MCP3909RD-3PH3 Microchip Technology, MCP3909RD-3PH3 Datasheet - Page 33

• 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

6.0
The following application figures represent meter
designs using the MCP3909 device. Some of these
applications ideas are available as fully function meter
reference designs and demo boards. For complete
schematic and for fully function meter designs, visit
Microchip’s web page for demo board and reference
design availability.
.
FIGURE 6-1:
are used on MCP3909 Energy Meter Reference Design.
© 2009 Microchip Technology Inc.
CURRENT
VOLTAGE
MCP3909
ADC
ADC
APPLICATIONS INFORMATION
PIC Microcontroller
Power Calculations from Waveform sampling using PIC MCU. Register names shown
X2
X
F
PHA_V_RMS_OFF:16
X2
PHA_DELAY:8
S
PHA_I_RMS_OFF:16
PHA_W_OFF:32
S
S
6.1
Figure 6-1
waveform data based on a PIC MCU and MCP3909
device. The PIC MCU accomplishes the following
energy meter calculation outputs per phase, per line
cycle:
Output registers for the power quantities and
calibration registers for phase, offset, gain, and LSB
adjustment are available through a serial interface to
the PIC microcontroller. See Microchip’s web page for
firmware solution and demo board.
The example signal flow here shows 4 output power
quantities and 6 calibration registers. For a 60 Hz
design that is using 128 samples per line cycle for the
power calculation the MCP3909 would have a new
data
communication to gather 16-bits x 2 channels at
10 MHz is approximately 3.2 µs, leaving ~125 µs for
the power calculations before the next sample is ready.
PHA_W_GAIN:16
- RMS Current
- RMS Voltage
- Active Power
- Apparent Power
ready
X
Performing RMS, Apparent Power,
and Active Power using MCP3909
Waveform data
represents
pulse
X
PHA_VA_GAIN:16
every
power
MCP3909
X
130 µs.
calculations
DS22025B-page 33
RMS Current
Apparent Power
Active Power
RMS Voltage
The
from
SPI