PowerPoint Template

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Nyquist Rate ADCs
Dr. Hossein Shamsi ECE Dept, K.N. Toosi
University of Technology
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Sample and Hold Circuits
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Ideal Track-and-Hold Circuit
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Nonidealities
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Non-zero Acquisition Time
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Non-zero Acquisition Time
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Thermal Noise
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Contd
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Voltage Dependence of Switch (Switch
non-linearity)
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Signal Dependent Sampling Instant
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Hold Mode Leakage
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Charge Injection and Clock Feedthrough
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First Order Improvements
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Charge Cancellation
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Differential Sampling
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CMOS Switch
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On Resistance of CMOS Switch
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Analysis
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Outline

• Elementary track-and-hold circuit and its
  nonidealities
• First order improvements to elementary
  track-and-hold

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Clock Bootstrapping
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Waveforms
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Circuit Implementation
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Bottom Plate Sampling Analysis (1)
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Bottom Plate Sampling Analysis (2)
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Fully Differential SHA Circuit
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Fully Differential SHA Circuit (contd)
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Fully Differential T/H Circuit (contd)
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Flip-Around T/H
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Capacitors and Plate Parasitics
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Proper Connection of Capacitors