Datasheet

46
Transmission line probes are a special type of passive probe designed for use at
very high frequencies. They replace the high impedance probe cable found in a
traditional passive probe with a precision transmission line, with a characteristic
impedance that matches the oscilloscope input (50 Ω). This greatly reduces
the input capacitance to a fraction of a picofarad, minimizing the loading of
high frequency signals. A matching network at the tip increases the DC input
resistance. While they have lower DC input resistance than a traditional passive
probe (usually 500 Ω to 5 kΩ), the input impedance of these probes remains
nearly constant over their entire frequency range. A traditional ÷10 passive probe
will have a 10 MΩ input impedance at DC, however this impedance drops rapidly
with frequency, passing below the input impedance of a transmission line probe at
less than 100 MHz.
In some applications, transmission line probes offer advantages over active
probes. In addition to being less expensive, their passive design is more robust
to over voltage and ESD exposure. They are useful in applications producing fast
rising, narrow pulses with amplitudes which exceed the dynamic range of active
probes. They also tend to have less parasitic effects on frequency response.
TRANSMISSION LINE PROBES
Teledyne LeCroy
Transmission Line Probe
Model Number:
PP066