MCP3909RD-1PH1 Microchip Technology, MCP3909RD-1PH1 Datasheet - Page 23

• Manufacturer Part Number: MCP3909RD-1PH1
• Description: BOARD DES MCP3909 ENERGY METER
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-1PH1

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MCP3909, PIC18F85J90
• Primary Attributes: Single Phase Shunt Energy Meter
• Secondary Attributes: 16 Bit ADC
• Ic Function: Single Phase Energy Measurement IC
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 24
• Interface Type: SPI
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

3.4.4
3.4.5
3.4.6
3.4.7
© 2009 Microchip Technology Inc.
LINE_CYC
LINE_CYC_CNT
PHA_W_RAW
PHA_W
REGISTER 3-4:
Number of line cycles as a power of two. A setting of 0 indicates 2
setting of 1 is 2 line cycles (2
which is 256 line cycles. When written, this register will not take effect until the previous
number of line cycles has been acquired.
REGISTER 3-5:
This register counts from 0 and finishes at 2
LINE_CYC represents the value in the LINE_CYC register.
REGISTER 3-6:
These registers are the raw phase A active power as it represents the sum of each
phase y current A/D value times phase y voltage A/D value results over LINE_CYC line
cycles (each line cycle has 128 results). Each current times voltage multiplication
results in a 32-bit word. There are up to 256 line cycles with each line cycle being
128 results and each result being 32-bit. Thus, a 48-bit register is needed. This is the
register to be read during calibration for calculating the offset and gain values
associated with active phase y power, PHy_W_OFF, PHy_W_GAIN, and
PHy_W_GLSB. These registers are overwritten every line cycle, however if calibration
is enabled, updates will stop once LINE_CYC line cycles have elapsed.
REGISTER 3-7:
These registers are the value for phase A active power. The goal of calibration is to get
these registers values to equal X 0.1 mW/LSB. When displaying the active power for
phase y, simply display the value in these registers with the decimal point one digit in
from the right, in milli-watts. (Note this decimal point location, or LSB resolution of
0.1 mW, is specific for the 5(10)A, 220V rating that this meter is designed for). This
register is overwritten every LINE_CYC line cycles (written only once if calibration is
enabled).
LINE_CYC_CNT
LINE_CYC
Name
PHA_W_RAW
Name
PHA_W
Name
Name
Calculation and Register Description
Bits
16
Bits
LINE_CYC REGISTER
LINE_CYC_CNT REGISTER
PHA_W_RAW REGISTER
PHA_W REGISTER
16
Bits
Bits
48
32
Address
0x00A
1
Address
Address
Address
), a setting of 2 is 4 lines cycles (2
0x00C
0x064
0x076
R/W
Cof
Cof
Cof
Cof
R
R
R
(LINE_CYC)
-1 and then re-starts at 0, where
2
), up to a setting of 8
0
or 1 line cycle. A
DS51884A-page 23