SERDES differential to single ended

Hi,

You should have posted this question in the Clock and Timing section because this group supports the AD9528.

You want to transport the clocks in a differential way because of its noise rejection properties.

The LTC6955 accepts inputs that have an input common mode voltage between 1.6V and 2.7V and an input power level between 0.25Vp-p and 1.6Vp-p.

This input common mode voltage seems higher than what the AD9528 can output in HSTL mode (0.88V to 0.94V) or LVDS 3.5mA mode (1.15V to 1.35V). So you cannot connect the AD9528 outputs to the lTC6955 in dc coupled mode.

You could use the AD9528 LVDS 3.5mA outputs (690mVp-p to 780mVp-p) to connect them differentially in ac coupled way to the LTC6955.

But my understanding is the SYSREF clocks should be transported in dc coupled ways, not ac coupled. So, if possible, I recommend selecting chips that can be connected in a dc coupled way for SYSREF transport.

Petre

Hi,

You should have posted this question in the Clock and Timing section because this group supports the AD9528.

You want to transport the clocks in a differential way because of its noise rejection properties.

The LTC6955 accepts inputs that have an input common mode voltage between 1.6V and 2.7V and an input power level between 0.25Vp-p and 1.6Vp-p.

This input common mode voltage seems higher than what the AD9528 can output in HSTL mode (0.88V to 0.94V) or LVDS 3.5mA mode (1.15V to 1.35V). So you cannot connect the AD9528 outputs to the lTC6955 in dc coupled mode.

You could use the AD9528 LVDS 3.5mA outputs (690mVp-p to 780mVp-p) to connect them differentially in ac coupled way to the LTC6955.

But my understanding is the SYSREF clocks should be transported in dc coupled ways, not ac coupled. So, if possible, I recommend selecting chips that can be connected in a dc coupled way for SYSREF transport.

Petre