[EMAIL PROTECTED] wrote: > In a message dated 4/29/2007 04:13:30 Pacific Daylight Time, > [EMAIL PROTECTED] writes: > > >Indeed. Three-four transistors and a handfull of caps and > resistors. The > >Z3801A uses the 10 MHz clock and thus require a x1000 > interpolation, which is > >easy enought to acheive. Look at the HP5335A service manual for > further > >details. What you do is that you stretch the error-pulse (1-2 > cycles) by > >charging a cap with one current and discharging it with another, > the output is > >then run into a comparator for the sake of gain. This stretched > pulse is then > >measured with the coarse clock and voila! > > Hi Magnus, > > I respectfully disagree, if it was that easy to get 100ps _accuracy_ > and resolution, then the 53132A would have it and not 150ps I would > think. > > > bye, > Said Said
Try studying a little history, its been possible to achieve 25 picosecond accuracy and resolution for over 30 years. Such resolution is routine in Nuclear instrumentation. State of the art nuclear instrumentation strives for subpicosecond resolution and accuracy. The reason that the 53132A doesn't have resolution and accuracy better resolution than 150ps, is that a design choice was made to implement it all (counters plus interpolators) in a CMOS chip using the delay of a CMOS inverter to set the resolution. This reduces the cost and complexity significantly and allows faster cycling of the interpolator facilitating continuous operation with zero deadtime between measurements. The drawback is reduced resolution and the requirement for frequent calibration or the use of a delay lock loop to correct the for the CMOS inverter delay tempco. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts