Rainbow Electronics DS1254 - Manual (Page 12)

DS1254
12 of 17
Figure 9. POWER-UP/POWER-DOWN WAVEFORM TIMING (Note 14)
V
CC
V
PF(max)
V
PF(min)
t
F
t
FB
t
PD
t
DR
V
BAT
t
REC
t BPU
Slews with V CC
BW
t R
Slews with V CC
CE
WE
,
POWER-UP/POWER-DOWN CHARACTERISTICS (V
CC
= 5V
±
10%)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
CE and WE at V
IH
Before Power Down
t
PD
0
µ
S
V
CC
Fall Time: V
PF(max)
to V
PF(min)
t
F
300
µ
S
V
CC
Fall Time: V
PF(min)
to V
BAT
t
FB
10
µ
S
V
CC
Rise Time: 0V to V
PF(min)
t
R
150
µ
S
V
CC
Valid to End of Write Protection t
REC
125 mS
V
CC
Valid to BW Valid
t
BPU
1 Sec 3
(T
A
= +25
°
C )
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Expected Data Retention Time
(Oscillator On)
t
DR
10 years 4
Warning: Under no circumstances are negative undershoots, of any amplitude, allowed when device is
in battery-backup mode.