High-Speed Comparator

[chanchg]

I have to design a fully-differential high speed comparator with following specs

1. CMIR 1.2V to 2.5V
2. Overdrive Voltage 0.3V
3. Propagation Delay of 0.6ns.
4. Less than 1ns rise and fall time when terminated with 300Ohm at 5V.
5. Input signal freq varies from Dc to 220Mhz

Process is 0.35u CMOS

Can any one suggest the topology and design method for above comparator?

Regards

 

[Vamsi Mocherla]

Since this is high speed, you can go for a preamp and latch type of comparator.

 

[hung_wai_ming@hotmail.com]

(3) Propagation Delay of 0.6ns.

This spec I don't think can be achievable
Think of a simple inverter in 0.35um, can u archieve a comparator comparable to an simple inverter?

Maybe the spec is wrong

 

[rajanarender_suram]

0.6ns Prop delay, @300ohm load and 1ns Tr/Tf on 0.35um Cmos ..hmm i too dont think its acheivable

 

[MikeR]

What resolution you need ? You can use double feedback latch for your specs.

 

[rania_hassan]

I think you can use clocked amplifier especially if it's a part of receiver system
Rania