Rainbow Electronics MAX3622 - Manual (Page 8)

Layout Considerations
The inputs and outputs are critical paths for the
MAX3622, and care should be taken to minimize dis-
continuities on these transmission lines. Here are some
suggestions for maximizing the MAX3622’s perfor-
mance:
• An uninterrupted ground plane should be posi-
tioned beneath the clock I/Os.
• Supply and ground pin vias should be placed
close to the IC and the input/output interfaces to
allow a return current path to the MAX3622 and the
receive devices.
• Supply decoupling capacitors should be placed
close to the MAX3622 supply pins.
• Maintain 100
Ω differential (or 50Ω single-ended)
transmission line impedance out of the MAX3622.
• Use good high-frequency layout techniques and a
multilayer board with an uninterrupted ground
plane to minimize EMI and crosstalk.
Refer to the MAX3622 Evaluation Kit for more information. MAX3622
Low-Jitter, Precision Clock Generator
with Two Outputs
8 _______________________________________________________________________________________
MAX3622
V
CCA
QAC_OE
QB_OE
QA_C
X_OUT X_IN GNDO_A GND
V
CC
V
CCO_B
V
DDO_A
10.5 Ω
0.01 μF
0.1 μF
V
CC
36 Ω
Z
0
= 50 Ω ASIC
125MHz
QB
50 Ω
Z 0 = 50 Ω
QB Z
0
= 50 Ω
ASIC
50 Ω
156.25MHz
(V CC - 2V)
10 μF
0.1 μF
25MHz
(C
L
= 18pF)
33pF 27pF
0.01 μF 0.1 μF
+3.3V ±5%
V
CC
Typical Application Circuit