Datasheet

Data Sheet ADE7880
Rev. A | Page 21 of 104
PHASE
COUNTER = 1
PHASE
COUNTER = 2
PHASE
COUNTER = 3
LPLINE[4:0] = 2
IRQ1
IA CURRENT
LPOIL[2:0]
THRESHOLD
10193-008
Figure 33. PSM2 Mode Triggering
IRQ
Pin for LPLINE[4:0] = 2 (50 Hz Systems)
The I
2
C or SPI port is not functional during this mode. The PSM2
mode reduces the power consumption required to monitor the
currents when there is no voltage input and the voltage supply
of the ADE7880 is provided by an external battery. If the
IRQ0
pin is triggered low at the end of a measurement period, this
signifies all phase currents stayed below threshold and,
therefore, there is no current flowing through the system.
At this point, the external microprocessor sets the
into Sleep Mode PSM3. If the
ADE7880
IRQ1
pin is triggered low at the
end of the measurement period, this signifies that at least one
current input is above the defined threshold and current is
flowing through the system, although no voltage is present at
the pins. This situation is often called missing neutral
and is considered a tampering situation, at which point the
external microprocessor sets the into PSM1 mode,
measures the mean absolute values of phase currents, and
integrates the energy based on their values and the nominal
voltage.
ADE7880
ADE7880
It is recommended to use the ADE7880 in PSM2 mode when
Bits[2:0] (PGA1[2:0]) of the Gain register are equal to 1 or 2.
These bits represent the gain in the current channel datapath. It
is not recommended to use the ADE7880 in PSM2 mode when
the PGA1[2:0] bits are equal to 4, 8, or 16.
PSM3—SLEEP MODE (ALL PARTS)
In sleep mode, the ADE7880 has most of its internal circuits
turned off and the current consumption is at its lowest level.
The I
2
C, HSDC, and SPI ports are not functional during this
mode, and the
RESET
, SCLK/SCL, MOSI/SDA, and
SS
/HSA pins
should be set high.
Table 10. Power Modes and Related Characteristics
Power Mode All Registers
1
LPOILVL, CONFIG2 I
2
C/SPI Functionality
PSM0
State After Hardware Reset Set to default Set to default I
2
C enabled
All circuits are active and DSP is in idle
mode.
State After Software Reset Set to default Unchanged
Active serial port is
unchanged if lock-
in procedure has
been previously
executed
All circuits are active and DSP is in idle
mode.
PSM1
Not available PSM0 values retained Enabled
Current mean absolute values are
computed and the results are stored
in the AIMAV, BIMAV, and CIMAV
registers. The I
2
C or SPI serial port is
enabled with limited functionality.
PSM2 Not available PSM0 values retained Disabled
Compares phase currents against the
threshold set in LPOILVL. Triggers
IRQ0
or IRQ1 pins accordingly. The
serial ports are not available.
PSM3 Not available PSM0 values retained Disabled
Internal circuits shut down and the
serial ports are not available.
1
Setting for all registers except the LPOILVL and CONFIG2 registers.