MCP3909-I/SS Microchip Technology, MCP3909-I/SS Datasheet - Page 91

• Manufacturer Part Number: MCP3909-I/SS
• Description: IC POWER METERING-1 PHASE 24SSOP
• Manufacturer: Microchip Technology

Specifications of MCP3909-I/SS

• Package / Case: 24-SSOP (0.200", 5.30mm Width)
• Input Impedance: 390 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.85V
• Current - Supply: 2.3mA
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Meter Type: Single Phase
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Supply Voltage Range: 4.5V To 5.5V
• Digital Ic Case Style: SSOP
• No. Of Pins: 24
• Interface Type: Serial, SPI
• Supply Voltage Max: 5.5V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP3909EV-MCU16 - EVALUATION BOARD FOR MCP3909MCP3909RD-3PH1 - REF DESIGN MCP3909 3PH ENGY MTR
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

C.7
C.8
C.9
© 2009 Microchip Technology Inc.
MEASURING SECONDARY PARAMETERS
APPARENT POWER OF EACH PHASE AND TOTAL APPARENT POWER
POWER FACTOR OF EACH PHASE AND TOTAL POWER FACTOR
The methods of measuring parameters such as RMS values of voltage and current,
active power, reactive power and frequency have been discussed in previous sections.
These are primary parameters that need to be calculated from the original data. There
are some other parameters called secondary parameter, such as power factor of each
phase, total reactive power, total active power, total power factor, harmonic
components and cumulative energy. They are obtained indirectly from primary param-
eters.
The measurement of secondary parameters is discussed in this section.
C.7.0.1
For 3-phase 4-wire systems, 3-phase total active power and recative power are the
sum of power of each phase, respectively, which can be expressed as:
EQUATION C-54:
EQUATION C-55:
Apparent power is defined as:
EQUATION C-56:
Power factor is defined as the ratio of active power to apparent power. The definition
can be represented as shown in Equation C-57:
EQUATION C-57:
TOTAL ACTIVE POWER AND TOTAL REACTIVE POWER
Q
P
Power Calculation Theory
PF
=
S
=
=
Q
P
=
A
A
----------------------- -
+
+
Q
P
P
Q
2
2
B
+
P
B
+
+
+
p
Q
2
P
Q
2
C
C
DS51723A-page 91