SA9602E
The output on pin FOUT is a pulse density signal representing the instantaneous power/
energy measurement. The minimum timing characteristics are shown in the following
diagram.
71us
71us min.
DR-01151
TYPICAL APPLICATIONS
In the Application Circuits (Figures 1 and 2), the components required for power metering
applications, are shown.
In Figure 1 a shunt resistor is used for current sensing. In this application, the circuitry
requires a +2.5V, 0V, -2.5V DC supply.
In the case of Figure 2, when using a current transformer for current sensing, a +5V, 0V
DC supply is sufficient.
The most important external components for the SA9602E integrated circuit are:
R
2
, R
1
and RSH are the resistors defining the current level into the current sense input. The
values should be selected for an input current of 16µA
RMS
into the SA9602E at maximum
line current.
Values for RSH of less than 200µΩ should be avoided.
R
1
= R
2
= (I
L
/16µA
RMS
) * R
SH
/2
Where I
L
= Line current
RSH
= Shunt resistor/termination resistor
R
3
, R
6
and R
4
set the current for the voltage sense input. The values should be selected
so that the input current into the voltage sense input (virtual ground) is set to 14µA
RMS
.
R
7
defines all on-chip bias and reference currents. With R
7
= 24kΩ, optimum conditions
are set. R
7
may be varied within ±10% for calibration purposes. Any change to R
7
will affect
the output quadratically (i.e.: R
7
= +5%, f
P
= +10%).
The formula for calculating the output frequency is given below:
FOSC
I
I
.I
V
f = 11.16 * FOUTX *
*
2
3.58MHz
I
R
Where FOUTX
= Normal rated frequency (4Hz or 1160Hz)
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