ACS8944 Semtech Corporation, ACS8944 Datasheet - Page 10

• Manufacturer Part Number: ACS8944
• Description: Jitter Attenuating, Multiplying Phase Locked Loop for Oc-12/stm-4
• Manufacturer: Semtech Corporation

Application Schematic of Combined ACS8525 and ACS8944
Figure 11 shows the circuit diagram of the clock solution
part of an application combining an ACS8525 line card
part with a dejittering ACS8944. A full design would
require a microcontroller for advanced control and
ACS8525 device setup; an ACS8525 line card protection
Figure 11 Line Card Clock Source Example Schematic ACS8525 and ACS8944
Revision 3/November 2006 © Semtech Corp.
ADVANCED COMMUNICATIONS
Note...For optimal performance use a Low Voltage Dropout (LDO) Regulator to supply VDDA2
uProc interface for
control, monitoring or
setup
RESET
CONTROLLER
VDDA
VDDA
100nF
C8
100nF
C9
VDDA
100nF
AGND
AGND
C11
12.8MHz
IQXO-71
For Loop Filter
Components, see
Table 6 and Table 7.
AGND
AGND
R10
1M
AGND
X1
DOWNSTREAM
DEVICE,
LVPECL INPUTS
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
100nF
C6
TCK
TDO
TDI
SDO
DGND6
VDD7
IC
O2
VA3+
AGND4
IC1
IC2
IC3
IC4
IC5
SONSDHB
AGND
100nF
C12
AGND3
VDDA
R16
1M
VDDA
10R
R9
OUT1N
OUT1P
LOOP FILTER
COMPONENTS
ACS8525
C29
100nF
AGND
R6
82
IC1
AGND3
C13
100nF
AGND2
R4
130
VDDA2
100nF
C15
R7
82
C25
100pF
AGND2
AGND
130
R5
C2
C1
C3
C4
VDDA2
VDDA
10R
R8
VDD_DIFF 22
GND_DIFF 21
SEC2NEG 26
SEC1NEG 24
SEC2POS 25
SEC1POS 23
MFrSync 18
R1
R2
DGND4 31
VDD5V 27
O1NEG 20
O1POS 19
SYNC1 28
FrSync 17
VDD1 32
SEC2 30
SEC1 29
AGND
C24
10nF
C14
VDDA
100nF
AGND
C28 100pF
C26 100uF
C27 10nF
SEC2
AGND2
FINAL
Input Clocks
Page 10
VDDA
VDDA2
AGND2
VDDA
C7
VDDA2
R15 ZERO
OHM LINK
100nF
10nF
C16
device containing DPLLs/APLLs, synthesizers and
monitors and the ACS8944 for jitter reduction. Just the
parts relevant to the clock production are shown here, i.e.
the ACS8525 and ACS8944.
C10
100nF
AGND
AGND2
IC3
VDDOSC
VSSOSC
RESETB
IC4
IC5
VDDP2
NC16
NC17
OP_FSEL
NC18
NC19
100pF
VDDA2
AGND
C17
SEC1
AGND
C22
100pF
C23
10nF
VDDA2
AGND2
C19
100pF
C18
10nF
R11
82
R12
82
AGND2
R13
130
R14
130
C21
100pF
VDDA2
C20
10nF
CFG_OUT3
CFG_OUT2
CFG_OUT1
CFG_OUT0
VDDA
LOCKB
NC11
NC10
EXT3
EXT2
EXT1
ACS8944 JAM PLL
IC2
IC1
AGND2
C5
220nF
F8944D_021ExSchematic_08
R3
470K
LOCKB
AGND2
J1
DATASHEET
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