Opto-isolators offer an inexpensive method of signal isolation, but have some significant limitations, as they
tend to degrade with age. This degradation is accelerated by ambient temperature: The longer the devices
see a high temperature and the higher the temperature, the faster the degradation of the opto-isolator.
The power consumption of IsoLoop devices is independent of the mark space ratio and solely dependent on frequency. This makes for a lower power consumption than opto isolators, whose power consumption is
heavily dependent on on-state and frequency.
A new range of Isoloop magnetic isolators now allows the designer to circumvent these possible future
issues. IsoLoop digital magnetic isolators work by differentiating the incoming pulse and using the resultant edge to power a coil which creates a magnetic field for a short period of time. This pulse then changes the state of a 1-bit magnetic memory which then is buffered to provide the output. The isolation is achieved between the coil and the 1-bit non-volatile magnetic memory.
The non-volatile nature of the magnetic memory used to lead to an undefined state at start up. The new
IL500 series of IsoLoop isolators has a patented, controllable refresh clock to ensure I/O synchronisation
within 9 μsec while some devices in the series use an external synchronisation clock input.
All IL500 series isolator channels operate at 2Mbps over the full temperature and supply voltage ranges.
Maximum propagation delay is 25 nsec, and pulse-width distortion is 10 nsec. All models feature very low EMC emissions.
The series is available in 1, 2, 3, and 4 channel models; the 1 and 2 channel models are available in either
SOIC packages or 8 pin MSOPs. The 3 and 4 channel models are available in 16-pin SOIC packages. The isolators operate over a supply-voltage range of 3 to 5.5V and temperature range of -40 to +85°C. Typical transient immunity is 30 kV/μsec. The parts are UL 1577-approved, and IEC 61010-2001 approval is
pending.