LOW SKEW, 1-TO-8 DIFFERENTIAL/
LVCMOS-TO-LVCMOS FANOUT BUFFER
ICS8308I
IDT™ / ICS™ LVCMOS FANOUT BUFFER 1 ICS8308AGI REV. B OCTOBER 16, 2007
BLOCK DIAGRAM PIN ASSIGNMENT
ICS8308I
24-Lead, 173-MIL TSSOP
4.4mm x 7.8mm x 0.925mm body package
G Package
Top View
Q0
GND
CLK_SEL
LVCMOS_CLK
CLK
nCLK
CLK_EN
OE
VDD
GND
Q1
VDDO
VDDO
Q2
GND
Q3
VDDO
Q4
GND
Q5
VDDO
Q6
GND
Q7
GENERAL DESCRIPTION
The ICS8308I is a low-skew, 1-to-8 Fanout Buffer
and a member of the HiPerClockS™ family of High
Performance Clock Solutions from IDT. The
ICS8308I has two selectable clock inputs. The CLK,
nCLK pair can accept most differential input levels.
The LVCMOS_CLK can accept LVCMOS or LVTTL input levels.
The low impedance LVCMOS/LVTTL outputs are designed to
drive 50Ω series or parallel terminated transmission lines. The
effective fanout can be increased from 8 to 16 by utilizing the
ability of the outputs to drive two series terminated trans-
mission lines.
The ICS8308I is characterized for 3.3V core/3.3V output,
3.3V core/2.5V output or 2.5V core/2.5V output operation.
Guaranteed output and part-part skew characteristics make
the 8308I ideal for those clock distribution applications requiring
well defined performance and repeatability.
FEATURES
•Eight LVCMOS/LVTTL outputs, (7Ω typical output impedance)
•Selectable LVCMOS_CLK or differential CLK, nCLK inputs
•CLK, nCLK pair can accept the following differential
input levels: LVPECL, LVDS, LVHSTL, SSTL, HCSL
•Maximum Output Frequency: 350MHz
•Output Skew: (3.3V± 5%): 100ps (maximum)
•Part to Part Skew: (3.3V± 5%): 1ns (maximum)
•Supply Voltage Modes:
(Core/Output)
3.3V/3.3V
3.3V/2.5V
2.5V/2.5V
•-40°C to 85°C ambient operating temperature
•Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
LVCMOS_CLK
CLK
nCLK
CLK_SEL
CLK_EN
OE
D
LE
Q
1
0
Pullup
Pullup
Pullup
Pulldown
Pullup
Pullup
IDT™ / ICS™ LVCMOS FANOUT BUFFER 2 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 1. PIN DESCRIPTIONS
rebmuNemaNepyTnoitpircseD
,51,31,11,1
32,12,91,71
,6Q,7Q,1Q,0Q
2Q,3Q,4Q,5Q tuptuO.slevelecafretniLTTVL/SOMCVL.stuptuokcolC
22,81,41,01,2DNGrewoP.dnuorgylppusrewoP
3LES_KLCtupnIpulluP
.HGIHnehwtupnikcolcSOMCVLstceleS.tupn
itceleskcolC
.A3elbaTeeS.WOLnehwstupniKLCn,KLCstceleS
.slevelecafretniLTTVL/SOMCVL
4KLC_SOMCVLtupnIpulluP.slevelecafretniLTTVL/SOMCVL.tupnikcolC
5KLCtupnIpulluP.tupnikcolclaitnereffidgnitrevni-noN
6KLCntupnInwodlluP.tupnikcolclaitnereffidgnitrevnI
7NE_KLCtupnIpulluP.slevelecafretniLTTVL/SOMCVL.elbanekcolC
8EOtupnIpulluP .slevele
cafretniLTTVL/SOMCVL.elbanetuptuO
.B3elbaTeeS
9V
DD
rewoP.nipylppuseroC
42,02,61,21V
ODD
rewoP.snipylppustuptuO
:ETON pulluP dna nwodlluP .seulavlacipytrof,scitsiretcarahCniP,2elbaTeeS.srotsisertu
pnilanretniotrefer
TABLE 2. PIN CHARACTERISTICS
TABLE 3A. CLOCK SELECT FUNCTION TABLE
TABLE 3C. CLOCK INPUT FUNCTION TABLE
tupnIlortnoC tupnIkcolC
LES_KLC
0detcelessiKLCn,KLC
1detcelessiKLC_SOMCVL
stupnIstuptuO edoMtuptuOottupnIytiraloP
LES_KLCKLC_SOMCVLKLCKLCn7Q:0Q
0— 0 1 WOLdednEelgniSotlaitnereffiDgnitrevnInoN
