MCP3909 Microchip Technology, MCP3909 Datasheet - Page 32

• Manufacturer Part Number: MCP3909
• Description: Energy Metering IC with SPI Interface and Active Power Pulse Output
• Manufacturer: Microchip Technology

MCP3909
FIGURE 6-3:
6.3
To achieve meter calibration the MCP3909 waveform
samples are adjusted during the power calculations on
the PIC MCU. In
RS-232 on the PIC microcontroller. This process is
streamlined using calibration software available from
Microchip’s web site.
DS22025A-page 32
N
Meter Calibration
L
Figure
Resistor Divider
Power Supply
Simplified MCU Based Energy Meter.
Circuitry
6-3, this interface is shown via
CH0+
CH0-
CH1+
CH1-
MCP3909
AV
A
GND
DD
,DV
,D
GND
DD
CLKIN
SDO
SCK
SDI
CS
6.4
For analog design tips and PCB layout recommenda-
tions, refer to AN994, "IEC Compliant Active Energy
Meter Design Using The MCP390X” (DS00994). This
application note includes all required energy meter
design information, including the following:
• Meter rating and current sense choices
• Shunt design
• PGA selection
• F2, F1, F0 selection
• Meter calibration
• Anti-aliasing filter design
• Compensation for parasitic shunt inductance
• EMC design
• Power supply design
• No-Load threshold
• Start-up current
• Accuracy Testing Results from MCP390X-based
• EMC Testing Results from MCP390X-based
meter
meter
RC1/CCP2
RC3/SCK
RC5/SDO
RC4/SDI
RA0/ANO
Analog Meter Design Tips
PHA_W:16
ENERGY_W:64
ENERGY_VA_GLSB:16
PHA_I_RMS:16
PHA_V_RMS:16
GND
© 2006 Microchip Technology Inc.
...
RX/RC6
TX/RC7
OSC1
OSC2
kW
kWhr
kVAhr
A
V
LCD
RS-232
To PC or
Calibration
Equipment