THS6222: Damage at parallel connection

Hello David,

May I ask if this is a hypothetical question or a debugging (something has been damaged already) question?

We have customers actively using our THS62x2 line driver family in parallel configurations.   I can assist your customer on this topic.

Would you need to communicate offline with me to share customer details and circuit schematics?

In general, one issue can be if there is an out-of-phase or misalignment on the driving capabilities of the line drivers.  The circuit design needs to consider the CFB (current feedback) architecture of the parts as well as the need to have matched components to prevent offsets.

I can help more once I know the customer system and circuit needs.  It is also important to respect the common mode voltage requirements of the THS6222.

Best,

Alec

Hi Alec,

Thanks for your support.

This is not debug.

Customer would like to use it in parallel configuration and asking if there is any issue in it.

After design the schematic and layout, I'll share it.

Thanks.

Hello David,

A key consideration is proper selection of the load resistor to both THS6222 outputs.  The system would have issue and/or damage if one device was driving more load than the other.

I am glad to help review a design once it is available.  I will look and see if I can make a recommendation, but it may be easier to help review than to give advice prior to a schematic draft.

For PCB layout, there needs to be consideration for PCB thermals and power planes, as THS6222 has thermal pad with connection to negative supply rail.  Please advise your customer to follow best practices for high speed PCB layout, as well as good power supply connections and traces (including decoupling and bypass capacitors).  When we see issues withe line-driver designs, the issues are often with allowing transients or high currents to occur and damage the line-driver.  

Best,

Alec