Cmos digital isolator drivers#
iCoupler technology eliminates the uncertain current transfer ratios, nonlinear transfer functions, and drift (with time and temperature) associated with optocouplers reduces power consumption by as much as 90% and eliminates the need for external drivers or discrete devices. Wafer-scale processing provides a low-cost method for integrating multiple isolation channels, as well as other semiconductor functions, in a single package. High-speed CMOS circuits connected to the top and bottom coils provide the interface between each transformer and its external signals. A high breakdown polyimide layer underneath the gold layer insulates the top transformer coil from the bottom.
Cmos digital isolator plus#
The planar transformers use CMOS metal layers, plus a gold layer that is placed on top of the passivation. ICoupler isolators are magnetic couplers based on chip-scale transformers (Figure 2), as compared with the LEDs and photodiodes used in optocouplers. An isolated dc-to-dc converter can provide power supply isolation, while the iCoupler digital isolator provides the signal isolation. To completely isolate the system, all signal lines and power supplies must be isolated. Referring all devices connected to the bus to a single ground will protect the system against this destructive energy, and isolating the devices will prevent ground loops and electrical surges. Without isolation, this voltage could corrupt the signal or damage the system. When this occurs, the logic-level switching signal expected by the remote system would be superimposed on a high voltage with respect to its local ground. Galvanic isolation allows information flow but prevents current flow.Ĭurrents that are inductively coupled into the long cables found in industrial environments by motors switching on and off, electrostatic discharge (ESD), or nearby lightning strikes can cause rapid changes in ground potential, often as large as hundreds, or thousands, of volts. Without isolation, this current could introduce noise, degrade measurements, or even destroy system components. System grounds that are separated by long cables will not be at the same potential, so ground current will flow between the two systems. Isolation is used to protect against high voltages or currents caused by line surges or ground loops, which can occur in any system that has multiple ground paths.
Transformers, coupling capacitors, optocouplers-and now, iCouplers-are typical means of providing galvanic isolation, which blocks current from flowing between two points, while allowing data to pass unimpeded (Figure 1). Each of the interconnected systems usually has its own power supply, and the systems are often separated by long distances, so galvanic isolation is typically required to break up ground loops, protect the system from high-voltage transients, and reduce signal distortion, as well as for physical safety.
Cmos digital isolator serial#
In applications such as industrial process control, power supply regulation, and point-to-point communications between computers, serial communication buses transmit data over various types of physical networks, such as RS-232, RS-485, and the Controller Area Network (CAN). Digital Isolators protect RS-232, RS-485, and CAN Buses
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