Transcript Gain calibration of pipelined ADCs
FE8113 ”High Speed Data Converters”
Part 3: High-Speed ADCs
Papers 10, 11, 12 and 13
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” , IEEE ISSCC2006 S T.Ryu et.al: “
A 10b 50MS/s Pipelined ADC With Opamp Current Reuse
” , IEEE ISSCC2006 T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS TEchnologies
” , IEEE ISSCC2006 S.Gupta et.al: “
A 1GS/s 11b Time-Interleaved ADC in 0.13
µm CMOS
” , IEEE ISSCC2006
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” 10b Pipelined ADC
FOM
Power
/(2
ENOB
f
) This converter: 0.5pJ
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” Sampling to ground Sampling to virtual ground minimizes 1/f-noise and opamp offset effects. However, high-frequency opamp noise is added during sampling Large input transistor to minimze 1/f-noise
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” Two-stage Miller opamp Folded cascode first stage A 0 A 0 ~ g m /g o > 65dB over a large bias range
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” Measured dynamic performance
G.Geelen et.al: “
A 90nm CMOS 1.2V 10b Power and Speed Programmable Pipelined ADC With 0.5pJ/Conversion-Step
” Performance summary
S T.Ryu et.al: “
A 10b 50MS/s Pipelined ADC With Opamp Current Reuse
” Pipelined ADC Two first stages: N-Input MDAC Two last stages: P-Input MDAC P- and N-input MDACs share bias current
S T.Ryu et.al: “
A 10b 50MS/s Pipelined ADC With Opamp Current Reuse
” MDAC operation with simplified opamp schematic
S T.Ryu et.al: “
A 10b 50MS/s Pipelined ADC With Opamp Current Reuse
” Opampwith both P and N inputs Gain-boosted opamp with capacitive CMFB NMOS boost amplifiers. Capacitive level shifting allows NMOS boost amplifiers for both P and N cascodes
S T.Ryu et.al: “
A 10b 50MS/s Pipelined ADC With Opamp Current Reuse
” 0.18
µm CMOS, 1.8V supply Power consumption: 18mW @ 50MS/s DNL: +/- 0.2 LSB, INL: +/- 0.4LSB
ENOB: 9.2b/8.8b for 1MHz/20MHz inputs SFDR ~ 70dB
T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS TEchnologies
” High-gain opamps without reduced signal swing is difficult to design in modern technologies Open-loop amplification avoids this, but requires calibration New appraoch: Use a comparator to detect virtual ground It is easier to detect the virtual ground than forcing it Will work for all sampled-data, switch-cap systems (filters, pipeline stages ++)
T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS Technologies
” Comparator/loop delay results in overshoot Use a coarse and a fine current source With constant delay and current, this leads to a constant offset at the output
T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS Technologies
” 10b pipeline prototype design 1.5b stages, cascaded with no scaling Proof-of-concept design
T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS Technologies
” Continuous-time comparator
T.Sepke et.al: “
Comparator-Based Switched Capacitor Circuits For Scaled CMOS Technologies
” 10b 8MHz pipeline 0.18
µm CMOS, 1.8V supply Power consumption: 2.5mW @ 8MS/s DNL: 0.33/-0.28 LSB, INL: 1.59/-1.13 LSB Input-refferd rms noise: 0.65 LSB FOM: 0.3pJ/b
S.Gupta et.al: “
A 1GS/s 11b Time-Interleaved ADC in 0.13
µm CMOS
” 11b 1GS/s TI-converter Input S/H switch to eliminate timing errors Double sampling in sub-ADCs to reduce the number of sub-converters
S.Gupta et.al: “
A 1GS/s 11b Time-Interleaved ADC in 0.13
µm CMOS
” Double-sampled TI-architecture
S.Gupta et.al: “
A 1GS/s 11b Time-Interleaved ADC in 0.13
µm CMOS
” Timing scheme
S.Gupta et.al: “
A 1GS/s 11b Time-Interleaved ADC in 0.13
µm CMOS
” 11b 1GSps TI-converter 0.13
µm CMOS, 1.2V/2.5V supply Peak SNR: 58.6dB, peak SNDR: 55dB SNDR is 52dB with 400MHz input frequency FOM < 0.5pJ