AS1152
austriamicrosystems
Data Sheet
Power-Supply Bypassing
9 Applications
Table 5. Function Table
Enable Pins
Input
Output
EN
H
ENn
INx+
INx-
L
OUTx
L or Open
L or Open
L
H
H
L
H
H
Other Combinations of Enable Pin Settings
Don’t Care
Z
Z
Figure 17. Typical Application Circuit
LVDS
Signals
Rx
Tx
Tx
107Ω
Rx
Rx
107Ω
107Ω
107Ω
LVTTL/LVCMOS
Data Inputs
LVTTL/LVCMOS
Data Outputs
Tx
Rx
Tx
AS1151
Quad LVDS Receiver
AS1152
100Ω Shielded Twisted Cable or Microstrip PC Board Traces
Power-Supply Bypassing
To bypass VCC, use high-frequency surface-mount ceramic 0.1µF and 0.001µF capacitors in parallel as close to the
device as possible, with the smaller valued capacitor closest to pin VCC.
Differential Traces
Input trace characteristics can adversely affect the performance of the AS1152.
!
Use controlled-impedance PC board traces to match the cable characteristic impedance. The termination resistor is
also matched to this characteristic impedance.
!
Eliminate reflections and ensure that noise couples as common mode by running the differential traces near each
other.
!
Reduce skew by using matched trace lengths. Tight skew control is required to minimize emissions and proper data
recovery of the devices.
!
Route each channel’s differential signals very close to each other for optimal cancellation of their respective exter-
nal magnetic fields. Use a constant distance between the differential traces to avoid irregularities in differential
impedance.
!
Avoid 90° turns (use two 45° turns).
!
Minimize the number of vias to further prevent impedance irregularities.
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