Diodes Incorporated

Frequently Asked Questions

Search our knowledge base of commonly asked questions to find answers to your questions about our products and services.

Results for PCI Express® 3.0

Can the un-used clock IC outputs be left open?

Yes, the clock ICs’ outputs can be just left open if they are not used. In this way can save the un-used buffer output drawing power without driving anything.

What can pull-up/down value be on PCB for Clock IC inputs?

It is recommended to use 4.7k for pull-up and 1k for pull-down even though Clock IC has internal pull-up/down as high reliability design guide, include un-used inputs pins.

What is FCP XO product?

FCP is Frequency Control Product. They include crystals, crystal oscillators (XO), voltage control oscillators (VCXO), and TCXO. XO has IC and crystal integrated together as a component for quality easy use in system designs. For more product information, please visit company website: https://www.diodes.com/products/connectivity-and-timing/crystal-and-crystal-oscillator/


What is LVPECL clock and its termination?

LVPECL is Low Voltage Positive (supply) Emitter Couple Logic. Its voltage level is around 2V+/-400mV and the most use termination is 150 ohm pull-down at output pin and AC or DC coupling to an equivalent 100 ohm across pair at RX ASIC side. Check ASIC datasheet  to prevent double termination.