avt
Member level 5
cmos to cml
Hi,
I need help - I have a (differential) cml buffer which drives the output driver stage of a lvds TX driver. Now I would like to have a stage before the ml buffer which converts the data-signal which has cmos-logic-level and is single-ended to the differential potential that is needed by the cml buffer.
I figured out that it's not only the task to generate an inverted signal - but I have to have also a "limited" voltage swing at the gates/inputs of the diffpair of the cml buffer because otherwise I will have latency due to capacitor loading/undloading when the input devices go from linear region into saturation or from subthreshold to saturation - as high or very low input voltages will drive the diffpair into subthrashold or into the linear region of course ...
so for my 3.3V design I will need something that is more or less an inverter (chain) which has limited out voltage swing - let's say 1V to 2.3V and has the ability to have anyway furtheron very fast ristimes ...
If someone hasinformation how to build such a converter in a clever way - let me know - I would realy appreciate it ...
Hi,
I need help - I have a (differential) cml buffer which drives the output driver stage of a lvds TX driver. Now I would like to have a stage before the ml buffer which converts the data-signal which has cmos-logic-level and is single-ended to the differential potential that is needed by the cml buffer.
I figured out that it's not only the task to generate an inverted signal - but I have to have also a "limited" voltage swing at the gates/inputs of the diffpair of the cml buffer because otherwise I will have latency due to capacitor loading/undloading when the input devices go from linear region into saturation or from subthreshold to saturation - as high or very low input voltages will drive the diffpair into subthrashold or into the linear region of course ...
so for my 3.3V design I will need something that is more or less an inverter (chain) which has limited out voltage swing - let's say 1V to 2.3V and has the ability to have anyway furtheron very fast ristimes ...
If someone hasinformation how to build such a converter in a clever way - let me know - I would realy appreciate it ...