The ADuM1400/ADuM1401/ADuM14021 are quad-channel digital isolators based on Analog Devices， Inc.， iCoupler? technology. Combining high speed CMOS and monolithic air core transformer technology， these isolation components provide outstanding performance characteristics superior to alternatives， such as optocoupler devices. By avoiding the use of LEDs and photodiodes， iCoupler devices remove the design difficulties commonly associated with optocouplers. The typical optocoupler concerns regarding uncertain current transfer ratios， nonlinear transfer functions， and temperature and lifetime effects are eliminated with the simple iCoupler digital interfaces and stable performance characteristics. The need for external drivers and other discrete components is eliminated with these iCoupler products. Furthermore， iCoupler devices consume one tenth to one sixth of the power of optocouplers at comparable signal data rates. The ADuM1400/ADuM1401/ADuM1402 isolators provide four independent isolation channels in a variety of channel configurations and data rates （see the Ordering Guide）。 All models operate with the supply voltage on either side ranging from 2.7 V to 5.5 V， providing compatibility with lower voltage systems as well as enabling a voltage translation functionality across the isolation barrier. In addition， the ADuM1400/ ADuM1401/ADuM1402 provide low pulse width distortion （《2 ns for CRW grade） and tight channel-to-channel matching （《2 ns for CRW grade）。 Unlike other optocoupler alternatives， the ADuM1400/ADuM1401/ADuM1402 isolators have a patented refresh feature that ensures dc correctness in the absence of input logic transitions and when power is not applied to one of the supplies.