SR620 – Stanford Research Systems Frequency Counters

SR620 – Stanford Research Systems Frequency Counters
1.3GHz (Max. Freq.)

The SR620 Time Interval Counter performs virtually all of the time and frequency measurements required in a laboratory or ATE environment. The instrument single-shot timing resolution and low jitter make it the counter of choice for almost any application.

The SR620 measures time interval, frequency, pulse-width, rise and fall time, period, phase and events. Time intervals are measured with 25 ps rms resolution, making the SR620 one of the highest resolution counters available. Frequency is measured from 0.001 Hz to 1.3 GHz, and a choice of gates ranging from 1 period to 500 seconds is provided. The SR620 delivers up to 11 digits of frequency resolution in one second, making it suitable for measurement applications ranging from short-term phase locked loop jitter, to the long-term drift of atomic clocks. All measurement modes are supported by a wide variety of flexible arming and triggering options.

Charts Unlike conventional counters that only have numeric displays, the SR620 provides live, graphical displays of measurement results. Graphical data is available in three formats: a histogram showing the distribution of values within a set of measurements, a strip chart of mean values from successive measurements, or a strip chart of jitter (standard deviation or Allan variance) values from successive measurements. Up to 250 strip-chart points or histogram bins can be displayed.

25 ps single-shot time resolution
1.3 GHz frequency range
11-digit frequency resolution (1 s) · 0.001° phase resolution
Statistical analysis & Allan variance
Graphical output to X-Y scopes
Hardcopy to printers and plotters
GPIB and RS-232 interfaces
Optional ovenized timebase

Max. Freq.

Freq. Resolution [Digits]

Frequency, Period, Time interval, Event, Rise/Fall Time, Pulse width

More Details
Universal time interval and frequency counter