Typical Sensor Connections; Figure 6. Shunt Sensor Power Meter - Cirrus Logic CDB5480U General Description Manual

1.6

Typical Sensor Connections

The CDB5480U evaluation board provides connections directly to several types of sensors. Flexible
onboard filter networks provide a convenient configuration for three common transducers, including
current shunt, current transformer (CT), or Rogowski coil.
1.6.1 Shunt Power Meter Example
A low-cost current shunt configuration is easily achievable with the CDB5480U evaluation board.
Figure 6 depicts the voltage and current connections for a shunt sensor and its associated filter
configurations.
It is strongly recommended that a low-side (neutral path) current shunt is used — especially in high-
voltage situations. Make sure that all signals are well connected before the power source is turned on.
Extreme care should be taken when connecting high-voltage signals to the CDB5480U evaluation board.
In this configuration it is unnecessary to use a burden resistor. A single anti-alias filter is all that is required
for the current channel. Below the filter corner frequency, the CS5480 inputs will see the same voltage
that is across the shunt. Therefore, the shunt voltage should be kept below the maximum of 50mVp with
I-Channel PGA = 50x. A 10% margin is recommended for the shunt voltage (45mVp).
GND
IIN1+/IIN2+
SHUNT
IIN1-/IIN2-
GND
LINE
GND
DS893DB5
CDB5480U
J1/J12
NO POP
R11/R22
J4

Figure 6. Shunt Sensor Power Meter

J46/J52
J8/J14
R2/R22
100
NO POP
R13/R24
J54/J55
J53/J56
J7/J13
NO POP
R9/R23
100
R1/R21
J44/J51
J6
J45
R5
1K
J11
CDB5480U
R50/R53 1K
IIN1+/IIN2+
0.033UF 0.033UF
C6/C12 C35/C2
0.033UF 0.033UF
C5/C11 C34/C1
IIN1-/IIN2-
R49/R52 1K
VIN+
0.027UF
C4
0.027UF
C9
VIN-
11