Driver Board for Boundary Scan TCK lines

About the Driver Board for Boundary Scan TCK lines

A high percentage of boards that are tested using in-circuit testers (ICT), have boundary scan devices. These components may have individual JTAG port access or be connected in a chain, sharing common TCK and TMS signals. Since communication with the testing device(s) is done on a serial basis, clean signals and good waveforms are critical.

It is especially difficult to achieve stable conditions in an ICT environment, where noise level is significant and cross talk between numerous wires housed in the test fixture is high. These factors may cause false test failures and difficulties while debugging, or running the test program on different testers. Long chains are particularly sensitive to noise, and special tests like VIT and VCCT are impossible to apply without a "good" clock.

The use of passive components, such as capacitors or filters, to mitigate these unwanted effects does not always provide satisfactory results.

WHY USE

The Driver Board actively filters and restores signals thereby eliminating the instability caused by noise, cross talk and bad tester drivers. Consequently, test debugging time is significantly reduced and the implementation of VIT and VCCT tests is facilitated.

OVERVIEW

• Filters noise, which is higher than the frequency of the tester highest digital stim.
• Corrects and conditions bad waveform
• Has bypass capability to perform test for passive components on the same net
• Small form factor allows it to be mounted as close as possible to source of the noise
• Can be easily installed in the test fixture
• Versatile – can be used for a variety of applications

The Driver Board is manufactured in 2 and 4 channel versions. The bottom side of the board is flat, as a result, it can be mounted in the fixture without the need for screws.