PM9103AP
FUNCTIONAL DESCRIPTION
1. Power Calculation
In the Application Circuit (see Figure 2), the output current from the current sensor
will be between 0 and 16µA (0 to 80A through a shunt resistor of 625µΩ). The current
input stage of the module, saturates at input currents greater than 18µA
RMS
. T h e
mains voltage (Voltage + 15% - 20%) is used to supply the circuitry with power and
to perform the power calculation, together with the current information from the
current sensor (shunt resistor).
The SA9103CP, SA9103EP and SA9603C integrated circuits may be adjusted to
accommodate any voltage or current values. The method for calculating external
component values is described in paragraph 6 (Circuit Description).
SAMES offers two evaluation module options, namely 230V/80A and 115V/80A.
The calculated power is integrated into a 22 bit integrator, which is accessable via
a serial interface having a RS232 protocol. The power calculation takes the power
factor into account.
2. Electrostatic Discharge (ESD) Protection
The device's inputs/outputs are protected against ESD according to the Mil-Std
883C, method 3015. The modules resistance to transients will be dependant upon
the protection components used.
3. Power Consumption
The overall power consumption rating for this power metering application (Figure 2),
is under 500mW, excluding the current sensor, when the supply is taken directly from
the mains.
4. Isolation
The serial interface is isolated from the module which is at mains potential, via two
opto-couplers. (In the event of the use of a current transformer for current sensing,
the opto-couplers would not be required.)
5. Serial Interface
Reading and resetting of the on-chip integrators may be performed using a Personel
Computer (PC). A standard serial cable should be used to connect SK1 to the PC.
The computers port settings are as follows:
19 200 Baud
1 Start bit
1 Stop bit
No parity bits
The Serial Interface allows for the following operations:
Read Integrator:
The device transmits the current integrator status to the controller,
after the current measurement cycle has been completed (8 mains periods maximum).
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SAMES [ SAMES ]
