Delta modulator with variable feedback gain, analog-to-digital converter including the delta modulator, and communication device including the delta modulator

Patent metadata

Field	Value
Publication number	US-10439636-B2
Application number	US-201816104414-A
Country	US
Kind code	B2
Filing date	Aug 17, 2018
Priority date	Jan 31, 2017
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A variable feedback gain delta modulator includes group of capacitors commonly connected to a first terminal and are respectively classified into a first capacitor group and a second capacitor group; a comparator for sequentially generating n-bit digital output signals based on a voltage of the first terminal; and a switch group including switches respectively connected to the capacitors, wherein the switches are respectively classified into a first switch group and a second switch group respectively connected to the first capacitor group and the second capacitor group, and the first switch group and the second switch group respectively operate according to a first control signal and a second control signal that are determined based on the n-bit digital output signals and the variable feedback gain.

First claim

What is claimed is:

1. A communication device comprising:
an analog-to-digital converter configured to convert an analog input signal into a digital output signal based on a reference voltage and comprising a delta modulator having a variable feedback gain; and
a reference voltage generator configured to generate and apply the reference voltage to the analog-to-digital converter,
wherein the reference voltage generator is further configured to determine a level of the reference voltage based on the variable feedback gain and maintain the level of the reference voltage in a sampling phase and a conversion phase,
wherein the level of the reference voltage is a first voltage level in response to the variable feedback gain being less than or equal to one, and
wherein the level of the reference voltage is a second voltage level corresponding to the first voltage level multiplied by the variable feedback gain in response to the variable feedback gain being greater than one.

2. The communication device of claim 1 , wherein the delta modulator comprises:
a capacitor group comprising a plurality of capacitors that are commonly connected to a first terminal, wherein the plurality of capacitors are respectively classified into a first capacitor group and a second capacitor group such that the delta modulator has the variable feedback gain;
a comparator configured to sequentially generate the digital output signal based on a voltage of the first terminal, the digital output signal having n-bits, wherein n is a positive integer; and
a switch group comprising a plurality of switches respectively connected to the plurality of capacitors, wherein the plurality of switches are respectively classified into a first switch group and a second switch group that are respectively connected to the first capacitor group and the second capacitor group, and the first switch group and the second switch group are configured to respectively operate according to a first control signal and a second control signal.

3. The communication device of claim 2 , wherein the delta modulator further comprises an input switch configured to receive the analog input signal and provide the analog input signal to the first terminal in the sampling phase.

4. The communication device of claim 2 , wherein the delta modulator further comprises a digital logic configured to:
sequentially receive the digital output signal from the comparator;
generate the first control signal and the second control signal; and
respectively provide the first control signal and the second control signal, as generated, to the first switch group and the second switch group.

5. The communication device of claim 2 , wherein the plurality of switches are configured to selectively connect a corresponding capacitor of the plurality of capacitors to a reference voltage terminal and a ground voltage terminal to which the reference voltage is applied, according to the first control signal and the second control signal.

6. The communication device of claim 2 , wherein the first control signal is determined based on the digital output signal and the second control signal is determined based on the digital output signal and the variable feedback gain,
wherein the first control signal corresponds to n-bit previous data in the sampling phase, and corresponds to n-bit current data that is sequentially output in the conversion phase, and
wherein the second control signal corresponds to the n-bit previous data in the sampling phase when the variable feedback gain is not less than one, and corresponds to the n-bit current data in the conversion phase when the variable feedback gain is not greater than one.

7. The communication device of claim 2 , wherein a ratio of a first capacitance of the first capacitor group to a second capacitance of the second capacitor group is x:(1−x), wherein x corresponds to the variable feedback gain.

8. The communication device of claim 7 , wherein the variable feedback gain multiplied by x corresponds to 1 in response to the variable feedback gain being greater than one, and
wherein x corresponds to the variable feedback gain in response to the variable feedback gain being less than one.

9. The communication device of claim 2 , wherein the first control signal and the second control signal are identical to each other as n-bit previous data in the sampling phase in response to the variable feedback gain being greater than one, and
wherein the first control signal is n-bit current data that is sequentially output and the second control signal is reset data that is not related to the n-bit current data in the conversion phase.

10. The communication device of claim 2 , wherein the first control signal is n-bit previous data and the second control signal is reset data that is not related to the n-bit previous data in the sampling phase in response to the variable feedback gain being less than one, and
wherein the first control signal and the second control signal are identical to each other as n-bit current data that is sequentially output in the conversion phase.

11. The communication device of claim 2 , wherein the first control signal is identical to the second control signal as n-bit previous data in the sampling phase in response to the variable feedback gain being equal to one, and
wherein the first control signal is identical to the second control signal as n-bit current data that is sequentially output in the conversion phase.

12. An analog-to-digital converter configured to convert an analog input signal into a digital output signal, the analog-to-digital converter comprising:
a delta modulator configured to receive the analog input signal in a sampling phase and output the digital output signal in a conversion phase, the delta modulator having a variable feedback gain,
wherein the delta modulator comprises:
a capacitor group comprising a plurality of capacitors that are commonly connected to a first terminal, wherein the plurality of capacitors are respectively classified into a first capacitor group and a second capacitor group such that the delta modulator has the variable feedback gain;
a comparator configured to sequentially generate the digital output signal based on a voltage of the first terminal, the digital output signal having n bits, wherein n is a positive integer; and
a switch group comprising a plurality of switches respectively connected to the plurality of capacitors, wherein the plurality of switches are respectively classified into a first switch group and a second switch group that are respectively connected to the first capacitor group and the second capacitor group, and the first switch group and the second switch group are configured to respectively operate according to a first control signal and a second control signal,

wherein a ratio of a first capacitance of the first capacitor group to a second capacitance of the second capacitor group is x:(1−x), x corresponding to the variable feedback gain,
wherein the variable feedback gain multiplied by x corresponds to one in response to the variable feedback gain being greater than one, and
wherein x corresponds to the variable feedback gain in response to the variable feedback gain being less than one.

13. The analog-to-digital converter of claim 12 , wherein the first control signal is determined based on the digital output signal and the second control signal is determined based on the digital output signal and the variable feedback gain,
wherein the first control signal corresponds to n-bit previous data in the sampling phase, and corresponds to n-bit current data that is sequentially output in the conversion pha

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Jae-Hoon
• Lee Jong-Woo
• Lo Chilun
• Oh Seung-Hyun
• Lee Jong-Mi

Classifications

• H03M3/434

  with multi-level feedback · CPC title

• H03M1/002

  Provisions or arrangements for saving power, e.g. by allowing a sleep mode, using lower supply voltage for downstream stages, using multiple clock domains or by selectively turning on stages when needed · CPC title

• H03M1/1245

  Details of sampling arrangements or methods · CPC title

• H03M3/436

  characterised by the order of the loop filter, e.g. error feedback type · CPC title

• H03M3/464 Primary

  Details of the digital/analogue conversion in the feedback path · CPC title