Exar – XR75100: 40V Synchronous Step Down COT Controller Simplifies Point-of-Load Supply Designs


The XR75100 is a synchronous step down controller for point-of-load supplies up to 20A. A wide 5V to 40V input voltage range allows for single supply operation from industry standard 12V, 18V, and 24V DC and AC rails. The patented emulated current mode Constant On-Time (COT) control scheme provides extremely fast line and load transient response using ceramic output capacitors. It requires no loop compensation hence simplifying circuit implementation and reducing overall component count.


  • 20A capable step down controller
  • Integrated high current 2A/3A drivers
  • No loop compensation required
  • Ceramic output capacitor stable operation
  • Constant 100kHz to 800kHz frequency
  • Programmable current limit
  • 5.5V to 40V input voltage range
  • 0.6V adjustable output voltage
  • <0.01%/V line regulation
  • Programmable 200ns-2μs on-time
  • Selectable CCM or CCM/DCM operation
  • 1k MSRP: $1.59