Sondes Oscilloscopes LeCroy

Current Probes Current Probes measure the current passing through a wire; current probes do not use the "traditional" probing style of placing a tip onto a test point. Rather, a wire is placed inside of the "jaw" of the probe, which then allows the probe to measure the current (in Amps).
 
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Active Probes There are two different types of active probes: "single-ended" and "differential."

Single Ended: A single-ended active probe is associated with measuring voltages at high frequencies. Measurement with an active probe requires a test point and a ground point. The ground (also called earth) acts as a zero reference for the test point measurement.
 

Differential Probes Differential active probes are like two probes in one. Instead of measuring a test point in relation to a ground point (like single-ended active probes), differential probes measure the difference in voltage of a test point in relation to another test point.

Differential Probes <1 GHz

Differential Probes >10 GHz

Differential Probes WaveLink Series 

Passive Probes Passive probes measure voltages at lower frequencies (<400 MHz). They have higher input capacitance (input C) and do not need power to operate (unlike active probes). At higher frequencies, higher input capacitance loads the test circuit, attenuating the signal. This is why active probes are used in high frequency applications. Passive probes also measure voltage in reference to ground.
 
High-Voltage Probes These are active single ended probes that are designed to measure high voltages (safely). They measure the voltage in reference to ground.
 
Transmission Line Probes  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 (50W). 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 W to 5 kW), the input impedance of these probes remains nearly constant over their entire frequency range. A traditional ¸10 passive probe will have a 10 MW 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. A high BW transmission line probe driving a sampling oscilloscope can be used as a "golden standard" in situations when the response of an active probe measurement is questioned.

   
   
   
   
 
   
 
   
   
   
   
   
   
 
   
 
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
 
   
   
   
   
   
 
   
   
 
   
   
   
   
   
   
 
   
   
   
   
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