Now you can isolate USB with a single chip!

The ADuM3160 and ADuM41601 are USB port isolators, based on Analog Devices iCoupler® technology. Combining high speed CMOS and monolithic air core transformer technology, these isolation components provide outstanding performance characteristics and are easily integrated with low and full speed USB-compatible peripheral devices.

Many microcontrollers implement USB so that it presents only the D+ and D− lines to external pins. This is desirable in many cases because it minimizes external components and simplifies the design; however, this presents particular challenges when isolation is required. USB lines must automatically switch between actively driving D+/D−, receiving data, and allowing external resistors to set the idle state of the bus. The ADuM3160/4160 provide mechanisms for detecting the direction of data flow and control over the state of the output buffers. Data direction is determined on a packet-by-packet basis.

The ADuM3160/4160 use the edge detection based iCoupler technology in conjunction with internal logic to implement a transparent, easily configured, upstream facing port isolator. Isolating an upstream facing port provides several advantages in simplicity, power management, and robust operation.

The isolator has propagation delay comparable to that of a standard hub and cable. It operates with the supply voltage on either side ranging from 3.1 V to 5.5 V, allowing connection directly to VBUS by internally regulating the voltage to the signaling level. The devices provides isolated control of the pull-up resistor to allow the peripheral to control connection timing. The deviced have a low idle current; a suspend mode is required.