ADE7878ACPZ Analog Devices Inc, ADE7878ACPZ Datasheet - Page 20

• Manufacturer Part Number: ADE7878ACPZ
• Description: IC ENERGY METERING 3PH 40LFCSP
• Manufacturer: Analog Devices Inc

Specifications of ADE7878ACPZ

• Input Impedance: 400 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.4V
• Current - Supply: 22mA
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-WFQFN, CSP Exposed Pad
• Meter Type: 3 Phase
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LFCSP
• No. Of Pins: 40
• Msl: MSL 1 - Unlimited
• Peak Reflow Compatible (260 C): Yes
• Supply Voltage Min: 3V
• Rohs Compliant: Yes
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADE7878
this signifies all phase currents stayed below threshold and,
therefore, there is no current flowing through the system. At
this point, the external microprocessor should set the ADE7878
in Sleep Mode PSM3. If 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 ADE7878 pins. This situation is often called missing neutral
and is considered a tampering situation, at which point the
external microprocessor should set the ADE7878 in PSM1
mode, measure mean absolute values of phase currents, and
integrate the energy based on their values and the nominal
voltage.
It is recommended to use the ADE7878 in PSM2 mode when
Bits[2:0] (PGA1) of the Gain[15:0] register are equal to 1 or 2.
These bits represent the gain in the current channel datapath. It
is not recommended to use the ADE7878 in PSM2 mode when
the PGA1 bits are equal to 4, 8, or 16.
IRQ pin is triggered low at the end of a measurement period,
IA CURRENT
Figure 22. PSM2 Mode Triggering IRQ1 Pin for LPLINE = 2, 50 Hz Systems
0
IRQ 1
PHASE
COUNTER = 1
POWERED UP
ADE7878
0V
PHASE
COUNTER = 2
LPLINE = 2
IRQ pin is triggered low at the
3.3V – 10%
2.0V ± 10%
1
PHASE
COUNTER = 3
TURNED ON
POR TIMER
26ms
THRESHOLD
LPOIL
Figure 23. Power-Up Procedure
ENTER PSM3
Rev. 0 | Page 20 of 92
ADE7878
MICROPROCESSOR
SETS ADE7878
PSM3—SLEEP MODE
In this mode, the ADE7878 has most of the internal circuits
turned off and the current consumption is at its lowest level.
The I
mode, and the RESET, SCLK/SCL, MOSI/SDA, and SS/HSA
pins should be set high.
POWER-UP PROCEDURE
The ADE7878 contains an on-chip power supply monitor that
supervises the power supply (VDD). At power-up, until VDD
reaches 2 V ± 10%, the chip is in an inactive state. As VDD
crosses this threshold, the power supply monitor keeps the chip
in this inactive state for an additional 26 ms, allowing VDD to
achieve 3.3 V − 10%, the minimum recommended supply
voltage. Because the PM0 and PM1 pins have internal pull-up
resistors and the external microprocessor keeps them high, the
ADE7878 always powers-up in sleep mode (PSM3). Then, an
external circuit (that is, a microprocessor) sets the PM1 pin to a
low level, allowing the ADE7878 to enter normal mode (PSM0).
The passage from PSM3 mode, in which most of the internal
circuitry is turned off, to PSM0 mode, in which all functionality
is enabled, is accomplished in less than 40 ms (see Figure 23 for
details).
When the ADE7878 enters PSM0 mode, the I
active serial port. If the SPI port is used, then the SS/HSA pin
must be toggled three times high to low. This action selects the
SPI port for further use. If I
(I2C_LOCK) of CONFIG2[7:0] must be set to 1 to lock it in.
From this moment, the ADE7878 ignores spurious toggling of
the SS/HSA pin, and an eventual switch to use the SPI port is no
longer possible. Likewise, if SPI is the active serial port, any write
to the CONFIG2[7:0] register locks the port, at which time a
switch to use the I
IN PSM0
2
C, HSDC, and SPI ports are not functional during this
40ms
TRIGGERED
INTERRUPT
RSTDONE
2
C port is no longer possible.
MICROPROCESSOR
MAKES THE
CHOICE BETWEEN
I
2
C AND SPI
2
C is the active serial port, Bit 1
PSM0 READY
ADE7878
2
C port is the