ADE7761A Datasheet, PDF (7/24 Pages) Analog Devices – Energy Metering IC with On-Chip Fault and Missing Neutral Detection

ADE7761A
Pin No.
15
16
17
18
19, 20
Mnemonic
FAULT
REVP
DGND
CF
F2, F1
Description
This logic output goes active high when a fault or missing neutral condition occurs. A fault is defined as a
condition under which the signals on V1A and V1B differ by more than 6.25%. A missing neutral condition is
defined when the chip is powered up with no voltage at the input. The logic output is reset to zero when a fault
or missing neutral condition is no longer detected. See the Fault Detection section and the Missing Neutral Mode
section.
This logic output goes logic high when negative power is detected, that is, when the phase angle between the
voltage and current signals is greater than 90°. This output is not latched and is reset when positive power is once
again detected. The output goes high or low at the same time as a pulse is issued on CF.
This pin provides the ground reference for the digital circuitry in the ADE7761A, that is, multiplier, filters, and
digital-to-frequency converters. This pin should be tied to the digital ground plane of the PCB. The digital ground
plane is the ground reference for all digital circuitry, such as counters (mechanical and digital), MCUs, and
indicator LEDs. For good noise suppression, the analog ground plane should be connected only to the digital
ground plane at the DGND pin.
Calibration Frequency Logic Output. The CF logic output, active high, gives instantaneous active power
information. This output is used for operational and calibration purposes. See the Digital-to-Frequency Conversion
section.
Low Frequency Logic Outputs. F1 and F2 supply average active power information. The logic outputs can be
used to directly drive electromechanical counters and 2-phase stepper motors.
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