0— 1 0 HG
IHdednEelgniSotlaitnereffiDgnitrevnInoN
0— 0 1ETON;desaiBWOLdednEelgniSotdednEelgniSgnitrevnInoN
0— 1 1ETON;desaiBHGIHde
dnEelgniSotdednEelgniSgnitrevnInoN
0— 1ETON;desaiB0HGIHdednEelgniSotdednEelgniSgnitrevnI
0— 1ETON;desaiB1WOLdednEelgn
iSotdednEelgniSgnitrevnI
10 — — WOLdednEelgniSotdednEelgniSgnitrevnInoN
11 — — HGIHdednEelgniSotdednEelgniSgnitrevnInoN
."s
leveLdednEelgniStpeccAottupnIlaitnereffiDehtgniriW",noitcesnoitamrofnInoitacilppAehtotreferesaelP:1ETON
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
C
NI
ecnaticapaCtupnI 4Fp
C
DP
ecnaticapaCnoitapissiDrewoP
)tuptuorep( 21Fp
R
PULLUP
rotsiseRpulluPtupnI 15kΩ
R
NWODLLUP
rotsiseRnwodlluPtupnI 15kΩ
R
TUO
ecnadepmItuptuO5721Ω
TABLE 3B. OE SELECT FUNCTION TABLE
tupnIlortnoC noitarepOtuptuO
EO
0)delbasid(Z-iHniera7Q:0QstuptuO
1)delbane(evitcaera7Q:0QstuptuO
IDT™ / ICS™ LVCMOS FANOUT BUFFER 3 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDO = 3.3V±5%, TA = -40° TO 85°
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
DD 4.6V
Inputs, VI-0.5V to VDD + 0.5 V
Outputs, V
O-0.5V to VDDO + 0.5V
Package Thermal Impedance, θ
JA 70°C/W (0 lfpm)
Storage Temperature, T
STG -65°C to 150°C
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional op-
eration of product at these conditions or any conditions beyond
those listed in the DC Characteristics or AC Characteristics is not
implied. Exposure to absolute maximum rating conditions for ex-
tended periods may affect product reliability.
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
DD
egatloVylppuSeroC 531.33.3564.3V
V
ODD
egatloVylppuStuptuO 531.33.3564.3V
I
DD
tnerruCylppuSrewoP 64Am
I
ODD
tnerruCylppuStuptuO 11Am
TABLE 4B. POWER SUPPLY DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 2.5V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
DD
egatloVylppuSeroC 531.33.3564.3V
V
ODD
egatloVylppuStuptuO 573.25.2526.2V
I
DD
tnerruCylppuSrewoP 64Am
I
ODD
tnerruCylppuStuptuO 01Am
TABLE 4C. POWER SUPPLY DC CHARACTERISTICS, VDD, VDDO = 2.5V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
DD
egatloVylppuSeroC 573.25.2526.2V
V
ODD
egatloVylppuStuptuO 573.25.2526.2V
I
DD
tnerruCylppuSrewoP 34Am
I
ODD
tnerruCylppuStuptuO 01Am
IDT™ / ICS™ LVCMOS FANOUT BUFFER 4 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 4D. DC CHARACTERISTICS, VDD = VDDO = 3.3V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
HI
egatloVhgiHtupnISOMCVL2V
DD
3.0+V
V
LI
egatloVwoLtupnI KLC_SOMCVL3.0-3.1V
EO,NE_KLC8.08.0
I
NI
tnerruCtupnI V
NI
V=
DD
ro
V
NI
DNG= 003Aµ
V
HO
1ETON;egatloVhgiHtuptuOI
HO
Am42-=4.2V
V
LO
1ETON;egatloVwoLtuptuO I
LO
Am42=55.0V
I
LO
Am21=03.0V
V
PP
egatloVtupnIkaeP-ot-kaePKLCn,KLC51.03.1V
V
RMC
;egatloVedoMnommoCtupnI
3,2ETON KLCn,KLC5.0+DNGV
DD
58.0-V
05gnivirdfoelbapacstuptuO:1ETON Ω05htiwdetanimretsenilnoissimsnart ΩVot
ODD
.2/
."tiucriCtseTCAdaoLtuptuOV3.3",noitcestnemerusaeMretemaraPeeS
siKLCn,KLCrofegatlovtupnimumixameht,s
noitacilppadedneelgnisroF:2ETON V
DD
.V3.0+
sadenifedsiegatlovedomnommoC:3ETONV
HI
.
