EC9309 – 2A 150KHz PWM Buck DC/DC Converter

General description

The EC9309 is a series of easy to use fixed and adjustable step-down (buck) switch-mode voltage regulators. These devices are available in fixed output voltage of 3.3V, 5V, and an adjustable output version. Both versions are capable of driving a 2A load with excellent line and load regulation.Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation, and a fixed-frequency oscillator. The output voltage is guaranteed to ±3% tolerance under specified input voltage and output load conditions. The oscillator frequency is guaranteed to ±15%. External shutdown is included, featuring typically  80 μA standby current. Self protection features include a two stage frequency reducing current limit for the output switch and an over temperature shutdown for complete protection under fault conditions.The EC9309 is available in SOP-8 ,and DIP-8 packages.


  • 3V,5V and adjustable output Versions
  • Output adjustable from 1.23V to 43V
  • Fixed 150KHz frequency internal oscillator
  • Guaranteed 2A output load current
  • Input voltage range up to 45V
  • Low power standby mode, IQ typically 80 μA
  • TTL shutdown capability
  • Excellent line and load regulation
  • Requires only 4 external components
  • High efficiency
  • Thermal shutdown and current limit protection
  • Available in SOP-8 and DIP-8 packages


  • Simple High-efficiency step-down regulator
  • On-card switching regulators
  • Positive to negative converter
  • LCD monitor and LCD TV
  • DVD recorder and PDP TV
  • Battery charger
  • Step-down to 3.3V for microprocessors

Pin Configurations

Ordering info

Typical Applications circuit