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IDT / ICS 3.3V LVPECL FREQUENCY SYNTHESIZER
11
ICS843004AG-02 REV A JULY 30, 2007
ICS843004-02
CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
LAYOUT GUIDELINE
Figure 5 shows an example of ICS843004-02 application
schematic. In this example, the device is operated at
V
CC = 3.3V. The decoupling capacitor should be located as close
as possible to the power pin. Both input options are shown.
The device can either be driven using a quartz crystal or a
To Logic
Input
pins
VCC
RD2
1K
C3
0.1uF
R5
50
Ro ~ 7 Ohm
Q1
Driv er_LVCMOS
C2
33pF
VCC
RD1
Not Install
MR
F_SEL2
Zo = 50 Ohm
+
-
C3
10uF
RU1
1K
VCCO
X1
19.44MHz
To Logic
Input
pins
Zo = 50 Ohm
C1
0.1uF
VCCO
Set Logic
Input to
'1'
F_SEL1
F_SEL0
U4
843004-02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
nQ
1
Q1
V
CCO
Q0
nQ
0
MR
nP
LL_S
E
L
NC
VC
C
A
F_
S
E
L
0
VC
C
F_
S
E
L
1
XT
AL
_
O
U
T
XT
AL
_
IN
VE
E
TE
S
T_
C
L
K
nX
T
A
L_
S
E
L
F_
S
E
L
2
nQ
3
Q3
V
CCO
Q2
nQ
2
(U1-3)
R7
50
+
-
C2
0.1uF
Logic Control Input Examples
Zo = 50 Ohm
R8
43
R2
10
R5
133
VCCO=3.3V
Optional
Y-Termination
nPLL_SEL
C4
0.01u
R4
82.5
R6
82.5
R6
50
VDD
C1
27pF
3.3V
VCCA
nXTAL_SEL
(U1-12)
VCC
Set Logic
Input to
'0'
R3
133
VCC
Zo = 50 Ohm
VCC=3.3V
18pF
RU2
Not Install
(U1-22)
3.3V LVCMOS signal. For the LVPECL output drivers, only two
termination examples are shown in this schematic. Additional
termination approaches are shown in the LVPECL Termination
Application Note.
FIGURE 5. ICS843004-02 SCHEMATIC EXAMPLE