output Current
- Wide Input Voltage Range 4.75 V to 40 V
- Uses Readily Available Standard Inductors
- 52-kHz (Typical) Fixed-Frequency Internal
Oscillator - TTL Shutdown Capability With 50-μA (Typical)
Standby Current - High Efficiency…as High as 88% (Typical)
- Thermal Shutdown and Current-Limit Protection
With Cycle-by-Cycle Current Limiting - For the Full Offering of Voltages (Including Fixed-
Output Options) and Packages (Including TO-
263), See TL2575 Data Sheet, SLVS638
