PM4100APD
ssaammeess
Module Calibration
The output frequency can be adjusted and calibrated by means
of the variable resistor P1 connected in the voltage divider as
showninfigure2.
It is advisable to keep the ground plane surrounding the device
clear of noise that may influence the sensing signals.
The module is protected from high transients on the main
voltage input by means of a Metal Oxide Varistor. These MOVs
will clamp any high transients with a sufficiently long rise time to
neutral, hence protecting the PCB. When designing a meter, a
MOV of type S20 should be used, as the S10 type titled here will
notwithstandhighsurgetests.
PCBDesignConsiderations
There are numerous PCB design aspects to consider when
designing a power/energy meter, but only a few crucial aspects
will be discussed here.
The sense resistors on the current input, R2 and R3 must be
located as close to the SAMES device input pins as possible.
This also holds true for the 1MW resistor (R8), and the biasing
resistor R4. Also note that the supply bypass capacitors C2, C3
and C4 (insert C5 and C6 for the SA2002P) must be positioned
as close as possible to the supply pins of the device, and
connectedtoasolidgroundplane.
Figure 9: Jumper positions
7/14
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