CS5461A datasheet(14/41 Pages) CIRRUS

14 / 41 page

CS5461A

DS661F1

The apparent power is the combination of the active

power and reactive power, without reference to an im-

pedance phase angle, and is calculated by the

CS5461A using the following formula:

The apparent power is registered once every computa-

tion cycle.

4.4 Linearity Performance

The linearity of the VRMS, IRMS, and active power mea-

surements (before calibration) will be within ±0.1% of

reading over the ranges specified, with respect to the in-

put voltage levels required to cause full-scale readings

in the IRMS and VRMS registers. Refer to Linearity Per-

formance Specifications on page 7.

Until the CS5461A is calibrated, the accuracy of the

CS5461A (with respect to a reference line-voltage and

line-current level on the power mains) is not guaranteed

to within ±0.1%. See Section 7. System Calibration on

page 33. The accuracy of the internal calculations can

often be improved by selecting a value for the Cycle

Count Register that will cause the time duration of one

computation cycle to be equal to (or very close to) a

whole-number of power-line cycles (and N must be

greater than or equal to 4000).

SVRMS IRMS

CS5461A Datasheet(PDF) 14 Page - Cirrus Logic