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9.2.2. AC Characteristics (2)
Table 8 FOUT symmetry
Item
FOUT symmetry
10. Interface timing when power ON / OFF
10.1. Restrictions of SPI-Bus interface in the power ON / OFF.
t
is needed for a proper power-on reset. If this power-on condition cannot be kept, it is necessary to reset the device by means
R1
of a software command.
After all power-OFF, keep VDD = VBAT = GND for more than 10 seconds for a proper power-on reset by cold start.
When cannot it, please initialize the RTC by software.
The backup period against this standard does not indicate the noise characteristics with respect to the power supply.
The backup period should be long enough (60 seconds or more).
Power supply V
,V
DD
BAT
V
, V
*3
DD
BAT
+V
V
CLK
GND
t
R1
SPI
t
CL
Figure 14 Power on Sequence
Table 9 Power up down characteristics
Item
Initial power supply rise
time
Access wait time
(Initial power on)
Backup switchover start
wait time
Power supply fall time
Power supply rise time
(Recovery from Backup)
Access wait time
(Recovery from Backup)
1 Power-on reset is performed at the rising edge of V
2 Since the V
voltage monitoring (+V
DD
+V
until the power supply switches.
DET1
*3 For internal initialization, the V
RX4111CE
ETM62E-02
Unless otherwise specified､GND=0 V , V
Symbol
SYM
*1
DET
Access is enabled
*2
Symbol
Condition
t
From GND to V
R1
After arrival to V
t
CL
t
After the access end
CD
t
From V
F
DD
t
Recovery to the operating voltage
R2
The time from Recovery from
t
CU
Backup to access start
BAT
) during backup is intermittent operation (31.25 ms) , a delay occurs after V
DET1
voltage at the initial power-on must be increased to 1.6 V or more.
DD
Seiko Epson Corporation
10. Interface timing when power ON / OFF
IO
Condition
Min.
50 % V
Level
40
IO
Backup mode
-V
DET
V
BAT
V
DD
Access is disabled
Min.
0.1
5 V
= +V
DD
DET1
0.5
3 V
= 1.6 V
30
DD
0
to V
= -V
1
DD
DET1
0.1
40
or V
.
DD
= 1.6 V 5.5 V , Ta= -40 C +85 C
Typ.
Max.
60
+V
DET
Access is
enabled
t
CU
Typ.
Max.
-
10
-
10
-
-
-
-
-
-
-
-
-
-
Jump to
Unit
%
Unit
ms / V
ms / V
ms
ms
ms / V
ms / V
ms
reaches
DD
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/
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13
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