PM9105AF
For rated conditions, the signals into the current and voltage sensor inputs are set
as follows:
Current sensor input currents:
Voltage sensor input currents:
16µ A
RMS
14µ A
RMS
Under these conditions, the device generates a pulse rate of 1,16kHz at output
FOUT1.
The output frequency at FOUT2 is FOUT1/4. At FOUT3 the output frequency is
FOUT1/290.
2.
Electrostatic Discharge (ESD) Protection
The device's inputs/outputs are protected against ESD according to Mil-Std 883C,
method 3015. The modules resistance to transients will be dependant upon the
protection components used.
Power Consumption
The overall power consumption rating for this power metering application (Figure 2),
is under 500mW, excluding the current sensors.
Isolation
The reference for the unit is connected to neutral.
Circuit Description
The module is supplied from an external 5V DC supply.
The Application Circuit (figure 2), details the components required for a three phase
power metering module. Terminated current transformers are used as current
sensors.
The most important external components are:
C
7
, C
9
, C
10
and C
11
are the outer loop capacitors for the integrated oversampling
A/D converters. The typical value of C
7
is 2.2nF and the value of C
9
, C
10
and C
11
is
560pF.
The actual values determine the signal to noise and stability performance. The
tolerances should be within ± 10%.
C
4
, C
5
, C
6
and C
8
are the inner loop capacitors for the integrated oversampling
A/D converters. The typical value of C
4
, C
5
, C
6
and C
8
is 3.3nF. Values smaller than
0.5nF and larger than 5nF should be avoided.
Terminated current sensors (current transformers) are connected to the current
sensor inputs of the SA9105 through current setting resistors (R
8
..R
13
).
The resistor values should be selected for an input current of 16µA into the SA9105
at the rated line current.
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