Техническая Спецификация для Linear Technology DC890B - USB Data Acquisition Controller, for PScope Evaluation Kits (up to 250Mbps, CMOS/LVDS) DC890B DC890B

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dc890bf

DEMO MANUAL DC890B

Problem: DC890B is plugged in, but PScope software still 
does not recognize DC890B board.

Solution: Assuming that the USB hardware in your com-
puter is operational (try verifying an operational USB port 
with another USB device such as a USB memory stick, 
printer or scanner if available.), the likely cause is improper 
installation of the USB drivers, which results in Windows 
recognizing the DC890B as an unknown device. If this is 
the case, the problem can be corrected by the following 
procedure:

1) Unplug the DC890B board from the USB port.

2) Reinstall the PScope software. Carefully following the  

on-screen instructions. This may require a reboot of 
your computer. The  on-screen instructions will inform 
you if that is the case.

3) If the problem persists, please choose contact software 

support from the tools menu for assistance from LTC 
staff.

Problem: Demonstration circuit software loads properly, 
but will not run or gives device not accessible errors.

Solution: Verify the demonstration circuit is properly 
powered up and a correct (signal level and frequency) 
conversion clock is applied. (The DC890B can operate 
from the USB port power in CMOS mode but will not 
load the FPGA with the LVDS code unless external power 
is detected.) Set the correct sample rate for the applied 
conversion clock as PScope software uses the sample 
size and rate to determine the watch dog time out period 

to reset the DC890B if the USB bus should hang. Refer 
to the appropriate demonstration circuit quick start guide 
for details.

Problem: Collected data samples look like noise or appear 
corrupted.

Solution: Make sure the proper device has been selected 
in the PScope software, the factory jumper settings are 
present and for LVDS output demo boards, external power 
is applied to the DC890B otherwise the captured data will 
not be properly interpreted.

Problem: PScope reports it cannot reset the DC890B. 

Solution: Make sure either a powered USB port is used 
or external power is supplied. DO NOT USE A USB CABLE 
LONGER THAN 2 METERS. The time delay of a longer USB 
cable may result in the DC890B intercepting the reset.

Problem: USB Bus appears to be hung.

Solution: As the DC890B is used in a lab environment 
where power may be inappropriately sequenced, cables 
unintentionally disconnected etc, some users have re-
portedly had their USB bus hang. This condition is easily 
rectified by right clicking properties under my computer 

⇒ Hardware ⇒ Device Manager ⇒ and then right clicking 
on the appropriate USB bus controller and again selecting 
properties. The device status generally reports that it is 
working properly. Select the advanced tab. You will notice 
a refresh button. Device manager has queried the port, 
and as a result, reset the bus.