Differential Traces

Output trace characteristics affect the performance of

the MAX9110/MAX9112. Use controlled impedance

traces to match trace impedance to both transmission

medium impedance and termination resistor. Eliminate

reflections and ensure that noise couples as common

mode by running the differential traces close together.

Reduce skew by matching the electrical length of the

traces. Excessive skew can result in a degradation of

magnetic field cancellation.

Maintain the distance between the differential traces to

avoid discontinuities in impedance. Avoid 90° turns and

minimize the number of vias to further prevent imped-

ance discontinuities.

Cables and Connectors

Transmission media should have a differential charac-

teristic impedance of about 100

Ω. Use cables and con-

nectors that have matched impedance to minimize

impedance discontinuities.

Avoid the use of unbalanced cables, such as ribbon or

simple coaxial cable. Balanced cables, such as twisted

pair, offer superior signal quality and tend to generate

less EMI due to canceling effects. Balanced cables

tend to pick up noise as common mode, which is

rejected by the LVDS receiver.

Termination

Termination resistors should match the differential char-

acteristic impedance of the transmission line. Because

the MAX9110/MAX9112 are current-steering devices,

an output voltage will not be generated without a termi-

nation resistor. Output voltage levels are dependent

upon the termination resistor value. Resistance values

may range between 75

Ω and 150Ω.

Minimize the distance between the termination resistor

and receiver inputs. Use a single 1% to 2% surface-

mount resistor across the receiver inputs.

Board Layout

For LVDS applications, a four-layer PC board that pro-

vides separate power, ground, LVDS signals, and input

signals is recommended. Isolate the input and LVDS sig-

nals from each other to prevent coupling. Separate the

input and LVDS signal planes with the power and ground

planes for best results.

Single/Dual LVDS Line Drivers with

Ultra-Low Pulse Skew in SOT23

_______________________________________________________________________________________

7

MAX9110 TRANSISTOR COUNT: 765

MAX9112 TRANSISTOR COUNT: 765

PROCESS: CMOS

Chip Information

Ω

0.001

µF0.1µF

+3.3V

DIN_

MAX9110

MAX9112

MAX9111

MAX9113

OUT_

LVDS

0.001

µF0.1µF

+3.3V

RECEIVER

DRIVER

Typical Operating Circuit