X1227 Xicor, X1227 Datasheet - Page 19

• Manufacturer Part Number: X1227
• Description: Real Time Clock/Calendar/CPU Supervisor with EEPROM
• Manufacturer: Xicor

X1227
Write Cycle Timing
Power Up Timing
Notes: (1) Delays are measured from the time V
Nonvolatile Write Cycle Timing
Note: (1) t
WATCHDOG TIMER/LOW VOLTAGE RESET OPERATING CHARACTERISTICS
Watchdog/Low Voltage Reset Parameters (See Figures 3 and 4)
REV 1.1.20 1/13/03
Symbols
V
V
t
PURST
RVALID
t
t
t
t
PTRIP
WDO
Symbol
Symbol
RPD
RST
RSP
t
t
t
t
PUW
(2) Typical values are for T
t
F
R
PUR
WC
SDA
SCL
It is the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used.
(1)
WC
(1)
tested. V
(1)
is the time from a valid stop condition at the end of a write sequence to the end of the self-timed internal nonvolatile write cycle.
Programmed Reset Trip Voltage
X1227-4.5A
X1227
X1227-2.7A
X1227-2.7
V
Power Up Reset Time-out Delay
V
V
Watchdog Timer Period (Crystal=32.768kHz):
WD1=0, WD0=0
WD1=0, WD0=1
WD1=1, WD0=0
Watchdog Reset Time-out Delay (Crystal=32.768kHz)
2-Wire interface
Reset Valid V
CC
CC
CC
CC
Detect to RESET LOW
Fall Time
Rise Time
8th Bit of Last Byte
slew rate should be between 0.2mV/µsec and 50mV/µsec.
Time from Power Up to Read
Time from Power Up to Write
Write Cycle Time
CC
A
= 25°C and V
Parameters
Parameter
Parameter
CC
CC
= 5.0V
ACK
is stable until the specified operation can be initiated. These parameters are not 100%
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Condition
Stop
Min.
Min.
t
Min.
WC
4.50
4.25
2.75
2.55
100
725
225
225
1.7
1.0
10
10
1
Characteristics subject to change without notice.
Condition
Typ.
Typ.
Start
5
Typ.
4.63
4.38
2.85
2.65
1.75
250
750
250
(2)
(1)
250
Max.
Max.
10
1
5
Max.
4.75
4.50
2.95
2.75
500
400
775
275
275
1.8
Units
Units
ms
ms
ms
Unit
ms
ms
ms
ms
ns
µs
µs
µs
19 of 28
V
V
s