SA2002EPA Sames, SA2002EPA Datasheet - Page 5

• Manufacturer Part Number: SA2002EPA
• Description: Single Phase Uni-directional Power / Energy Metering IC with Instantaneous Pulse Output
• Manufacturer: Sames

FUNCTIONAL DESCRIPTION
The SA2002E is a CMOS mixed signal Analog/Digital
integrated circuit, which performs power/energy calculations
across a power range of 1000:1, to an overall accuracy of
better than Class 1.
The integrated circuit includes all the required functions for 1-
phase power and energy measurement such as two
oversampling A/D converters for the voltage and current sense
inputs, power calculation and energy integration. Internal
offsets are eliminated through the use of cancellation
procedures. The SA2002E generates pulses, the frequency of
which is proportional to the measured power consumption.
One frequency output (FOUT) is available. The pulse rate
follows the instantaneous power consumption measured.
POWER CALCULATION
In the application circuit (figure 6), the voltage drop across the
shunt will be between 0 and 16mV
resistor of 200µ ) The voltage is converted to a current of
between 0 and 16uA
current sense inputs saturates at an input current of ±25µA
peak.
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SA2002E
N
L
N
L
RSH
GND
R3
Figure 6: Application circuit
GND
R1
R2
RMS
R4
R5
P1
, by means of resistors R1 and R2. The
Supply
GND
DR-01584
R6
U1
RMS
IIN
IIP
IVP
GND
VREF
VDD
VSS
(0 to 80A through a shunt
VSS
SA2002E
FOUT
VDD
VSS
VDD
Pulse output
5/10
For the voltage sensor input, the mains voltage (230VAC) is
divided down through a divider (R3, R4 and P1) to 14V
current into the A/D converter input is set at 14µA
mains voltage, via resistor R5 (1M ). P1 may be varied for
calibration purposes.
In this configuration, with a mains voltage of 230V and a
current of 80A, the output frequency measured on the FOUT
pin is 1360Hz. In this case one pulse on FOUT correspond to
an energy consumption of 18.4kW/1360Hz = 13.53Ws.
ANALOG INPUT CONFIGURATION
The input circuitry of the current and voltage sensor inputs is
illustrated in figure 7. These inputs are protected against
electrostatic discharge through clamping diodes. The
feedback loops from the outputs of the amplifiers A and A
generate virtual shorts on the signal inputs. Exact duplications
of the input currents are generated for the analog signal
processing circuitry.
Figure 7: Internal analog input configuration
DR-01148
CURRENT
SENSOR
INPUTS
VOLTA GE
SENSOR
INPUT
IVP
IIN
IIP
V
V
V DD
V
V
V DD
SS
DD
SS
SS
GND
A
A
I
V
sames
sames
RMS
at nominal
I
RMS
. The
V