EVAL-CN0160-EB1Z: Isolated USB Port

This application isolates a peripheral device that already supports a USB interface. Because the peripheral is not explicitly defined in this circuit, power to run the secondary side of the isolator has been provided as part of the solution. If the circuit is built onto the PCB of a peripheral design, power could be sourced from the peripheral’s off line supply, a battery, or the USB cable bus power, depending on the needs of the application.

The application circuit shown is typical of many medical and industrial applications.

The ADuM4160 provides an inexpensive and easy to implement isolation buffer for medical and industrial peripherals. The challenges that need to be met are:

• 1. Isolate directly in the USB D+ and D− lines allowing the use of existing USB infrastructure in microprocessors.
  

• 2. Implement an automatic scheme for data flow of control that does not require external control lines.
  

• 3. Provide medical grade isolation.
  

• 4. Allow a complete peripheral to meet the USB-IF certification standards.
  

• 5. Support full speed (12 Mbps) and low speed (1.5 Mbps) signaling rates.
  

• 6. Support flexible power configurations.