TABLE 4E. DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 2.5V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
HI
egatloVhgiHtupnISOMCVL2V
DD
3.0+V
V
LI
egatloVwoLtupnI KLC_SOMCVL3.0-3.1V
EO,NE_KLC8.0V
I
NI
tnerruCtupnI V
NI
V=
DD
ro
V
NI
DNG= 003Aµ
V
HO
1ETON;egatloVhgiHtuptuOI
HO
Am51-=8.1V
V
LO
1ETON;egatloVwoLtuptuOI
LO
Am51=6.0V
V
PP
egatloVtupnIkaeP-ot-kaePKLCn,KLC51.03.1V
V
RMC
;egatloVedoMnommoCtupnI
3,2ETON KLCn,KLC5.0+DNGV
DD
58.0-V
05gnivirdfoelbapacstuptuO:1ETON Ω05htiwdetanimretsenilnoissimsnart ΩVot
ODD
.2/
."tiucriCtseTCAdaoLtuptuOV3.3",noitcestnemerusaeMretemaraPeeS
siKLCn,KLCrofegatlovtupnimumixameht,s
noitacilppadedneelgnisroF:2ETON V
DD
.V3.0+
sadenifedsiegatlovedomnommoC:3ETONV
HI
.
IDT™ / ICS™ LVCMOS FANOUT BUFFER 5 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 4F. DC CHARACTERISTICS, VDD, VDDO = 2.5V±5%, TA = -40° TO 85°
TABLE 5A. AC CHARACTERISTICS, VDD = VDDO = 3.3V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
V
HI
egatloVhgiHtupnISOMCVL2V
DD
3.0+V
V
LI
egatloVwoLtupnI KLC_SOMCVL3.0-3.1V
EO,NE_KLC7.0V
I
NI
tnerruCtupnI V
NI
V=
DD
ro
V
NI
DNG= 003Aµ
V
HO
1ETON;egatloVhgiHtuptuOI
HO
Am51-=8.1V
V
LO
1ETON;egatloVwoLtuptuOI
LO
Am51=6.0V
V
PP
egatloVtupnIkaeP-ot-kaePKLCn,KLC51.03.1V
V
RMC
;egatloVedoMnommoCtupnI
3,2ETON KLCn,KLC5.0+DNGV
DD
58.0-V
05gnivirdfoelbapacstuptuO:1ETON Ω05htiwdetanimretsenilnoissimsnart ΩVot
ODD
.2/
."tiucriCtseTCAdaoLtuptuOV3.3",noitcestnemerusaeMretemaraPeeS
siKLCn,KLCrofegatlovtupnimumixameht,s
noitacilppadedneelgnisroF:2ETON V
DD
.V3.0+
sadenifedsiegatlovedomnommoC:3ETONV
HI
.
