
DS1254
8 of 17
AC ELECTRICAL CHARACTERISTICS
(VCC = 3.3V 10%, TA = 0
C to +70C.)
PARAMETER
SYMBOL
MIN
MAX
UNITS
NOTES
Read Cycle Time
tRC
150
ns
Address Access Time
tAAC
150
ns
OE to Output Valid
tOE
75
ns
CE to Output Valid
tCO
150
ns
CE or OE to Output Active
tCOE
0
ns
2
Output High-Z from Deselection
tOD
70
ns
2
Output Hold from Address Change
tOH
5
ns
Write Cycle Time
tWC
150
ns
WE, CE Pulse Width
tWP
100
ns
5
Address Setup Time
tAW
10
ns
tAH1
5
ns
6
Address Hold Time
tAH2
25
ns
7
Output High-Z from
WE
tODW
70
ns
2
Output Active from
WE
tOEW
5
ns
2
Data Setup Time
tDS
60
ns
8
tDH1
0
ns
6
Data Hold Time
tDH2
20
ns
8
Read Recovery (Clock Access Only)
tRR
20
ns
Write Recovery (Clock Access Only)
tWR
20
ns
POWER-UP/POWER-DOWN CHARACTERISTICS
(VCC = 3.3V 10%)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
CE and WE at V
IH Before Power-Down
tPD
0
s
VCC Fall Time: VPF(MAX) to VPF(MIN)
tF
300
s
VCC Fall Time: VPF(MIN) to VBAT
tFB
10
s
VCC Rise Time: 0V to VPF(MIN)
tR
150
s
VCC Valid to End of Write Protection
tREC
125
ms
VCC Valid to BW Valid
tBPU
1
s
3
(TA = +25
C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Expected Data-Retention Time (Oscillator On)
tDR
10
years
4
WARNING: Under no circumstances are negative undershoots, of any amplitude, allowed when
device is in battery-backup mode.