Hi Support Team!
Just a question about the 853S011BMILF device. This is a distribution/buffer chip meant to interface to other PECL devices. This device is going to be used as a distribution IC for clocking the AD9251 (ADI 14 bit ADC). The source oscillator also has a PECL output. The datasheet for the AD9251 is linked here (see page 25, Fig 52):
This shows that in their scheme to use a couple 240 ohm shunt resistors and coupling caps into the ADC inputs. Would this be acceptable in interfacing the 853S011 with the AD9251? Typically when interfacing PECL devices I would see either bias resistors or a resistors with an equivalent thevenin source but this is a little different. Your datasheet calls out what I have typically seen.
I want to trust ADI's datasheet but they probably have not tried every device out there so this is what I am asking here.
You are correct, the ADI recommendation applies for the ADC which probably has its own internal dc-bias. For the 853S011B, we recommend adding a dc-bias after the capacitors:
See excerpt below from Renesas…
See excerpt below from Renesas AN-952.
R1 and R2 can be 240ohms, as recommended by the ADI datasheet.
R3/R4/R5/R6 create the correct dc-bias while also terminating the transmission line with 50ohm loading.
Thanks for the very quick response. This is what I am looking for! I have accepted your answer.