SA2007P Datasheet, PDF (5/12 Pages) Sames – Programmable Single Phase Energy Metering IC with Tamper Detection

SA2007P
sames
INPUT SIGNALS
VREF
A bias resistor of 24kW set optimum bias and reference
conditions on chip. Calibration of the SA2007P should be done
as described in the Device Configuration section.
Serial Data (SDA)
The SDA pin connects directly to the SDA pin of an external
EEPROM. The pin is used to transfer data between the
EEPROM to the SA2007P. An external pull up resistor in not
needed.
Serial Clock (SCL)
The SCL pin connects directly to the SCL pin of an external
EEPROM. The SCL output is used to strobe data at a rate of
50kHz out of the EEPROM. An external pull up resistor in not
needed.
Configuration Reload (RLOAD)
A falling edge on the RLOAD pin, will trigger a register update
from the external EEPROM. This feature may be used during
calibration to load updated register data in the SA2007P. For
normal operation of the SA2007P the RLOAD pin may be left
floating.
OUTPUT SIGNALS
Motor output (MOP, MON)
The motor pulse width is programmable for 71ms and 142ms.
The MON pulse will follow the MOP pulse within the selected
pulse width time. This prevents that the motor armature is in
the wrong position after a power failure. Both MOP and MON
outputs are active high. One energy pulse is represented by a
MOP pulse followed by a MON pulse. The motor drive wave
forms are shown in figure 4.
LED output (LED)
Three options for the LED output pulse rate are available, 6400
and 3200 pulses per kWh, as well as a pulse rate of 1252
pulses per second at rated conditions. At 1252 pulse per
second t_LED is 71µs, for the other options t_LED is 10ms. The LED
output is active low as in figure 5.
An integrated anti-creep function prevents any output pulses if
the measured power is less than 0.02% of the meters rated
current.
MOP
VDD
VSS
Selected Input Indicator (SEL1)
The SA2007P continuously compares the power
consumptions on current channel 1 inputs and current channel
2 inputs. The larger of the two measurements is used for
metering. The SEL1 output pin indicates which channel is
currently being used for the pulse output.
Signal
Output
SEL 1
Value
Description
0 Channel 1 selected (IIN1/IIP1)
1 Channel 2 selected (IIN2/IIP2)
Switching between channels will not be faster than once per
second in case both channels are balanced.
Earth Loop Tamper Indication (ELT)
In case the power measurements from both current channels
differ by more than 12.5%, (indicating a earth loop tamper
condition), the ELT output is set to zero. The SA2007P
continues to generate output pulses from the larger of the two
measured powers in this condition. The ELT output is active low.
Direction Indication (DIRO)
The SA2007P provides information about the energy flow
direction of both current channels on pin DIRO .
A logic 1 on pin DIRO indicates reverse energy flow of both
current channels. Reverse energy flow is defined as the
condition where the voltage sense input and current sense
input are out of phase (greater than 90 degrees). Positive
energy flow, when voltage sense and both current sense input
are in phase, is indicated on pin DIRO as a logic 0.
The DIRO output will toggle between 1 and 0 a rate of 1Hz in
case one of the current channels measure positive energy and
the other negative energy. The condition may accure with a
improper installed or tampered meter.
The DIRO pin may be used to drive a LED in order to indicate
reverse energy.
Signal
Output ^Value
Description
1 Reverse energy flow
DIRO
0 Forward energy flow
1Hz Out of phase current channels
MON
VDD
VSS
DR-01559
t_m
t_m
t_m
Figure 4: Motor drive on MON and MOP pins
LED
VDD
VSS
DR-01332
t_LED
Figure 5: LED pulse output
http://www.sames.co.za
5/12
PRELIMINARY