ISL12027 Intersil Corporation, ISL12027 Datasheet - Page 24

• Manufacturer Part Number: ISL12027
• Manufacturer: Intersil Corporation

• Mode B - In this mode the selection bits indicate
• Mode C - In this mode the selection bits indicate a low
(X12028
MODE
mode)
switchover to battery backup at V
communications in battery backup. In order to
communicate in battery backup mode, the V
must be less than the V
greater than V
must go to V
as the normal operating mode of the X1228 device
V
DD
A
B
C
D
switchover combined with no communications in
TABLE 9. I
SBIB
V
BIT
I
0
0
1
1
DD
BAT
BAT
RESET
RESET
to communicate. This mode is the same
2
C, LV RESET, AND BATTERY BACKUP OPERATION SUMMARY (Shaded Row is same as X12028 operation)
BSW
V
(2.2V)
BIT
TRIP
0
1
0
1
. Also, pullups on the I
V
BAT
RESET
Standard Mode,
Standard Mode,
SWITCHOVER
24
Legacy Mode,
Legacy Mode,
V
V
V
V
voltage AND V
VOLTAGE
V
TRIP
TRIP
(2.63V)
DD
DD
BAT
VBAT
typ
typ
< V
< V
= 2.2V
= 2.2V
(3.0V)
DD
FIGURE 29. EXAMPLE RESET OPERATION IN MODE A OR C
BAT
BAT
(VDD power, V
<V
BAT
I
, and I
V
2
DD
2
C ACTIVE IN
RESET
YES, only if
C bus pins
BAT
BACKUP?
BATTERY
must be
tPURST
>V
NO
NO
NO
BAT
2
RESET
C
voltage
not connected)
ISL12027
READ IN BATTERY
EE PROM WRITE/
BACKUP?
I
2
C Bus Active
YES
NO
NO
NO
• Mode D - In this mode the selection bits indicate
.
battery backup. Operation is actually identical to Mode A
with I
communications (see Figure 28).
switchover to battery backup at V
communications in battery backup. This mode is unique in
that there is I
than V
the safest for guaranteeing I
there is a Valid V
2
C communications down to V
RESET
FREQ/IRQ
ACTIVE?
2
YES
YES
or V
N/A
Yes
C communication as long as V
DD
BAT
(see Figure 29).
, whichever is greater. This mode is
Operation of I
V
communications. Battery switchover
at V
Operation of I
backup mode, but only for
V
Bus must have pullups to V
Operation of I
V
communications. Battery switchover
at V
Operation of I
or V
RESET
BAT
RESET
TRIP
TRIP
BAT
2
> V
C communications only when
(Battery backup mode)
, whichever is higher.
, then below that no
, then below that no
.
.
DD
DD
> V
DD
2
2
2
2
C bus down to V
C bus into battery
C bus down to V
C busdown to V
< V
NOTES
RESET
= V
BAT
RESET
.
, and no I
DD
BAT
is higher
, then no
April 17, 2006
RESET
.
DD
DD
FN8232.3
2
C
=
=