Interference-free Boundary Scan Applications

“The topic of interference immunity and potential isolation play a role for mixed-signal designs with integrated power electronics. Moreover, they are requested from the start in several safety-critical applications in the areas of space and avionics as well as medical technology”, says Bettina Richter, Marketing Manager with GOEPEL electronic. “The TAP-Isolator is a standard product addressing these issues for conventional single-ended interconnections. In combination with the already available solutions for potential isolation for differential signal transmissions we are now able to cover every application scenario.”



The TAP-Isolator is an small stand-alone box that can be used as add-on hardware in each scan path. It separates the transceiver’s primary TAP interface from the target’s secondary TAP interface, and is easily upgradable at any time.



The potential isolation eliminates mutual interference between TAP transceiver and target. That means an increase in the functional safety of Boundary Scan applications such as interconnection test, PLD programming or Flash programming.



The TAP-Isolator can be operated on the secondary side with fixed or variable output voltage between 1.8 V and 4.5 V, and maximum transmission frequency of 70 MHz. It supports all standard TAP signals (TCK, TMS, TDI, TDO) as well as the optional /TRST.



The isolation hardware’s possible runtime delays when used with modern Boundary Scan systems such as SCANFLEX can be individually compensated per TAP by the integrated ADYCS technology. Additionally, the TAP-Isolator can be run with all JTAG controllers from GOEPEL electronic, e.g. PicoTAP and SCANBOOSTER, as well as other vendors.



The TAP-Isolator will be ready for shipping in September 2012.