Datasheet

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8.5.5Bus-RelatedCharacteristicsoftheSDAandSCLI/OStagesforF/S-ModeI
2
C-Bus
SDA
SCL
t
f
t
SU-DAT
t
HD-STA
t
r
t
BUF
t
SU-STO
P S
t
SP
t
SU-STA
Sr
t
HIGH
t
HD-DAT
t
LOW
t
r
t
HD-STA
S
t
f
T0114-01
TAS3108,TAS3108IA
AUDIODIGITALSIGNALPROCESSORS
SLES152B–OCTOBER2005–REVISEDNOVEMBER2007
Devices
AllvaluesarereferredtoV
IHmin
andV
ILmax
(seeSection8.5.4).
A
STANDARDMODEFASTMODE
TEST
PARAMETERUNIT
CONDITIONS
MINMAXMINMAX
f
SCL
SCLclockfrequency
(1)
0
(1)
1000
(1)
400
(2)
kHz
Holdtime(repeated)STARTcondition.
t
HD-STA
Afterthisperiod,thefirstclockpulseis4
(1)
0.6
(1)
µs
generated.
t
LOW
LOWperiodoftheSCLclock4.7
(1)
1.3
(1)
µs
t
HIGH
HIGHperiodoftheSCLclock4
(1)
0.6
(1)
µs
t
SU-STA
SetuptimeforrepeatedSTART4.7
(1)
0.6
(1)
µs
t
SU-DAT
Datasetuptime250
(1)
100
(1)
ns
t
HD-DAT
Dataholdtime
(3)(4)
0
(1)
3.45
(1)
0
(1)
0.9
(1)
µs
20+0.1
t
r
RisetimeofbothSDAandSCLsignals1000
(1)
300
(1)
ns
C
b
(5)(1)
20+0.1
t
f
FalltimeofbothSDAandSCL300
(1)
300
(1)
ns
C
b
(5)(1)
t
SU-STO
SetuptimeforSTOPcondition4
(1)
0.6
(1)
µs
BusfreetimebetweenaSTOPand
t
BUF
4.7
(1)
1.3
(1)
µs
STARTcondition
C
b
Capacitiveloadforeachbusline400
(1)
400
(1)
pF
NoisemarginattheLOWlevelforeach
V
nL
0.1V
DVDD
(1)
0.1V
DVDD
(1)
V
connecteddevice(includinghysteresis)
NoisemarginattheHIGHlevelforeach
V
nH
0.2V
DVDD
(1)
0.2V
DVDD
(1)
V
connecteddevice(includinghysteresis)
(1)Thismeasurementisspecifiedbydesign.
(2)Inmastermode,themaximumspeedis375kHz.
(3)NotethatSDAdoesnothavethestandardI
2
Cspecification300-nsinternalholdtime.SDAmustbevalidbytherisingandfallingedges
ofSCL.TIrecommendsthata2-kΩpullupresistorbeusedtoavoidpotentialtimingissues.
(4)Afast-modeI
2
C-busdevicecanbeusedinastandard-modeI
2
C-bussystem,buttherequirementt
SU-DAT
≥250nsmustthenbemet.
ThisisautomaticallythecaseifthedevicedoesnotstretchtheLOWperiodoftheSCLsignal.IfsuchadevicedoesstretchtheLOW
periodoftheSCLsignal,itmustoutputthenextdatabittotheSDAlinet
r-max
+t
SU-DAT
=1000+250=1250ns(accordingtothe
standard-modeI
2
Cbusspecification)beforetheSCLlineisreleased.
(5)C
b
=totalcapacitanceofonebuslineinpF.
Figure8-4.StartandStopConditionsTimingWaveforms
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