The ADE7769 specifications surpass the accuracy require-
ments of the IEC62053-21 standard. The AN-679 Application
Note can be used as a basis for a description of an IEC61036
(equivalent to IEC62053-21) low cost, watt-hour meter
reference design.
The only analog circuitry used in the ADE7769 is in the Σ-Δ
ADCs and reference circuit. All other signal processing, such as
multiplication and filtering, is carried out in the digital domain.
This approach provides superior stability and accuracy over
time and extreme environmental conditions.?
The ADE7769 supplies average real power information on the
low frequency outputs, F1 and F2. These outputs can be used to
directly drive an electromechanical counter or interface with an
MCU. The high frequency CF logic output, ideal for calibration
purposes, provides instantaneous real power information.
The ADE7769 includes a power supply monitoring circuit on
the VDD supply pin. The ADE7769 remains inactive until the
supply voltage on VDD reaches approximately 4 V. If the supply
falls below 4 V, the ADE7769 also remains inactive and the F1,
F2, and CF outputs are in their nonactive modes.
Internal phase matching circuitry ensures that the voltage and
current channels are phase matched, while the HPF in the
current channel eliminates dc offsets. An internal no-load
threshold ensures that the ADE7769 does not exhibit creep
when no load is present. During a no-load condition, the CF
pin stays logic high.
The ADE7769 has a 16-lead, narrow body SOIC package.