ADE7878ACPZ Analog Devices Inc, ADE7878ACPZ Datasheet - Page 20

• Manufacturer Part Number: ADE7878ACPZ
• Description: IC ENERGY METERING 3PH 40LFCSP
• Manufacturer: Analog Devices Inc

Specifications of ADE7878ACPZ

• Input Impedance: 400 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.4V
• Current - Supply: 22mA
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-WFQFN, CSP Exposed Pad
• Meter Type: 3 Phase
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LFCSP
• No. Of Pins: 40
• Msl: MSL 1 - Unlimited
• Peak Reflow Compatible (260 C): Yes
• Supply Voltage Min: 3V
• Rohs Compliant: Yes
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADE7854/ADE7858/ADE7868/ADE7878
TERMINOLOGY
Measurement Error
The error associated with the energy measurement made by the
ADE7854/ADE7858/ADE7868/ADE7878 is defined by
Phase Error Between Channels
The high-pass filter (HPF) and digital integrator introduce a
slight phase mismatch between the current and the voltage
channel. The all digital design ensures that the phase matching
between the current channels and voltage channels in all three
phases is within ±0.1° over a range of 45 Hz to 65 Hz and ±0.2°
over a range of 40 Hz to 1 kHz. This internal phase mismatch
can be combined with the external phase error (from current
sensor or component tolerance) and calibrated with the phase
calibration registers.
Power Supply Rejection (PSR)
This quantifies the ADE7878 measurement error as a percen-
tage of reading when the power supplies are varied. For the ac
PSR measurement, a reading at nominal supplies (3.3 V) is
taken. A second reading is obtained with the same input signal
levels when an ac signal (120 mV rms at 100 Hz) is introduced
onto the supplies. Any error introduced by this ac signal is
expressed as a percentage of reading—see the Measurement
Error definition.
For the dc PSR measurement, a reading at nominal supplies
(3.3 V) is taken. A second reading is obtained with the same
input signal levels when the power supplies are varied ±10%.
Any error introduced is expressed as a percentage of the
reading.
Measurement Error =
Energy
Registered
True
by
ADE
Energy
7878
−
True
Energy
×
100
%
Rev. D | Page 20 of 96
(1)
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 dc analog input signal. The magni-
tude of the offset depends on the gain and input range selection
(see the Typical Performance Characteristics section). However,
the HPF removes the offset from the current and voltage channels
and the power calculation remains unaffected by this offset.
Gain Error
The gain error in the ADCs of the ADE7858/ADE7868/ADE7878/
ADE7854 is defined as the difference between the measured
ADC output code (minus the offset) and the ideal output code
(see the Current Channel ADC section and the Voltage Channel
ADC section). The difference is expressed as a percentage of the
ideal code.
CF Jitter
The period of pulses at one of the CF1, CF2, or CF3 pins is
continuously measured. The maximum, minimum, and average
values of four consecutive pulses are computed as follows:
The CF jitter is then computed as
Maximum = max(Period
Minimum = min(Period
Average =
CF
JITTER
=
Maximum
Period
0
Average
+
Period
−
Minimum
0
0
, Period
, Period
1
+
4
Period
1
1
, Period
, Period
×
100
2
+
%
2
, Period
Period
2
, Period
3
3
)
3
)
(2)