ADE7758ARW Analog Devices Inc, ADE7758ARW Datasheet - Page 42

• Manufacturer Part Number: ADE7758ARW
• Description: IC ENERGY METERING 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of ADE7758ARW

• Rohs Status: RoHS non-compliant
• Input Impedance: 380 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 8mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.300", 7.50mm Width)
• Meter Type: 3 Phase
• Lead Free Status / RoHS Status: Not Compliant

ADE7758
The interrupt request output IRQ stays low until the interrupt
routine reads the reset status register (see the
CALIBRATION
A reference meter or an accurate source is required to calibrate
the ADE7758 energy meter. When using a reference meter, the
ADE7758 calibration output frequencies APCF and VARCF are
adjusted to match the frequency output of the reference meter
under the same load conditions. Each phase must be calibrated
separately in this case. When using an accurate source for
calibration, one can take advantage of the line cycle accumulation
mode and calibrate the three phases simultaneously.
There are two objectives in calibrating the meter: to establish
the correct impulses/kW-hr constant on the pulse output and to
obtain a constant that relates the LSBs in the energy and rms
registers to Watt/VA/VAR hours, amps, or volts. Additionally,
calibration compensates for part-to-part variation in the meter
design as well as phase shifts and offsets due to the current
sensor and/or input networks.
Interrupts
section).
Rev. D | Page 42 of 72
Calibration Using Pulse Output
The ADE7758 provides a pulsed output proportional to the
active power accumulated by all three phases, called APCF.
Additionally, the VARCF output is proportional to either the
reactive energy or apparent energy accumulated by all three
phases. The following section describes how to calibrate the
gain, offset, and phase angle using the pulsed output information.
The equations are based on the pulse output from the ADE7758
(APCF or VARCF) and the pulse output of the reference meter
or CF
Figure 76 shows a flowchart of how to calibrate the ADE7758
using the pulse output. Because the pulse outputs are
proportional to the total energy in all three phases, each phase
must be calibrated individually. Writing to the registers is fast to
reconfigure the part for calibrating a different phase; therefore,
Figure 76 shows a method that calibrates all phases at a given
test condition before changing the test condition.
EXPECTED
.