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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
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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 0.13µm 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 • 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 • A0 ~ gm/go • A0 > 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” • 0.18µm 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 • 0.18µm 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 0.13µm 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 0.13µm CMOS” • Double-sampled TI-architecture
S.Gupta et.al: “A 1GS/s 11b Time-Interleaved ADC in 0.13µm CMOS” • Timing scheme
S.Gupta et.al: “A 1GS/s 11b Time-Interleaved ADC in 0.13µm CMOS” • 11b 1GSps TI-converter • 0.13µm CMOS, 1.2V/2.5V supply • Peak SNR: 58.6dB, peak SNDR: 55dB • SNDR is 52dB with 400MHz input frequency • FOM < 0.5pJ