Datasheet

ADE7953 Data Sheet
Rev. B | Page 36 of 72
PERIOD MEASUREMENT
The ADE7953 provides a period measurement of the voltage
channel. This measurement is provided in the 16-bit, unsigned
period register (Address 0x10E). The period register is updated
once every line period and has a settling time of 30 ms to 40 ms
associated with it before the period measurement is stable.
The period measurement has a resolution of 4.48 µs/LSB
(223 kHz clock), which represents 0.0224% when the line
frequency is 50 Hz and 0.0268% when the line frequency
is 60 Hz.
The value of the period register for a 50 Hz network is approxi-
mately 4460 in decimal (223 kHz/50 Hz) and 3716 in decimal
(223 kHz/60 Hz) for a 60 Hz network. The period register is
stable at ±1 LSB when the line is established and the measure-
ment does not change.
The following equation can be used to compute the line period
and frequency using the period register:
sec
kHz223
1]0:15PERIOD[ +
=
L
T
(36)