HP E42 Model 5328A Theory of Operation, C T I O N I E O R Y O F O P E R a T I O N, Frequency

Model 5328A

Theory of Operation

S E C T I O N I V

T H E O R Y O F O P E R A T I O N

4 - 1 . I N T R O D U C T I O N

4-2. This section contains a description of the operating principles of the counter in reference to an overall block diagram in this section and to individual block and schematic diagrams in Section Vlll.

4-3.OVERALL DESCRIPTION

4-4. The 5328A is a 500 MHz universal frequency counter with the following capabilities.

Frequency — 100 and 500 MHz direct count

Period — 100 ns resolution

Period Average — 10 MHz clock

Time Interval — 100 ns single-shot resolution

Time Interval Average

Ratio — 100 MHz/10 MHz

Check

4 - 5 . BASIC COUNTER OPERATION

4-6. The operation of the frequency counter is best understood by describing how the counter performs a frequency measurement. If n is the number of cycles of a signal that occurs in a time period, t, the average frequency, f, of that signal over the time period, t, is given by

(1)

4-7.Frequency

4-8. The counter measures the frequency, f, by accumulating the number of cycles, n, of the input signal that occurs over the time period, t. The basic counter elements necessary to per- form this measurement are shown in Figure 4-1.

Figure 4-1.Basic Elements of the Frequency Counter

4-1