User`s guide

53220A/53230A User’s Guide 159
Triggering and Gating 5
53220A/53230A data sheet, extends the resolution beyond what is achieved
with the basic reciprocal measurement technique. Resolution enhancement
applies to the counter’s AUTO or CONTinuous mode with gate times >
10 msec.
Table 5-2 shows the digits of resolution achieved with the 53230A and 53220A
for a given gate time. The table also includes formulas for estimating digits as a
function of gate time or expected values, and gate times as a function of digits.
Table 5-2. Resolution and Gate Time.
Gate Time
(53230A)
(T
ss
= 20 ps)
Resolution
(Digits)
Auto/Continuous
Resolution
(Digits)
Reciprocal
Calculating Digits and Gate
Time (Reciprocal Mode)
1 usec 4.7 4.7
Digits as a function of gate time:
Digits = Log
10
(gate time/T
ss
)
Digits as a function of expected
value (CONFigure, MEASure)
Digits = Log
10
(expected value)
- Log
10
(resolution)
Gate time as a function of digits:
gate time = (10^digits) * T
ss
10 usec 5.7 5.7
100 usec 6.7 6.7
1 msec 7.7 7.7
10 msec up to 10* 8.7
100 msec up to 11* 9.7
1 sec up to 12* 10.7
10 sec up to 13* 11.7
100 sec up to 14* 12.7
1000 sec up to 15* 13.7 usec
Gate Time
(53220A)
(T
ss
= 100 ps)
Resolution
(Digits)
Auto
Resolution
(Digits)
Reciprocal
100 usec 6 6
1 msec 7 7
10 msec up to 10* 8
100 msec up to 11* 9
1 sec up to 12* 10
10 sec up to 13* 11
100 sec up to 14* 12
1000 sec up to 15* 13
* Resolution Enhanced