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
f
XAM
ycneuqerFtuptuO 053zHM
t
DP
noitagaporP
;yaleD
;KLCn,KLC
1ETON IJzHM05324sn
;KLC_SOMCVL
2ETON IJzHM05324sn
t)o(ks7,3ETON;wekStuptuO noderusaeM
V@e
gdegnisir
ODD
2/ 001sp
t)pp(ks7,4ETON;wekStraP-ot-traP noderusaeM
V@egdegnisir
ODD
2/ 1sn
t
R
t/
F
emiTllaF/esiRtuptuOV2otV8.02.01sn
cdoelcyCytuDtuptuOIJKLCn,KLC=feR,zHM0515455%
t
LZP
t,
HZP
5ETON;emiTelbanEtuptuO 5sn
t
ZLP
t,
ZHP
5ETON;emiTelbasiDtuptuO 5sn
t
S
elbanEkcolC
;emiTputeS
6ETON
otNE_KLC
KLCn,KLC 1sn
otNE_KLC
KLC_SOMCVL 0sn
t
H
elbanEkcolC
;emiTdloH
6ETON
otKLCn,KLC
NE_KLC 0sn
KLC_SOMCVL
NE_KLCot 1sn
ottniopgnissorctupnilaitnereffidehtmor
fderusaeM:1ETONV
ODD
2/.tuptuoehtfo
VmorfderusaeM:2ETON
DD
Vottupniehtfo2/
ODD
.tuptuoehtfo2/
.snoitidnocdaollauqehtiwdnaegatlovylppusemasehttastuptuoneewtebwekssadenifeD:3ETON
Vtade
rusaeM
ODD
.2/
htiwdnasegatlovylppusemasehttagnitareposecivedtnereffidnostuptuoneewtebwekssadenifeD:4ETON
Vtaderus
aemerastuptuoeht,ecivedhcaenostupnifoepytemasehtgnisU.snoitidnocdaollauqe
ODD
.2/
.noitcudorpnidetsettoN.noitaziretcarahcybdeetnaraugerasretemarapesehT:5ETON
.kcolctupniehtfoegdegni
sirehtotevitalererasemitdloHdnaputeS:6ETON
.56dradnatSCEDEJhtiwecnadroccanidenifedsiretemarapsihT:7ETO
N
IDT™ / ICS™ LVCMOS FANOUT BUFFER 6 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 5B. AC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 2.5V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
f
XAM
ycneuqerFtuptuO 053zHM
t
DP
noitagaporP
;yaleD
;KLCn,KLC
1ETON IJzHM05324sn
;KLC_SOMCVL
2ETON IJzHM05324sn
t)o(ks7,3ETON;wekStuptuO noderusaeM
V@e
gdegnisir
ODD
2/ 001sp
t)pp(ks7,4ETON;wekStraP-ot-traP noderusaeM
V@egdegnisir
ODD
2/ 1sn
t
R
t/
F
emiTllaF/esiRtuptuOV8.1otV6.02.00.1sn
cdoelcyCytuDtuptuOIJKLCn,KLC=feR,zHM0515455%
t
LZP
t,
HZP
5ETON;emiTelbanEtuptuO 5sn
t
ZLP
t,
ZHP
5ETON;emiTelbasiDtuptuO 5sn
t
S
elbanEkcolC
;emiTputeS
6ETON
otNE_KLC
KLCn,KLC 1sn
otNE_KLC
KLC_SOMCVL 0sn
t
H
elbanEkcolC
;emiTdloH
6ETON
otKLCn,KLC
NE_KLC 0sn
KLC_SOMCVL
NE_KLCot 1sn
ottniopgnissorctupnilaitnereffidehtmor
fderusaeM:1ETONV
ODD
2/.tuptuoehtfo
VmorfderusaeM:2ETON
DD
Vottupniehtfo2/
ODD
.tuptuoehtfo2/
.snoitidnocdaollauqehtiwdnaegatlovylppusemasehttastuptuoneewtebwekssadenifeD:3ETON
Vtade
rusaeM
ODD
.2/
htiwdnasegatlovylppusemasehttagnitareposecivedtnereffidnostuptuoneewtebwekssadenifeD:4ETON
Vtaderus
aemerastuptuoeht,ecivedhcaenostupnifoepytemasehtgnisU.snoitidnocdaollauqe
ODD
.2/
.noitcudorpnidetsettoN.noitaziretcarahcybdeetnaraugerasretemarapesehT:5ETON
.kcolctupniehtfoegdegni
sirehtotevitalererasemitdloHdnaputeS:6ETON
.56dradnatSCEDEJhtiwecnadroccanidenifedsiretemarapsihT:7ETO
N
IDT™ / ICS™ LVCMOS FANOUT BUFFER 7 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TABLE 5C. AC CHARACTERISTICS, VDD = VDDO = 2.5V±5%, TA = -40° TO 85°
lobmySretemaraPsnoitidnoCtseTmuminiMlacipyTmumixaMstinU
