SERDESUR-43USB/NOPB National Semiconductor, SERDESUR-43USB/NOPB Datasheet - Page 21

• Manufacturer Part Number: SERDESUR-43USB/NOPB
• Description: BOARD EVAL DS90UR124,DS90UR241
• Manufacturer: National Semiconductor

Specifications of SERDESUR-43USB/NOPB

• Main Purpose: Interface, Serializer, Deserializer (SERDES)
• Utilized Ic / Part: DS90UR241, DS90UR124
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: SERDESUR-43USB

If the demo boards are not performing properly, use the following as a guide for quick
solutions to potential problems. If the problem persists, please contact the local Sales
Representative for assistance.
QUICK CHECKS:
1. Check that Power and Ground are connected to both Tx AND Rx boards.
2. Check the supply voltage (typical 3.3V) and also current draw with both Tx and Rx
3. Verify input clock and input data signals meet requirements for VILmin, VILmax,
4. Check that the Jumpers and Switches are set correctly.
5. Check that the cable is properly connected.
TROUBLESHOOTING CHART
Problem…
There is only the output clock.
There is no output data.
No output data and clock.
Power, ground, input data and
input clock are connected
correctly, but no outputs.
The devices are pulling more
than 1A of current.
After powering up the demo
boards, the power supply
reads less than 3V when it is
set to 3.3V.
Troubleshooting
boards. The Serializer board should draw about 55-65mA with clock and all data
bits switching at 43MHz, (R
75-85mA with clock and all data bits switching at 43MHz, (minimum ROUT loading).
VIHmin, VIHmax, tset, thold), also verify that data is strobed on the selected
rising/falling (RFB pin) edge of the clock.
SERDES Evaluation Kit DS90UR241/124 USB Version 0.1 User Manual
National Semiconductor Corporation
PRE
=9KΩ). The De-serializer board should draw about
Solution…
Make sure the data is applied to the correct input pin.
Make sure data is valid at the input.
Make sure Power is on. Input data and clock are
active and connected correctly.
Make sure that the cable is secured to both demo
boards.
Check the Power Down pins of both Serializer and
De-serializer boards to make sure that the devices
are enabled (/PD=Vcc) for operation. Also check
DEN on the Serializer board and REN on the
Deserializer board is set HIGH.
Check for shorts in the cables connecting the TX and
RX boards.
Use a larger power supply that will provide enough
current for the demo boards, a 500mA minimum
power supply is recommended.
Date: 5/8/2008
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