XL2594-5.0

The XL2594xx 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, and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and feature internal frequency compensation, a fixed- frequency oscillator, and improved line and load regulation specifications. A standard series of inductors (both through-hole and surface-mount types) are available from several different manufacturers optimized for use with the XL2594xx series. This feature greatly simplifies the design of switch- mode power supplies. Other features include an ensured ±4% tolerance on output voltage under all conditions of input voltage and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring typically 85-μA standby 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.

Applications

• Simple high-efficiency step-down (buck) regulator
• Efficient preregulator for linear regulators
• On-card switching regulators
• Positive-to-negative convertor

Key features

• 3.3-V, 5-V, 12-V, and adjustable output versions
• Ensured 0.5-A output current
• Input voltage range up to 40 V
• Requires only four external components
• 150-kHz fixed-frequency internal oscillator
• TTL shutdown capability
• Low power standby mode, IQ typically 85 μA
• High efficiency
• Uses readily-available standard inductors
• Thermal shutdown and current-limit protection