78m6618-imr/f/p Maxim Integrated Products, Inc., 78m6618-imr/f/p Datasheet - Page 8

• Manufacturer Part Number: 78m6618-imr/f/p
• Description: Octal Power And Energy Measurement Ic
• Manufacturer: Maxim Integrated Products, Inc.

78M6618 Data Sheet
See the 78M6618 Programmer’s Reference Manual for more information regarding the programmability
of the 78M6618 AFE.
1.4.1 Analog Current and Voltage Inputs
Pins IA, IB, IC, ID, IE, IF, IG, IH, VA, VB are analog inputs the AFE that provide support for measuring
current and voltage in a variety of ways. Various current sensor technologies are supported including
Current Transformers (CT), Resistive Shunts and Rogowski coils.
1.5
The CE, a dedicated 32-bit digital signal processor, performs the precision computations necessary to
accurately measure energy. Typically CE calculations and processes include:
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See the 78M6618 Programmer’s Reference Manual for more information on interfacing to and
configuration of the 78M6618 CE.
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Scaling of the processed samples based on calibration coefficients.
Frequency-insensitive delay cancellation on all channels
90° phase shifter (for narrowband VAR calculations).
Monitoring of the input signal frequency (for frequency and phase information).
Monitoring of the input signal amplitude (for sag detection).
Multiplication of each voltage and current sample to obtain the energy per sample.
RTM(Real Time Monitor) for debug purposes
Pulse Generators used to output CE status indicators (e.g. SAG) directly to designated DIO pins.
Due to the custom nature and complexity of the CE, generally, pre-compiled CE code is provided by
Teridian as a part of the available reference firmware and is not modified by the user. Please contact
Teridian support for more information regarding CE code.
Digital Computation Engine (CE)
VA
VB
IC
IG
IA
ID
IH
IB
IE
IF
TEMP
VBAT
CTRL
MUX
MUX
MUX
Figure 2: AFE Block Diagram
CROSS
CK32
VBIAS
VREF
VREF
FIR_DONE
FIR_START
V3P3A
VBIAS
+
VREF
-
CONVERTER
4.9152 MHz
∆Σ ADC
FIR
DS_6618_005
Rev. 1.3