bq2201
Power-Fail Control
(TA = TOPR)
Symbol
t
PF
t
FS
t
PU
t
CED
Parameter
V
CC
slew, 4.75V to 4.25V
V
CC
slew, 4.25V to V
SO
V
CC
slew, 4.25V to 4.75V
Chip-enable propagation
delay
Chip-enable recovery
Minimum
300
10
0
-
Typical
-
-
-
7
Maximum
-
-
-
10
Unit
µs
µs
µs
ns
Time during which SRAM is
write-protected after V
CC
passes V
PFD
on power-up.
Delay after V
CC
slews down
past V
PFD
before SRAM is
write-protected.
Notes
t
CER
40
80
120
ms
t
WPT
Note:
Write-protect time
40
100
150
µs
Typical values indicate operation at T
A
= 25°C.
Caution: Negative undershoots below the absolute maximum rating of -0.3V in battery-backup mode
may affect data integrity.
Power-Down Timing
tPF
4.75
VPFD
tFS
4.25
VSO
VCC
CE
tWPT
CECON
VOHB
TD220102.eps
Oct. 1998 D
6
TI [ TEXAS INSTRUMENTS ]
