high resolution comparator architecture

[nijMcnij]

high resolution comparator

hello all,

i am designing a 10 bit ADC, and i need an architecture for a comparator that can achieve a resolution of 1.6mV.

any ideas, papers, books, references?

many thanks

 

[bastos4321]

comparator architecture

hello all,

i am designing a 10 bit ADC, and i need an architecture for a comparator that can achieve a resolution of 1.6mV.

any ideas, papers, books, references?

many thanks

Use a low-gain amplifier folowed by a latch comparator, and output offset compensation.

Bastos

 

[nijMcnij]

thank u Bastos for the advice,

but i want to add that speed is not an issue, the primary concern is high resolution,

also i would really like to make things simple, so is there a way to do this without using offset cancellation?

and can u recommend a reference for designing such a comparator

thanks

 

[bastos4321]

thank u Bastos for the advice,

but i want to add that speed is not an issue, the primary concern is high resolution,

also i would really like to make things simple, so is there a way to do this without using offset cancellation?

and can u recommend a reference for designing such a comparator

thanks

Well in that case you just can play with devices area to control the offset, this means that you will need large devices to get that offset at 3 sigma. Large devices gives you lower speed and more power. You can try the Sansen comparator for example and play with the gm and area of devices to achive that offset.

G. Yin, F. Eynde, W. Sansen, “A high-speed CMOS comparator with 8-b resolution,” IEEE J. Solid-State Circuits, vol. 27, pp. 208-211, Feb. 1992.

Bastos

PS: What is the application of this comparator in the ADC. Usualy the comparators in a pipeline need a much larger offset due to the error correction logic.

 

[nijMcnij]

thank u bastos,

the comparator will be used for a 10bit 2KSPS charge redistribution SAR ADC.

as u can see, speed is not an issue, what matters is resolution first and foremost.

do u think i can get a 10 bit resolution with this sansen comparator?

the comparator should have a gain of around 67dB.

many thanks