7
FN8100.4
May 18, 2006
Write Cycle Timing
Power-up Timing
Notes: (1) Delays are measured from the time VCC is stable until the specified operation can be initiated. These parameters are not 100% tested.
VCC slew rate should be between 0.2mV/sec and 50mV/sec.
(2) Typical values are for TA = 25°C and VCC = 5.0V
Nonvolatile Write Cycle Timing
Note:
(1) tWC 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. It is
the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used.
WATCHDOG TIMER/LOW VOLTAGE RESET OPERATING CHARACTERISTICS
Watchdog/Low Voltage Reset Parameters (SeeFigures 3 and 4)
SCL
SDA
tWC
8th Bit of Last Byte
ACK
Stop
Condition
Start
Condition
Symbol
Parameter
Min.
Typ.(2)
Max.
Units
tPUR(1)
Time from Power-up to Read
1
ms
tPUW(1)
Time from Power-up to Write
5
ms
Symbol
Parameter
Min.
Typ.(1)
Max.
Units
tWC(1)
Write Cycle Time
5
10
ms
Symbols
Parameters
Min.
Typ.
Max.
Unit
VPTRIP
Programmed Reset Trip Voltage
X1228-4.5A
X1228
X1228-2.7A
X1228-2.7
4.50
4.25
2.75
2.55
4.63
4.38
2.85
2.65
4.75
4.50
2.95
2.75
V
tRPD
VCC Detect to RESET LOW
500
ns
tPURST
Power-up Reset Time-out Delay
100
250
400
ms
tF
VCC Fall Time
10
s
tR
VCC Rise Time
10
s
tWDO
Watchdog Timer Period (Crystal = 32.768kHz):
WD1 = 0, WD0 = 0
WD1 = 0, WD0 = 1
WD1 = 1, WD0 = 0
1.7
725
225
1.75
750
250
1.8
775
275
s
ms
tRST
Watchdog Reset Time-out Delay (Crystal=32.768kHz)
225
250
275
ms
tRSP
2-Wire interface
1
s
VRVALID
Reset Valid VCC
1.0
V
X1228