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Switching Characteristics
Timing Requirements
PCA9518
EXPANDABLE FIVE-CHANNEL I
2
C HUB
SCPS132A – JUNE 2006 – REVISED JULY 2007
over operating free-air temperature range (unless otherwise noted) (see Figure 2 )
(1)
FROM TO
PARAMETER MIN TYP MAX UNIT
(INPUT) (OUTPUT)
t
PHLs
(2)
105 202 389 ns
SDA or SCL SDAn or SCLn
t
PLHs
(3)
105 259 265 ns
t
PHLE1s
Propagation delay 109 193 327 ns
EXPSDA1 or EXPSCL1 SDA or SCL
t
PLHE1s
120 153 200 ns
t
PLHE2s
EXPSDA2 or EXPSCL2 SDA or SCL 120 234 279 ns
t
THLs
70% 30% 48 110 187 ns
Output transition time,
SDAn, SCLn
t
TLHs
30% 70% 0.85RC ns
(1) The SDA and SCL propagation delays are dominated by rise times or fall times. The fall times mostly are internally controlled and are
sensitive only to load capacitance. The rise times are RC time-constant controlled and, therefore, a specific numerical value can be
given only for fixed RC time constants.
(2) The SDA high-to-low propagation delay, t
PHLs
, includes the fall time from V
CC
to 0.5 V
CC
of EXPSDA1 or EXPSCL1 and the SDA or SCL
fall time from the quiescent high (usually V
CC
) to below 0.3 V
CC
. The SDA and SCL outputs have edge-rate-control circuits included that
make the fall time almost independent of load capacitance.
(3) The SDA or SCL low-to-high propagation delay, t
PLHs
, includes the rise-time constant from the quiescent low to 0.5 V
CC
for EXPSDA1 or
EXPSCL2, the rise-time constant for the quiescent low to 0.5 V
CC
for EXPSDA1 or EXPSCL1, and the rise time constant from the
quiescent externally driven low to 0.7 V
CC
for SDA or SCL.
over operating free-air temperature range (unless otherwise noted)
PARAMETER MIN MAX UNIT
t
su
Setup time, EN ↑ before Start condition 300 ns
t
h
Hold time, EN ↓ after Stop condition 300 ns
8
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