ADE7760ARSRL Analog Devices Inc, ADE7760ARSRL Datasheet - Page 11

• Manufacturer Part Number: ADE7760ARSRL
• Description: IC ENERGY METER W/OCFD 20SSOP TR
• Manufacturer: Analog Devices Inc

Specifications of ADE7760ARSRL

• Rohs Status: RoHS non-compliant
• Input Impedance: 400 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 4mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP (0.200", 5.30mm Width)
• Meter Type: Single Phase
• Lead Free Status / Rohs Status: Not Compliant

OPERATION
POWER SUPPLY MONITOR
The ADE7760 contains an on-chip power supply monitor. The
power supply (V
If the supply is less than 4 V ± 5%, the ADE7760 goes into an
inactive state, that is, no energy is accumulated and the CF, F1,
and F2 outputs is disabled. This is useful to ensure correct
device operation at power-up and during power-down. The
power supply monitor has built-in hysteresis and filtering. This
gives a high degree of immunity to false triggering due to noisy
supplies.
The power supply and decoupling for the part should be such
that the ripple at V
normal operation.
ANALOG INPUTS
Channel V1 (Current Channel)
The voltage outputs from the current transducers are connected
to the ADE7760 here. Channel V1 has two voltage inputs, V
and V
However, at any one time, only one is selected to perform the
power calculation (see the Fault Detection section).
The maximum peak differential signal on V
is ±660 mV. Figure 9 shows the maximum signal levels on V
V
be referenced to a common mode such as AGND.
REVP - FAULT - CF -
+660mV + V
–660mV + V
1B
F1 - F2 OUTPUTS
, and V
ADE7760
1B
. These inputs are fully differential with respect to V
V
CM
CM
V
V
CM
1N
1A
DD
5V
4V
0V
. The differential voltage signal on the inputs must
, V
Figure 9. Maximum Signal Levels, Channel 1
Figure 8. On-Chip Power Supply Monitoring
INACTIVE
1B
DD
) is continuously monitored by the ADE7760.
DD
COMMON MODE
does not exceed 5 V ± 5% as specified for
±100mV MAX
DIFFERENTIAL INPUT B
DIFFERENTIAL INPUT A
±660mV MAX PEAK
±660mV MAX PEAK
ACTIVE
TIME
AGND
V
CM
INACTIVE
1A
–V
V1
V1
1N
V
V
V
1A
1N
1B
and V
1B
–V
1A
1N
1A
Rev. 0 | Page 11 of 24
.
1N
,
Channel V2 (Voltage Channel)
The output of the line voltage transducer is connected to the
ADE7760 at this analog input. Channel V2 is a single-ended
voltage input. The maximum peak differential signal on
Channel 2 is ±660 mV with respect to V
maximum signal levels that can be connected to Channel 2.
The differential voltage V
common mode (usually AGND). The analog inputs of the
ADE7760 can be driven with common-mode voltages of up to
100 mV with respect to AGND. However, the best results are
achieved using a common mode equal to AGND.
Typical Connection Diagrams
Figure 11 shows a typical connection diagram for Channel V1.
The analog inputs are being used to monitor both the phase and
neutral currents. Because of the large potential difference
between the phase and neutral, two current transformers (CTs)
must be used to provide the isolation. Note that both CTs are
referenced to AGND (analog ground); the common-mode
voltage is, therefore, 0 V. The CT turns ratio and burden resistor
(RB) are selected to give a peak differential voltage of ±660 mV.
Figure 12 shows two typical connections for Channel V2. The
first option uses a potential transformer (PT) to provide
complete isolation from the main voltage. In the second option,
the ADE7760 is biased around the neutral wire, and a resistor
divider is used to provide a voltage signal that is proportional to
the line voltage. Adjusting the ratio of RA and RB + VR is a
convenient way of carrying out a gain calibration on the meter.
+660mV + V
–660mV + V
IP
IN
V
CM
CM
CM
AGND
V2
Figure 10. Maximum Signal Levels, Channel 2
Figure 11. Typical Connection for Channel 1
CT
CT
RB
RB
DIFFERENTIAL INPUT
2P
±660mV MAX PEAK
–V
COMMON MODE
2N
R
R
±100mV MAX
F
F
must be referenced to a
C
C
F
F
2N
V
V
V
. Figure 10 shows the
1A
1N
1B
V2
V
CM
V
V
2P
2N
ADE7760