ES5120
3 3/4 DIGIT A/D CONVERTER
10.2 Frequency counter theory of Operation :
In addition to serving as an analog to digital converter, the
ES5120 internal counter can also function as a frequency
counter, (Figure 5). In the counter mode,
pulses at the RANGE/FREQ input will be counted and
displayed.
The ES5120 frequency counter derives its timebase from the
colck oscillator. The counter time base is :
4,000,000
Tcounter
=
Fosc
Thus, the counter will operate with a 1 second timebase when
a 40 kHz oscillator is used. The frequency counter accuracy is
determined by the oscillator