Rainbow Electronics DS1254 User Manual
Page 14
DS1254
14 of 17
NOTES:
1) Voltage referenced to ground.
2) These parameters are sampled with a 50pF load and are not 100% tested.
3)
BW
is an open-drain output and, as such, cannot source current. An external pullup resistor should be
connected to this pin for proper operation.
BW
can sink 10mA.
4) The DS3800 battery cap is a one-time use part, but can be removed and replaced. By Design, DS3800
removal will mechanically damage the battery cap, which eliminates the accidental use of a
previously attached and possibly low capacity battery cap.
5) t
WP
specified as the logical AND of
CE
and
WE
, t
WP
is measured from the latter of
CE
or
WE
going
low to the earlier of
CE
or
WE
going high.
6) T
AH1
, t
DH1
are measured from
WE
going high.
7) T
AH2
, t
DH2
are measured from
CE
going high.
8) t
DS
is measured from the earlier of
CE
or
WE
going high.
9)
WE
is high for a read cycle.
10)
OE
= V
IH
or V
IL
. If
OE
= V
IH
during write cycle, the output buffers remain in a high- impedance state.
11) If the
CE
low transition occurs simultaneously with or later than the
WE
low transition in a write-
enable-controlled write cycle, the output buffers remain in a high- impedance state during this period.
12) If the
CE
high transition occurs prior to or simultaneously with the
WE
high transition, the output
buffers remain in a high- impedance state during this period.
13) If
WE
is low or the
WE
low transition occurs prior to or simultaneously with the
CE
low transition,
the output buffers remain in a high impedance state during this period.
14) In a power-down condition, the voltage on any pin cannot exceed the voltage on V
CC
.