fs6611 Fortune Semiconductor Corporation, fs6611 Datasheet - Page 11

• Manufacturer Part Number: fs6611
• Description: Energy Metering Ic With Impulse Output
• Manufacturer: Fortune Semiconductor Corporation

FS6611
12. Terminology
12.1 Measurement Error
The error associated with the energy measurement made by the FS6611 is defined by the following equation:
Energy Mea
sured
by the
FS6611
-
True
Energy
×
100%
Percentage Error =
True
Energy
12.2 Power Supply Rejection
This quantifies the FS6611 measurement error as a percentage of the reading when the power supplies are
varied.
For the ac PSR measurement, a reading at nominal supplies (5V) is taken. A 200mVrms/100Hz signal is then
introduced onto the supplies and a second reading obtained under the same input signal levels. Any error
introduced is expressed as a percentage of the reading (see Measurement Error definition).
For the dc PSR measurement, a reading at nominal supplies (5V) is taken. The supplies are then varied ±5%
and a second reading is obtained with the same input signal levels. Any error introduced is again expressed as
a percentage of the reading.
12.3 ADC Offset Error
This refers to the dc offset associated with the analog inputs to the ADCs. It means that with the analog inputs
connected to AGND, the ADCs still see a small dc signal (offset). The offset decreases with increasing gain in
Channel V1. This specification is measured at a gain of 1. At a gain of 16, the dc offset is typically less than
1mV.
12.4 Gain Error
The gain error of the FS6611 is defined as the difference between the measured output frequency (minus the
offset) and the ideal output frequency. It is measured with a gain of 1 in Channel V1. The difference is
expressed as a percentage of the ideal frequency. The ideal frequency is obtained from the FS6611 transfer
function (see Transfer Function section).
12.5 Gain Error Match
The gain error match is defined as the gain error (minus the offset) obtained when switching between a gain of
1 and a gain of 8, 16, or 32. It is expressed as a percentage of the output frequency obtained under a gain of 1.
This gives the gain error observed when the gain selection is changed from 1 to 8, 16, or 32
Rev. 1.1
11/20