Datasheet

ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
Rev. B | Page 35 of 152
USING THE POWER SUPPLY FEATURES
In an energy meter application, the 3.3 V power supply (V
DD
) is
typically generated from the ac line voltage and regulated to 3.3 V
by a voltage regulator IC. The preregulated dc voltage, typically
5 V to 12 V, can be connected to V
DCIN
through a resistor divider.
A 3.6 V battery can be connected to V
BAT
. Figure 34 shows how
the ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/
ADE7569 power supply inputs are set up in this application.
Figure 35 shows the sequence of events that occurs if the main
power supply generated by the PSU starts to fail in the power
meter application shown in Figure 34. The SAG detection can
provide the earliest warning of a potential problem on V
DD
.
When a SAG event occurs, user code can be configured to back up
data and prepare for battery switchover if desired. The relative
spacing of these interrupts depends on the design of the power
supply.
Figure 36 shows the sequence of events that occurs if the main
power supply starts to fail in the power meter application shown
in Figure 34, with battery switchover on low V
DCIN
or low V
DD
enabled.
Finally, the transition between V
DD
and V
BAT
and the different
power supply modes (see the Operating Modes section) are
represented in Figure 37 and Figure 38.
VOLTAGE
SUPERVISORY
POWER SUPPLY
MANAGEMENT
IPSMF SFR
(ADDR. 0xF8)
V
SW
V
BAT
V
SWOUT
V
DD
58
61
60
VOLTAGE
SUPERVISORY
64
V
DCIN
3.3V
REGULATOR
5V TO 12V DC
PSU
50
SAG
DETECTION
49
45
BCTRL
V
P
V
N
(240V, 220V, 110V TYPICAL)
AC INPUT
06353-013
Figure 34. Power Supply Management for Energy Meter Application
t
1
t
2
V
DD
V
DCIN
V
P
– V
N
2.75V
1.2V
SAG LEVEL TRIP POINT
SAGCYC = 1
SAG EVENT
(FSAG = 1)
V
DCIN
EVENT
(FVDCIN = 1)
IF SWITCHOVER ON LOW V
DD
IS ENABLED,
AUTOMATIC BATTERY SWITCHOVER
OCCURS. V
SWOUT
IS CONNECTED TO V
BAT
.
BSO EVENT
(FBSO = 1)
06353-014
Figure 35. Power Supply Management Interrupts and Battery Switchover with Only V
DD
Enabled for Battery Switchover