Datasheet

ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
Rev. B | Page 32 of 152
POWER SUPPLY ARCHITECTURE
Each ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/
ADE7569 has two power supply inputs, V
DD
and V
BAT
, which
require only a single 3.3 V power supply at V
DD
for full operation.
A battery backup, or secondary power supply, with a maximum
of 3.7 V can be connected to the V
BAT
input. Internally, the
ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
connect V
DD
or V
BAT
to V
SWOUT
, which is used to derive power for
the device circuitry. The V
SWOUT
output pin reflects the voltage at
the internal power supply (V
SWOUT
) and has a maximum output
current of 6 mA. This pin can also be used to power a limited
number of peripheral components. The 2.5 V analog supply (V
INTA
)
and the 2.5 V supply for the core logic (V
INTD
) are derived by on-
chip linear regulators from V
SWOUT
. Figure 32 shows the power
supply architecture of the ADE7116/ADE7156/ADE7166/
ADE7169/ADE7566/ADE7569.
The ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/
ADE7569 provide automatic battery switchover between V
DD
and V
BAT
based on the voltage level detected at V
DD
or V
DCIN
. In
addition, the BCTRL input can be used to trigger a battery
switchover. The conditions for switching V
SWOUT
from V
DD
to
V
BAT
and back to V
DD
are described in the Battery Switchover
section. V
DCIN
is an input pin that can be connected to a 0 V to
3.3 V dc signal. This input is intended for power supply super-
visory purposes and does not provide power to the ADE7116/
ADE7156/ADE7166/ADE7169/ADE7566/ADE7569 circuitry.
POWER SUPPLY
MANAGEMENT
LDO
V
INTD
LDO
V
INTA
ADC
V
SW
ADC
SCRATCH PAD LCD RTC
TEMPERATURE ADC
3.3V
MCU
ADE
SPI/I
2
C
UART
2.5V
V
DCIN
V
DD
V
BAT
V
SWOUT
BCTRL
*NOT AVAILABLE IN THE ADE7116.
06353-011
*
*
*
Figure 32. Power Supply Architecture
BATTERY SWITCHOVER
The ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/
ADE7569 monitor V
DD
, V
BAT
, and V
DCIN
. Automatic battery switch-
over from V
DD
to V
BAT
can be configured based on the status of
the V
DD
, V
DCIN
, or BCTRL pin. Battery switchover is enabled by
default. Setting Bit 1 in the Battery Switchover Configuration SFR
(BATPR, Address 0xF5) disables battery switchover so that V
DD
is always connected to V
SWOUT
(see Tabl e 19). The source of
V
SWOUT
is indicated by Bit 6 in the Peripheral Configuration SFR
(PERIPH, Address 0xF4), which is described in Table 20 . Bit 6 is
set when V
SWOUT
is connected to V
DD
and cleared when V
SWOUT
is
connected to V
BAT
.
The battery switchover functionality provided by the ADE7116/
ADE7156/ADE7166/ADE7169/ADE7566/ADE7569 allows a
seamless transition from V
DD
to V
BAT
. An automatic battery
switchover option ensures a stable power supply to the device, as
long as the external battery voltage is above 2.75 V. It allows
continuous code execution even while the internal power
supply is switching from V
DD
to V
BAT
and back. Note that the
energy metering ADCs are not available when V
BAT
is being
used for V
SWOUT
.
Power supply monitor (PSM) interrupts can be enabled to
indicate when battery switchover occurs and when the V
DD
power supply is restored (see the Power Supply Management
(PSM) Interrupt section.)
V
DD
to V
BAT
The following three events switch the internal power supply
(V
SWOUT
) from V
DD
to V
BAT
:
• V
DCIN
< 1.2 V. When V
DCIN
falls below 1.2 V, V
SWOUT
switches from V
DD
to V
BAT
. This event is enabled when the
BATPRG[1:0] bits in the battery switchover configuration
SFR (BATPR, Address 0xF5) = 0b01. Setting these bits
disables switchover based on V
DCIN
. Battery switchover on
low V
DCIN
is disabled by default.
• V
DD
< 2.75 V. When V
DD
falls below 2.75 V, V
SWOUT
switches from V
DD
to V
BAT
. This event is enabled when the
BATPRG[1:0] bits in the BATPR SFR are cleared.
• Falling edge on BCTRL. When the battery control pin,
BCTRL, goes low, V
SWOUT
switches from V
DD
to V
BAT
. This
external switchover signal can trigger a switchover to V
BAT
at any time. Setting the INT1PRG bits to X01 in the
interrupt pins configuration SFR (INTPR, Address 0xFF)
enables the battery control pin (see Table 17).
Switching from V
BAT
to V
DD
To s witc h V
SWOUT
from V
BAT
to V
DD
, all of the following events
must be true:
• V
DD
> 2.75 V. V
SWOUT
switches back to V
DD
after V
DD
remains
above 2.75 V.
• V
DCIN
> 1.2 V and V
DD
> 2.75 V. If the low V
DCIN
condition
is enabled, V
SWOUT
switches to V
DD
after V
DCIN
remains
above 1.2 V and V
DD
remains above 2.75 V.
• Rising edge on BCTRL. If the battery control pin is enabled,
V
SWOUT
switches back to V
DD
after BCTRL is high, and the
first or second bullet point is satisfied.