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.

Low-Jitter, Precision Clock Generator

with Two Outputs

8

_______________________________________________________________________________________

MAX3622

QAC_OE

QB_OE

QA_C

X_OUT

X_IN

GNDO_A

GND

10.5

Ω

0.01

μF

0.1

μF

36

Ω

Ω

ASIC

125MHz

QB

50

Ω

Ω

QB

Ω

ASIC

50

Ω

156.25MHz

10

μF

0.1

μF

25MHz

33pF

27pF

0.01

μF

0.1

μF

+3.3V

±5%

Typical Application Circuit