RV-8564 Datasheet, PDF (28/40 Pages) MICORO CRYSTAL SWITZERLAND – I2C-Bus Interface Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8564
11.3. INTERFACE WATCHDOG TIMER
During read/write operations, the time counting circuits are frozen. To prevent a situation where the accessing
device becomes locked and does not clear the interface, the RV-8564 has a built in watchdog timer. Should the
interface be active for more than 1 s from the time a valid slave address is transmitted, then the RV-8564 will
automatically clear the interface and allow the time counting circuits to continue counting.
The watchdog is implemented to prevent the excessive loss of time due to interface access failure e. g. if main
power is removed from a battery backup system during an interface access.
Each time the watchdog period is exceeded, 1 s will be lost from the time counters. The watchdog will trigger
between 1 s and 2 s after receiving a valid slave address.
12.ABSOLUTE MAXIMUM RATING
PARAMETER
Supply voltage
Input voltage
Output voltage
Supply current
DC Input current
DC Output current
Electrostatic discharge voltage
Latch-up current
Operating temperature range
Storage temperature range
SYMBOL
VDD
VI
VO
IDD; ISS
II
IO
VESD
ILU
TOPR
TSTO
CONDITIONS
> GND / < VDD
Input Pin
INT Pin
VDD Pin
HBM¹⁾
MM²⁾
All pins³⁾
Stored as bare product
MIN.
-0.5
VSS -0.5
VSS -0.5
-50
-10
-10
-
-
-
-40
-55
1) _{Pass level; Human Body Model (HBM), according to JESD22-A114.}
2) _{Pass level; Machine Model (MM), according to JESD22-A115.}
3) _{Pass level; latch-up testing, according to JESD78 at maximum ambient temperature (Tamb(max) = +85°C).}
MAX.
+6.5
VDD +0.5
VDD +0.5
+50
+10
+10
+/-3500
+/-250
100
+85
+125
UNIT
V
V
V
mA
mA
mA
V
V
mA
°C
°C
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