Thanks for gevy ^^
But how to completely?
1.5 bit sub-adc need Vref between +1/4Vref and -1/4Vref
2 bit sub-adc need Vref between +1/2Vref, 0 and -1/2Vref
I'm read IEEE paper, A 10b 20Msamples/s analog to digital converver, P354
"each core stage contained an ADSC and DAC that shared a common resistor string, the resistor determine the ADSC decision"
I don't know how to completely 1.5bit and 2bit circuit
How many resistor i need in 1.5bit and 2bit sub-adc?
Please help me,friends