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Design >> High-Speed I/O Design >> the DC coupling between the CML-PECL
https://designers-guide.org/forum/YaBB.pl?num=1147747766

Message started by john_xu on May 15^th, 2006, 7:49pm

Title: the DC coupling between the CML-PECL
Post by john_xu on May 15^th, 2006, 7:49pm

Hi,
We are developing a chip which we expect to replace some commercial ones. The commercial one is Bicmos in which the output is PECL buffer. We use the CMOS process to replace it, so we can only use it with CML output buffer. If the applications is AC coupling, I think it is OK for the CML-PECL connection. But if the applications need DC coupling, we know it is difficult for the CML-PECL connection considering the decrepancy of the two buffers.

Can I implement the PECL with two external bipolar transistors, i.e., on chip CML buffer+external bipolar transistors to implement the PECL output? Is any price, performance, etc.. concerns for the customers?

Thanks in advance for the comments

Title: Re: the DC coupling between the CML-PECL
Post by ywguo on May 15^th, 2006, 10:44pm

John,

PECL is already a standard interface. Of course a PECL transmitter/receiver can be made of MOS transistors. There are some papers in IEEE explorer. You'd better search them in IEEE database.

Best regards,
Yawei