JT 2139 TAP Isolator

The JT 2139 is a TAP signal isolation module designed for use in combinational test systems that utilise multiple instrument interfaces. To avoid parasitic capacitance effects and/or unwanted ground loops the JT 2139 can be used to completely galvanically isolate any JTAG Technologies boundary-scan controller from the remainder of the instrumentation system. JT 2139 isolators are a standard component of the JTAG Technologies ‘Symphony’ systems that integrate boundary-scan with In-Circuits Testers etc..


  • Galvanically isolates TAP signals
  • Simple compact design
  • Universally applicable
  • Small design fits easily inside test fixtures
  • One per TAP – only install the number you need per application
  • Basic 5V power supply
  • Full relay isolation per TAP signal

Use in ATEs to fully isolate JTAG/boundary-scan TAP signals from the remainder of the test system. Use of TAP isolation modules avoids the potential for poor functional test measurements due to stray [test] system impedances.

  • Dimensions 36W x 145L x 12H mm
  • Weight 40 grams
  • 4 x 4mm mounting holes
  • Relay separation for all JTAG outputs (TDI, TMS. TCK, TRST) AW, and User signals

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