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16-bit CD-Audio successive approximation ADC ?

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skjsun

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is this actually doable in 0.35 um or 0.5 um CMOS nowadays without calibration or trimming ? i do not want to do a sigma-delta ADC for this "threshold" resolution (16 bits, cause it's high, but not too high to keep successive approximation out of choice), can anyone give me suggestions ?
 

Hey try and design using an integrating architecture. I would suggest a dual slope or a quad slope architecture in order to achieve the required resolution. There are designs using integrating architecture and achieving a 16 bit resolution. Only you should be able to achieve that speed and good component matching. And importantly, the speed is a critereon. I am not sure whether Integrating ADCs achieve such high speeds.

But mostly people prefer sigma delta for these kind of resolutions and
 

thanks very much, but if you use dual slope, for the case of 9k samples/second, you must have a clock frequency of about 590 MHz (2^16*9000, because you must count down 2^16=65536 times to decide which level the sample is in), which is not quite feasible, is it ?
 

For SAR ADC, 16 bit is difficult. You need a 16 bit DAC first, which is already difficult without calibration or trimming.
 

It's impossible to get 16 bit SAR ADC without calibration.
And it's almost impossible to get even 12-bit SAR ADC w/o calibration.

You can check for ex. Analog Devices or MAXIM ADC spec:
AD7440 - 10 bit, AD7440A - 12 bit.
AD7621, MAX195 - 16 bit

Best regards
 

12 bit SAR is still feasible. Significantly more than that, you need to calibrate the internal DAC.
 

Before, I designed Sigma-Delta ADC. Sigma-Delta is a better choice to achieve 16-bit (SNR-->96dB) performance. And Sigma-Delta ADC is much easier than other types. Maybe Sigma-Delta ADC is a possibility for you.
 

although i don't think that sigma-delta ADC is easy, but it is a good choice to achieve 16-bit accuracy low speed ADC.
 

skjsun said:
is this actually doable in 0.35 um or 0.5 um CMOS nowadays without calibration or trimming ? i do not want to do a sigma-delta ADC for this "threshold" resolution (16 bits, cause it's high, but not too high to keep successive approximation out of choice), can anyone give me suggestions ?
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hi,sar adc is suitable for 10 bit, without trimming or calibration, it is hard to achieve 16bit. sdm adc is your choise.
 

I will rather say 16 bit SAR ADC is doable provided the MSPS is not very high !

Go for Time Interleaved SAR ADCs !! 2 SAR ADCs 8 bit each working in time-interleaved fashion will do ur job !!

Added after 1 minutes:

If its Audio, its very possible !!
 

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