Differential sampler structures with reduced distortion and current demand
AssigneeAnalog Devices, Inc.
InventorChristopher Daniel Dillon
Life of this patent
Estimating the term…
Abstract
Differential sampler structures are provided that reduce signal distortion and current demand. The structures include first and second buffers that drive first and second capacitors and first and second switches. First and second current pumps are capacitively coupled and also cross coupled to the first and second capacitors relative to the coupling of the first and second buffers to these capacitors. As a result, signal distortion and current demand are both reduced.
Claims23
A differential driver that drives first and second output sides of a differential output port in response to first and second input portions of a differential input signal, comprising:
- first and second buffers that respectively drive said first and second output sides in respective response to said first and second input portions;
- and
- first and second capacitively-coupled current pumps that respectively provide currents to said second and first output sides in respective response to said first and second input portions.
A sampler that provides samples of a differential input signal in response to a command signal, comprising:
- first and second sample capacitors;
- first and second buffers that respectively drive said first and second sample capacitors in response to said differential input signal;
- first and second switches that respond to said command signal and are respectively serially-coupled with said first and second sample capacitors;
- and
- first and second current pumps that are capacitively coupled to respectively respond with said first and second buffers to said differential input signal and, in response, provide currents respectively to said second and first buffers.
A pipelined analog-to-digital converter that processes a differential input signal to a corresponding digital signal, comprising:
- an initial converter stage that processes samples of said differential input signal to provide a residue signal and respective bits of said digital signal;
- at least one successive converter stage that processes a preceding residue signal to provide a successive residue signal and respective bits of said digital signal wherein a final converter stage only provides said respective bits;
- and
- at least one sampler that is positioned in said initial converter stage and includes:
- a) first and second sample capacitors;
- b) first and second buffers that respectively drive said first and second sample capacitors in response to said differential input signal;
- c) first and second switches that respond to said command signal and are respectively serially-coupled with said first and second sample capacitors;
- d) first and second mimic buffers that are coupled to respectively respond with said first and second buffers to said differential input signal;
- e) first and second current mirrors coupled to mirror current respectively to said second and first buffers;
- and
- f) first and second mimic capacitors that respectively couple said first mimic buffer to drive said first current mirror and couple said second mimic buffer to drive said second current mirror.
Dependencies are inferred from the claim text.