AC coupled

AC-coupled SQG handsfree probes block the DC content of the signal, so high-speed data and RF signals up to 6 GHz on a DC-biased line can be measured directly on the PCB. The AC coupling provides up to 50 V DC blocking, preventing the probe from sourcing or sinking DC current at the test point. This helps preserve the circuit bias while allowing small high-frequency signals riding on a DC level to be viewed at full oscilloscope sensitivity. The SQG15-AC, SQG30-AC and SQG60-AC reach 1.5 GHz, 3 GHz and 6 GHz, with usable data rates up to 3 Gbps, 6 Gbps and 12 Gbps at the fundamental. Matched to the data rate, the probes are well suited for DC-biased signals such as HDMI (TMDS), SATA, PCIe, DisplayPort, SuperSpeed USB, PECL, LVPECL and CML. They also help track down noise and decoupling problems on supply and control lines. A low-frequency cutoff below 540 Hz keeps droop negligible, even on long bit runs. These 10:1 low impedance probes have a tip impedance of 500 Ω, or 333 Ω on the SQG60-AC, and connect to oscilloscopes and other instruments with a 50 Ω input, with BNC on the SQG15-AC and SMA on the SQG30-AC and SQG60-AC. A typical tip capacitance of 0.35 pF keeps loading low on fast edges and RF traces. Every probe has its own serial number (SPID), and the measured S-parameters for that individual probe can be downloaded for de-embedding. Place the probe on the test point and release, and the PCBite holder keeps it there without soldering or fixtures.