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AS1153/55

Data Sheet - A p p l i c a t i o n s

9 Applications

Figure 19. Typical Application Circuit

Power-Supply Bypassing

Differential Traces

Input trace characteristics can adversely affect the performance of the AS1155/58 and AS1153/57.

!

Use controlled-impedance PC board traces to match the cable characteristic impedance. The termination resistor

must also be matched to this characteristic impedance.

!

Eliminate reflections and ensure that noise couples as common mode by running differential traces close together.

!

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.

Cables and Connectors

Supported transmission media include printed circuit board traces, backplanes, and cables.

Table 5. Function Table

Input

Output

INx+

INx-

OUTx

≥ +100mV

H

≤ +100mV

L

AS1153/55 – Open, undriven short, or undriven

100

Ω parallel termination

H

AS1157/58 – Open or undriven short

LVDS

Signals

107

Ω

LVTTL/LVCMOS

Data Inputs

LVTTL/LVCMOS

Data Outputs

100

Ω Shielded Twisted Cable or Microstrip PC Board Traces

Tx

Rx

AS1158

Single LVDS Receiver

AS1152

0.1µF

0.001µF

+3.3V

0.1µF

0.001µF

+3.3V