Full/Low Speed USB Digital Isolator

الوصف

The ADuM****1is a USB-port isolator, based on Analog

Devices, Inc. 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. Since the USB lines must switch between

actively driving D+/D- and allowing external resistors to set the

state of the bus, the ADuM***0 provides mechanisms for

detecting the direction of data flow and control over state of the

output buffers. Data direction is determined on a packet by

packet basis.

The ADuM***0 uses the edge detection based iCoupler

technology in conjunction with internal logic to implement a

transparent, easily configured, up-stream facing port isolator.

Isolating the up-stream port provides several advantages in

simplicity, power management and robust operation. 

The isolator has propagation delay comparable that of a

standard hub and cable. It operates with the supply voltage on

either side ranging from 3.0 V to 5.5 V, allowing connection

directly to VBUS by internally regulating the voltage to the

signaling level. The ADuM***0 provides isolated control of the

pull-up resistor to allow the peripheral to control connection

timing. The device draws low enough idle current that a

suspend state is not required.