PCF8564A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 3 — 26 August 2013 25 of 48
NXP Semiconductors
PCF8564A
Real time clock and calendar
10.3 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
PCF8564A 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 PCF8564A will automatically
clear the interface and allow the time counting circuits to continue counting. The watchdog
will trigger between 1 s and 2 s after receiving a valid slave address. Each time the
watchdog period is exceeded, 1 s will be lost from the time counters.
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 backed-up system during an
interface access.
a. Correct data transfer: read or write
b. Incorrect data transfer; read or write
Fig 19. Interface watchdog timer
DDD
6/$9($''5(66
UXQQLQJ
WLPH
FRXQWHUV
:'WLPHU
GDWD
:'WLPHUWUDFNLQJ
WLPHFRXQWHUVIUR]HQ UXQQLQJ
'$7$
WV
'$7$ 672367$57
DDD
6/$9($''5(66
UXQQLQJ
WLPH
FRXQWHUV
:'WLPHU
GDWD
:'WLPHUWUDFNLQJ
WLPHFRXQWHUVIUR]HQ UXQQLQJ
'$7$
VWV
'$7$67$57
GDWDWUDQVIHUIDLO
:'WULSV
PCF8564A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 3 — 26 August 2013 26 of 48
NXP Semiconductors
PCF8564A
Real time clock and calendar
11. Internal circuitry
12. Safety notes
Fig 20. Device diode protection diagram
DDD
6'$
6&/
9
''
&/.2(
26&,
26&2
9
66
3&)$
,17
&/.287
CAUTION
This device is sensitive to ElectroStatic Discharge (ESD). Observe precautions for handling
electrostatic sensitive devices.
Such precautions are described in the ANSI/ESD S20.20, IEC/ST 61340-5, JESD625-A or
equivalent standards.
CAUTION
Semiconductors are light sensitive. Exposure to light sources can cause the IC to
malfunction. The IC must be protected against light. The protection must be applied to all
sides of the IC.
PCF8564A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 3 — 26 August 2013 27 of 48
NXP Semiconductors
PCF8564A
Real time clock and calendar
13. Limiting values
[1] Pass level; Human Body Model (HBM) according to Ref. 5 “JESD22-A114.
[2] Pass level; Machine Model (MM), according to Ref. 6 “
JESD22-A115.
[3] Pass level; latch-up testing, according to Ref. 7 “
JESD78 at maximum ambient temperature (T
amb(max)
).
[4] According to the NXP store and transport conditions (see Ref. 11 “
UM10569) the devices have to be stored at a temperature of +5 C
to +45 C and a humidity of 25 % to 75 %.
Table 29. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
V
DD
supply voltage 0.5 +6.5 V
V
I
input voltage 0.5 +6.5 V
V
O
output voltage 0.5 +6.5 V
I
DD
supply current 50.0 +50.0 mA
I
I
input current 10.0 +10.0 mA
I
O
output current 10.0 +10.0 mA
I
SS
ground supply current 50.0 +50.0 mA
P
tot
total power dissipation - 300 mW
V
ESD
electrostatic
discharge voltage
HBM
[1]
- 3500 V
MM
[2]
- 250 V
I
lu
latch-up current all pins but OSCI
[3]
-100mA
T
stg
storage temperature
[4]
65 +150 C
T
amb
ambient temperature operating device 40 +85 C

PCF8564ACX9/B/1,02

Mfr. #:
Manufacturer:
NXP Semiconductors
Description:
IC RTC CLK/CALENDAR I2C DIE
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union