f
XAM
ycneuqerFtuptuO 053zHM
t
DP
noitagaporP
;yaleD
;KLCn,KLC
1ETON IJzHM0535.12.4sn
;KLC_SOMCVL
2ETON IJzHM0537.14.4sn
t)o(ks7,3ETON;wekStuptuO noder
usaeM
V@egdegnisir
ODD
2/ 061sp
t)pp(ks7,4ETON;wekStraP-ot-traP noderusaeM
V@egdegnisir
ODD
2/ 2sn
t
R
t/
F
emiTllaF/esiRtuptuOV8.1otV6.02.00.1sn
cdoelcyCytuDtuptuOIJKLCn,KLC=feR,zHM0510406%
t
LZP
t,
HZP
5ETON;emiTelbanEtuptuO 5sn
t
ZLP
t,
ZHP
5ETON;emiTelbasiDtuptuO 5sn
t
S
elbanEkcolC
;emiTputeS
6ETON
otNE_KLC
KLCn,KLC 1sn
otNE_KLC
KLC_SOMCVL 0sn
t
H
elbanEkcolC
;emiTdloH
6ETON
otKLCn,KLC
NE_KLC 0sn
KLC_SOMCVL
NE_KLCot 1sn
ottniopgnissorctupnilaitnereffidehtmor
fderusaeM:1ETONV
ODD
2/.tuptuoehtfo
VmorfderusaeM:2ETON
DD
Vottupniehtfo2/
ODD
.tuptuoehtfo2/
.snoitidnocdaollauqehtiwdnaegatlovylppusemasehttastuptuoneewtebwekssadenifeD:3ETON
Vtade
rusaeM
ODD
.2/
htiwdnasegatlovylppusemasehttagnitareposecivedtnereffidnostuptuoneewtebwekssadenifeD:4ETON
Vtaderus
aemerastuptuoeht,ecivedhcaenostupnifoepytemasehtgnisU.snoitidnocdaollauqe
ODD
.2/
.noitcudorpnidetsettoN.noitaziretcarahcybdeetnaraugerasretemarapesehT:5ETON
.kcolctupniehtfoegdegni
sirehtotevitalererasemitdloHdnaputeS:6ETON
.56dradnatSCEDEJhtiwecnadroccanidenifedsiretemarapsihT:7ETO
N
IDT™ / ICS™ LVCMOS FANOUT BUFFER 8 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
PARAMETER MEASUREMENT INFORMATION
V
CMR
Cross Points
V
PP
nCLK
CLK
GND
VDD
Qx
Qy
tsk(o)
V
DDO
2
V
DDO
2
Qx
Qy
PART 1
PART 2
tsk(pp)
V
DDO
2
V
DDO
2
2.5V CORE/2.5V OUTPUT LOAD AC TEST CIRCUIT
3.3V CORE/2.5V OUTPUT LOAD AC TEST CIRCUIT3.3V CORE/3.3V OUTPUT LOAD AC TEST CIRCUIT
SCOPE
Qx
LVCMOS
GND
1.65V±5%
-1.65V±5%
DIFFERENTIAL INPUT LEVEL
OUTPUT SKEW PART-TO-PART SKEW
SCOPE
Qx
LVCMOS
GND
2.05V±5%
-1.25V±5%
VDD,
VDDO
VDD
SCOPE
Qx
LVCMOS
GND
1.25V±5%
-1.25V±5%
VDD,
VDDO
VDDO
1.25V±5%
IDT™ / ICS™ LVCMOS FANOUT BUFFER 9 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
OUTPUT RISE/FALL TIME PROPAGATION DELAY
nCLK
CLK
Q0:Q7
tPD
VDDO
2
➤
➤
VDDO
2
LVCMOS_
CLK
Clock
Outputs
0.8V
2V 2V
0.8V
t
R
t
F
Clock
Outputs
0.6V
1.8V 1.8V
0.6V
t
R
t
F
VDD = VDDO = 3.3V
VDD = VDDO = 2.5V or
VDD = 3.3V, VDDO = 2.5V
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
Q0:Q7
tPERIOD
tPW
tPERIOD
odc =
V
DDO
2
x 100%
tPW
IDT™ / ICS™ LVCMOS FANOUT BUFFER 10 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
APPLICATION INFORMATION
Figure 1 shows how the differential input can be wired to accept
single ended levels. The reference voltage V_REF = VDD/2 is
generated by the bias resistors R1, R2 and C1. This bias circuit
should be located as close as possible to the input pin. The ratio
FIGURE 1. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT
of R1 and R2 might need to be adjusted to position the V_REF in
the center of the input voltage swing. For example, if the input
clock swing is only 2.5V and VDD = 3.3V, V_REF should be 1.25V
and R2/R1 = 0.609.
WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS
V_REF
R1
1K
C1
0.1u
R2
1K
Single Ended Clock Input
CLK
nCLK
VDD
INPUTS:
CLK INPUT
For applications not requiring the use of the test clock, it can be
left floating. Though not required, but for additional protection, a
1kΩ resistor can be tied from the CLK input to ground.
CLK/nCLK INPUTS
For applications not requiring the use of the differential input,
both CLK and nCLK can be left floating. Though not required, but
for additional protection, a 1kΩ resistor can be tied from CLK to
ground.
LVCMOS CONTROL PINS
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1kΩ resistor can be used.
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
OUTPUTS:
LVCMOS OUTPUTS
All unused LVCMOS output can be left floating. There should be
no trace attached.
IDT™ / ICS™ LVCMOS FANOUT BUFFER 11 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
FIGURE 2C. HIPERCLOCKS CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 2B. HIPERCLOCKS CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 2D. HIPERCLOCKS CLK/nCLK INPUT DRIVEN BY
3.3V LVDS DRIVER
3.3V
R1
50
R3
50
Zo = 50 Ohm
LVPECL
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
3.3V
Input
R2
50
Zo = 50 Ohm
Input
HiPerClockS
CLK
nCLK
3.3V
R3
125
R2
84
Zo = 50 Ohm
3.3V
R4
125
LVPECL
R1
84
3.3V
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL
and other differential signals. Both VSWING and VOH must meet the
VPP and VCMR input requirements. Figures 2A to 2E show interface
examples for the HiPerClockS CLK/nCLK input driven by the most
common driver types. The input interfaces suggested here are
FIGURE 2A. HIPERCLOCKS CLK/nCLK INPUT DRIVEN BY
ICS HIPERCLOCKS LVHSTL DRIVER
examples only. Please consult with the vendor of the driver
component to confirm the driver termination requirements. For
example in Figure 2A, the input termination applies for ICS
HiPerClockS LVHSTL drivers. If you are using an LVHSTL driver
from another vendor, use their termination recommendation.
1.8V
R2
50
Input
LVHSTL Driver
ICS
HiPerClockS
R1
50
LVHSTL
3.3V
Zo = 50 Ohm
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
FIGURE 2E. HIPERCLOCKS CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER WITH AC COUPLE
Zo = 50 Ohm
R3
125
HiPerClockS
CLK
nCLK
3.3V
R5
100 - 200
3.3V
R2
84
3.3V
R6
100 - 200
Input
R5,R6 locate near the driver pin.
