Voltage-signal generation

Patent metadata

Field	Value
Publication number	US-10784887-B2
Application number	US-201916719741-A
Country	US
Kind code	B2
Filing date	Dec 18, 2019
Priority date	Dec 19, 2018
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

Controllable voltage-signal generation circuitry, including: a plurality of segment nodes connected together in series, each adjacent pair of segment nodes connected together via a corresponding coupling capacitor, an end one of the segment nodes serving as an output node; for each of the segment nodes, at least one segment capacitor having a first terminal connected to that segment node and a second terminal connected to a corresponding switch; and switch control circuitry, wherein: each switch is operable to connect the second terminal to one reference voltage source and then instead to another reference voltage source, to apply a voltage change at the second terminal; the reference voltage sources and switches configured such that for each segment node the same voltage change in magnitude is applied by each switch, and such that the voltage change is different in magnitude from the voltage change applied by each switch of another segment node.

First claim

The invention claimed is:

1. Controllable voltage-signal generation circuitry, comprising:
a plurality of segment nodes connected together in series, each adjacent pair of segment nodes in the series connection being connected together via a corresponding coupling capacitor, an end one of the segment nodes in the series connection serving as an output node;
for each of the segment nodes, at least one segment capacitor having first and second terminals, the first terminal connected to that segment node and the second terminal connected to a corresponding switch; and
switch control circuitry,
wherein:
each switch is operable to connect the second terminal of its segment capacitor to one reference voltage source and then instead to another reference voltage source, those reference voltage sources having different voltage levels, to apply a voltage change at the second terminal of its segment capacitor;
the reference voltage sources and switches are configured such that for each segment node the same voltage change in magnitude is applied by each switch of that segment node, and such that the voltage change applied by each switch of one segment node is different in magnitude from the voltage change applied by each switch of another segment node; and
the switch control circuitry is configured to control the switches so as to control a voltage signal at said output node.

2. The controllable voltage-signal generation circuitry as claimed in claim 1 , wherein:
the plurality of segment nodes comprises at least three segment nodes; and/or
for each of the segment nodes, at least two or three said segment capacitors are connected at their first terminals to that segment node and at their second terminals to corresponding said switches, the capacitances of those segment capacitors optionally being binary-weighted relative to one another.

3. The controllable voltage-signal generation circuitry as claimed in claim 1 , wherein:
the plurality of segment nodes comprises at least three segment nodes; and
the reference voltage sources and switches are configured such that, for at least three said segment nodes, the voltage change applied by each switch of any one of those segment nodes is different in magnitude from the voltage change applied by each switch of the other segment nodes of those segment nodes.

4. The controllable voltage-signal generation circuitry as claimed in claim 1 , wherein:
at least one of said reference voltage sources is a variable reference voltage source configured to be adjusted to adjust the voltage change applied by each switch connected to that reference voltage source; and/or
at least one said reference voltage source connected to each switch is a variable reference voltage source configured to be adjusted to adjust the voltage change applied by each switch concerned.

5. The controllable voltage-signal generation circuitry as claimed in claim 1 , comprising:
calibration circuitry configured to adjust the voltage level of at least one of the reference voltage sources.

6. The controllable voltage-signal generation circuitry as claimed in claim 5 , wherein the calibration circuitry is configured to adjust the voltage level of at least one of the reference voltage sources connected to each switch for the segment node serving as the output node so as to adjust the voltage change applied by each switch of that segment node.

7. The controllable voltage-signal generation circuitry as claimed in claim 6 , wherein the calibration circuitry is configured to adjust the voltage change applied by each switch of the segment node serving as the output node to calibrate out a gain error of the controllable voltage-signal generation circuitry or to adjust the gain of the controllable voltage-signal generation circuitry.

8. The controllable voltage-signal generation circuitry as claimed in claim 5 , wherein the calibration circuitry is configured to adjust the voltage level of at least one of the reference voltage sources connected to each switch for at least one segment node other than the segment node serving as the output node so as to adjust the voltage change applied by each switch of that segment node.

9. The controllable voltage-signal generation circuitry as claimed in claim 8 , wherein the reference voltage sources are connected to the switches such that adjusting the voltage level of said at least one of the reference voltage sources connected to each switch for said at least one segment node other than the segment node serving as the output node adjusts the voltage change applied by each switch of that segment node:
independently of the voltage change applied by each switch of each other segment node; and/or
relative to the voltage change applied by each switch of the segment node serving as the output node.

10. The controllable voltage-signal generation circuitry as claimed in claim 8 , wherein the calibration circuitry is configured to adjust the voltage change applied by each switch of that segment node to calibrate out non-linearity errors caused by the controllable voltage-signal generation circuitry.

11. The controllable voltage-signal generation circuitry as claimed in claim 8 , wherein the calibration circuitry is configured to adjust the voltage change applied by each switch of that segment node to adjust a weighting of the effect of the voltage changes for that segment node relative to a weighting of the effect of the voltage changes for another said segment node.

12. Digital-to-analogue converter circuitry comprising the controllable voltage-signal generation circuitry as claimed in claim 1 , wherein the switch control circuitry is configured to control the switches in dependence upon a digital signal.

13. Integrated circuitry, such as an IC chip, comprising the digital-to-analogue converter circuitry as claimed in claim 12 .

14. Analogue-to-digital converter circuitry, comprising:
an analogue input terminal, operable to receive an analogue input voltage signal;
a comparator having first and second comparator-input terminals and operable to generate a comparison result based on a potential difference applied across those terminals; and
successive-approximation control circuitry configured to apply a potential difference across the first and second comparator-input terminals based upon the input voltage signal, and configured to control the potential difference for each of a series of successive approximation operations through charge redistribution, the control applied in each successive approximation operation being dependent on a comparison result generated by the comparator in the preceding approximation operation,
wherein:
the successive-approximation control circuitry comprises the controllable voltage-signal generation circuitry as claimed in claim 1 ; and
the switch control circuitry is configured to control the switches in each successive approximation operation in dependence upon the comparison result generated by the comparator in the preceding approximation operation.

15. The analogue-to-digital converter circuitry as claimed in claim 14 , wherein:
for each of at least two of the segment nodes, at least two or three said segment capacitors are connected at their first terminals to that segment node and at their second terminals to corresponding said switches, the capacitances of those segment capacitors being binary-weighted relative to one another; and
the reference voltage sources are configured so that a non-binary search is performed by the series of successive approximation operations, the search being non-binary in that across the series of successive approximatio

Assignees

• Socionext Inc

Inventors

• Rattan Suhas

Classifications

• H03M1/804

  with charge redistribution · CPC title

• H03M1/667 Primary

  Recirculation type · CPC title

• H03M1/001

  Analogue/digital/analogue conversion · CPC title

• H03M1/12

  Analogue/digital converters ({H03M1/001 – } H03M1/10 take precedence) · CPC title

• H03M1/38

  sequentially only, e.g. successive approximation type (converting more than one bit per step H03M1/14) · CPC title