ES51999
4 3/4 and 5 3/4 A/D AUTO
▪ 40Hz range:
Frequency =
(D2+1)×106
5×(150,950+D1)
100×D0
150950+D1
%
, Duty cycle =
▪ 400Hz range
Frequency =
(D2+1)×106
100×D0
%
,
Duty cycle =
150,950+D1
150,950+D1
100×D0
▪ 4000Hz range
Frequency =
(D2+1)×107
%
,
Duty cycle =
150,950+D1
150,950+D1
▪ 40KHz to 400MHz range (D2 is not needed.)
when C[0] = 0
D0
%
%
Frequency = 10×D1 ,
when C[0] = 1
Frequency = D1 ,
Duty cycle =
200
D0
Duty cycle =
200
ES51999 can measure frequency from 0.5Hz to 409.6MHz. For each range, the
measurable frequencies and resolution are shown in the following table:
Range Measured frequency range Resolutions
40Hz 0.5Hz ~ 40Hz
400Hz 2.5Hz ~ 400Hz
4000Hz 25Hz ~ 4000Hz
40KHz 0 ~ 40.96KHz
400KHz 0 ~ 409.6KHz
4MHz 0 ~ 4.096MHz
40MHz 0 ~ 40.96MHz
400MHz 0 ~ 409.6MHz
0.001Hz
0.01Hz
0.1Hz
1Hz
10Hz
100Hz
1KHz
10KHz
At 40/400/4000Hz, if the input frequency is less than its measurable range, it’s underflow,
and UL will set to ‘H’. At the same ranges, if the input frequency is greater than its
measurable range, it’s overflow, and OL will set to ‘H’. When UL or OL occur, the data
D0, D1, and D2 will not be correct, please ignore them. At 40KHz ~ 400MHz ranges, OL
and UL are always ‘L’, but it’s overflow when the output counts is 40,960.
At different range, the conversion time is different. At 40/400/4000Hz, the conversion
time is according to the input frequency. At other ranges, the conversion time is fixed at
110ms or 1.1s with C[0] = 0 or 1, respectively.
16
07/07/06
CYRUSTEK [ Cyrustek corporation ]
