MCP3909RD-3PH3 Microchip Technology, MCP3909RD-3PH3 Datasheet - Page 62

• Manufacturer Part Number: MCP3909RD-3PH3
• Description: REF DESIGN FOR MCP3909 W/18F2520
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH3

• Main Purpose: Power Management, Energy/Power Meter
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MCP3909 3-Phase Energy Meter Reference Design
DS51643B-page 58
TABLE 6-1:
6.4.1
The location of the decimal point, i.e the resolution of the power quantities, is
determined by the values that are entered in the meter design section of this screen.
When the meter is calibrated using the calibration steps automated with this software,
the proper GLSB correction factor is calculated to ensure the least significant bit
represents the least significant digit for a given quantity. For example, if the
PHA_I_RMS register, which represents the RMS current for Phase A, contains the
decimal value 4523 and the ILSB has been defined to be 0.01 based on the meter
design entry, this value represents exactly 45.23 Amperes.
Another example for active power as shown in Figure 6-2, the PHA_W register con-
tains the value 1014498. For this meter design example the power resolution was
defined to be 0.1 mW. Therefore this register represents exactly 101.4498 Watts.
Apparent Power, Phase B
Apparent Power, Phase C
RMS Current Phase A
RMS Current Phase B
RMS Current Phase C
RMS Voltage Phase A
RMS Voltage Phase B
RMS Voltage Phase C
Note 1:
Meter Reading
At the time of this software and document release, reactive power and reactive
energy is not supported. Contact Microchip for updated software and firmware that
will be available for these power quantities.
Decimal Point Location
REGISTERS BEING READ FOR THE METER READING (NOTE 1)
PHA_V_RMS
PHB_V_RMS
PHC_V_RMS
PHA_I_RMS
PHB_I_RMS
PHC_I_RMS
Register
PHC_VA
PHB_VA
© 2008 Microchip Technology Inc.
266.2323 VA
208.11 VA
Example
10.23 A
220.1 V
222.4 V
220.9 V
0.45 A
0.33 A