Zo = 50 Ohm
R1
84
R4
125
C2
LVPECL C1
Zo = 50 Ohm
R1
100
3.3V
LVDS_Driv er
Zo = 50 Ohm
Receiv er
CLK
nCLK
3.3V
IDT™ / ICS™ LVCMOS FANOUT BUFFER 12 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
SCHEMATIC EXAMPLE
Figure 3 shows a schematic example of the ICS8308I. In this
example, the LVCMOS_CLK input is selected. The decoupling
FIGURE 3. ICS8308I LVPECL BUFFER SCHEMATIC EXAMPLE
C4
0.1u
(U1,9)
R1 43
VDD
Zo = 50 Ohm
Zo = 50 Ohm
(U1,16)
R10
1K
R11 43
C2
0.1u
C3
0.1u
VDD
(U1,20)
U1
ICS8308I
1
2
3
4
5
6
7
8
9
10
11
12 13
14
15
16
17
18
19
20
21
22
23
24
Q0
GND
CLK_SEL
LVCMOS_CLK
CLK
nCLK
CLK_EN
OE
VDD
GND
Q1
VDDO Q7
GND
Q6
VDDO
Q5
GND
Q4
VDDO
Q3
GND
Q2
VDDO
VDD=3.3V
R9
1K
(U1,12)
R8 43
Ro ~ 7 Ohm
3.3V_LVCMOS
3.3V LVCMOS/LVTTL
C5
0.1u
R12
1K
VDD
(U1,24)
Zo = 50 Ohm
VDD
VDD
3.3V LVCMOS/LVTTL
C1
0.1u
capacitors should be physically located near the power pin.
RELIABILITY INFORMATION
TRANSISTOR COUNT
The transistor count for ICS8308I is: 1040
TABLE 6. θ
JAVS. AIR FLOW TABLE FOR 24 LEAD TSSOP
θθ
θθ
θJA by Velocity (Linear Feet per Minute)
0 200 500
Multi-Layer PCB, JEDEC Standard Test Boards 70°C/W 63°C/W 60°C/W
IDT™ / ICS™ LVCMOS FANOUT BUFFER 13 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
PACKAGE OUTLINE - G SUFFIX FOR 24 LEAD TSSOP
TABLE 7. PACKAGE DIMENSIONS
REFERENCE DOCUMENT: JEDEC PUBLICATION 95, MO-153
LOBMYS sretemilliM
muminiMmumixaM
N42
A--02.1
1A50.051.0
2A08.050.1
b91.003.0
c90.002.0
D07.709.7
ECISAB04.6
1E03.405.4
eCISAB56.0
L5
4.057.0
α°0°8
aaa--01.0
IDT™ / ICS™ LVCMOS FANOUT BUFFER 14 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology, Incorporated (IDT) assumes no responsibility for either its use or for
infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial and
industrial applications. Any other applications such as those requiring high reliability or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT
reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments.
TABLE 8. ORDERING INFORMATION
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IGA8038SCIIGA8038SCIPOSSTdaeL42ebutC°58otC°04-
TIGA8
038SCIIGA8038SCIPOSSTdaeL42leer&epatC°58otC°04-
FLIGA8038SCIFLIGA8038SCIPOSST"eerF-daeL"daeL42ebutC°58otC°04-
T
FLIGA8038SCIFLIGA8038SCIPOSST"eerF-daeL"daeL42leer&epatC°58otC°04-
.tnailpmocSHoReradnanotiarugifnoceerF-b
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IDT™ / ICS™ LVCMOS FANOUT BUFFER 15 ICS8308AGI REV. B OCTOBER 16, 2007
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
TEEHSYROTSIHNOISIVER
veRelbaTegaPegnahCfonoitpircseDetaD
A11tuoyaLcitamehcSdeddA 40/61/4
B
B4T
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1
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4
6
8
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40/02/01
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mrofniegakcapdetcerroc-tnemngissAniP 60/4/8
BB3T2 .elbaTnoitcnuFtceleSEOdeddA 70/61/01
Innovate with IDT and accelerate your future networks. Contact:
www.IDT.com
For Sales
800-345-7015
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Integrated Device Technology, Inc.
6024 Silver Creek Valley Road
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Integrated Device Technology
Singapore (1997) Pte. Ltd.
Reg. No. 199707558G
435 Orchard Road
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Singapore 238877
+65 6 887 5505
Europe
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321 Kingston Road
Leatherhead, Surrey
KT22 7TU
England
+44 (0) 1372 363 339
Fax: +44 (0) 1372 378851
© 2007 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT, the IDT logo, ICS and HiPerClockS are trademarks
of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be
trademarks or registered trademarks used to identify products or services of their respective owners.
Printed in USA
ICS8308I
LOW SKEW, 1-TO-8 DIFFERENTIAL/LVCMOS-TO-LVCMOS FANOUT BUFFER
