DS90C241QVS National Semiconductor, DS90C241QVS Datasheet - Page 19

• Manufacturer Part Number: DS90C241QVS
• Manufacturer: National Semiconductor

Specifications of DS90C241QVS

• Number Of Elements: 1
• Number Of Receivers: 24
• Number Of Drivers: 1
• Input Type: CMOS/TTL
• Operating Supply Voltage (typ): 3.3V
• Output Type: Serializer
• Differential Output Voltage: 1.2V
• Operating Temp Range: -40C to 105C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 48
• Package Type: TQFP
• Lead Free Status / Rohs Status: Not Compliant

lines help to ensure that coupled noise will appear as com-
mon-mode and thus is rejected by the receivers. The tightly
coupled lines will also radiate less.
Termination of the LVDS interconnect is required. For point-
to-point applications, termination should be located at both
ends of the devices. Nominal value is 100 Ohms to match the
line’s differential impedance. Place the resistor as close to the
transmitter DOUT± outputs and receiver RIN± inputs as pos-
sible to minimize the resulting stub between the termination
resistor and device.
LVDS INTERCONNECT GUIDELINES
See AN-1108 and AN-905 for full details.
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Use 100Ω coupled differential pairs
Use the S/2S/3S rule in spacings
FIGURE 17. AC Coupled Application
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Additional general guidance can be found in the LVDS
Owner’s Manual - available in PDF format from the National
web site at: www.national.com/lvds
—S = space between the pair
—2S = space between pairs
—3S = space to LVCMOS/LVTTL signal
Minimize the number of VIA
Use differential connectors when operating above
500Mbps line speed
Maintain balance of the traces
Minimize skew within the pair
Terminate as close to the TX outputs and RX inputs as
possible
20171918
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