MCP3919 Datasheet, PDF (57/88 Pages) Microchip Technology – 3V Three-Channel Analog Front End

MCP3919
8.0 BASIC APPLICATION
RECOMMENDATIONS
8.1 Typical Application Examples
The application schematic referenced in Figure 8-1 can
be used as a starting point for MCP3919
applications.The most common solution is to use one
channel for voltage measurement and the rest of the
channels for current measurement. Since all current
lines are at the same potential, shunts can be used as
current sensors, even if they do not provide any
galvanic isolation.
Since all channels are identical in the MCP3919, any
channel can be chosen as the voltage channel (prefer-
ably CH0 or CH2 since they are on the edges and can
lead to a cleaner layout).
CH0+
GND
CH0-
J20
1x3
R18
0603
1k 1%
GNDA
GNDA
GNDA
R65
0603
1k 1%
CH1-
GND
CH1+
J22
1x3
R69
0603
1k 1%
GNDA
GNDA
GNDA
R71
0603
1k 1%
CH2+
GND
CH2-
J24
1x3
R75
0603
1k 1%
GNDA
GNDA
GNDA
R77
0603
1k 1%
R16 0603
1k 1%
J7
GNDA
2x3
R67 0603
1k 1%
R68 0603
1k 1%
J21
GNDA
2x3
R73 0603
1k 1%
R74 0603
1k 1%
J23
GNDA
2x3
R79 0603
1k 1%
3.3A
3.3D
R64
1k 1%
0603
R66
1k 1%
0603
R70
1k 1%
0603
R72
1k 1%
0603
R76
1k 1%
0603
R78
1k 1%
0603
C47
0.1uF
0603
GNDA
C50
0.1uF
0603
R9
10R
ADC
R7
10R
0603
0603
C4 0603
0.1uF
C3 0603
0.1uF
GNDA GND
1 _AVDD
DVDD ²⁸
C51
0.1uF
0603
GNDA
C52
0.1uF
0603
C53
0.1uF
0603
GNDA
C54
0.1uF
0603
16 _AGND
GNDA
CH0+
CH0-
2
3
CH0+
CH0-
CH1-
CH1+
4
5
CH1-
CH1+
CH2+
CH2-
6
7
CH2+
CH2-
8
9
NC
NC
14
15
REFIN+
REFIN-
GNDA
C5
0.1uF
0603
U5
MCP3919
GNDA
DGND
DGND
20
17
GND
RESET
SDI
SDO
SCK
CS
DR
27
26
25
24
23
18
R5
100R
R8
10R
R12
10R
OSC2
OSC1/CLKI
22
21
NC
NC
NC
NC
NC
19
13
12
11
10
0603
R6 0603
0603 10R
R10 0603
0603 10R
R14 0603
10R
RA5/3912_RESET
RG8/3912_SDI
RG7/3912_SDO
RG6/3912_SCK
RG9/3912_CS
RA14/3912_DR
ADC CLOCK SELECT
J3
ECCP3
XTAL
XTAL
2x3
R17
10R
0603 _{RD3/3912_CLKIN}
C6 0603
18pF
GND
R20
1M 1%
0603
X1
10MHz
C7 0603
18pF
GND
FIGURE 8-1:
MCP3919 Application Example Schematic.
For polyphase metering applications, such as three-
phase meters, it is recommended to use a current
sensor that provides galvanic isolations: current
transformers, Rogowski coils, Hall sensors, etc.
 2014 Microchip Technology Inc.
DS20005347A-page 57