PM9103AP

sames

4/10

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 625µ

Ω). The current

input stage of the module, saturates at input currents greater than 18µA

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).