A/D conversion device

Patent metadata

Field	Value
Publication number	US-11070226-B2
Application number	US-202016937804-A
Country	US
Kind code	B2
Filing date	Jul 24, 2020
Priority date	Sep 9, 2019
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

An A/D conversion device, which operates in one mode including at least one of a ΔΣ mode, a cyclic mode, and a hybrid mode, includes: a first block that processes an analog input signal by a first amplifier; a second block including a second amplifier; a quantization unit that quantizes one of outputs of the first and second blocks; and a control circuit that switches the mode to perform a control corresponding to the mode.

First claim

What is claimed is:

1. An A/D conversion device that operates in at least two or more modes, which includes: a ΔΣ mode in which an analog input signal is processed by an A/D conversion process with a ΔΣ method; and a hybrid mode in which the analog input signal is processed by the A/D conversion process with the ΔΣ method and then a residual is processed by the A/D conversion process with a cyclic method, the A/D conversion device comprising:
a first block that receives the analog input signal and processes the analog input signal by a first amplifier;
a second block including a second amplifier that receives an output voltage of the first block;
a quantization unit that receives one of outputs of the first block and the second block and quantizes the one of the outputs; and
a control circuit that switches the at least two or more modes and controls a switching of a mode to perform a control corresponding to the mode, wherein:
in the ΔΣ mode, the control circuit uses the first amplifier of the first block and the second amplifier of the second block to quantize the output of the second block by the quantization unit and to process the output by the A/D conversion process with the ΔΣ method; and
in the hybrid mode, the control circuit uses the first amplifier of the first block without using the second amplifier of the second block to quantize the output of the first amplifier of the first block by the quantization unit with the ΔΣ method and to process the output by the A/D conversion process, and then the control circuit uses the first amplifier to process the residual by the A/D conversion process with the cyclic method.

2. The A/D conversion device according to claim 1 , wherein:
the first block includes a sampling capacitor for sampling the analog input signal; and
the sampling capacitor is configured so that an input sampling capacitance is switchable between the ΔΣ mode and a mode other than the ΔΣ mode.

3. The A/D conversion device according to claim 1 , wherein:
the first amplifier of the first block includes an operational amplifier that connects a feedback capacitor between an input node and an output node of the operational amplifier when the first block outputs an integrated voltage; and
the first amplifier of the first block shares another capacitor as the feedback capacitor when sampling the output of the first block with the cyclic method.

4. The A/D conversion device according to claim 1 , further comprising:
a sampling capacitor for sampling the analog input signal; and
a D/A converter that performs D/A conversion using a D/A converter capacitor in accordance with a digital output of the quantization unit when the A/D conversion process is performed with the ΔΣ method, wherein:
at least a part of the sampling capacitor and at least a part of the D/A converter capacitor are common.

5. The A/D conversion device according to claim 1 , wherein:
the quantization unit includes:
a first quantizer that quantizes the output of the second amplifier of the second block in the ΔΣ mode; and
a second quantizer that quantizes the output of the first amplifier of the first block in the mode other than the ΔΣ mode.

6. The A/D conversion device according to claim 1 , further comprising:
a current cut unit that cuts a current of the second amplifier of the second block in the mode other than the ΔΣ mode.

7. The A/D conversion device according to claim 6 wherein:
in the mode other than ΔΣ mode, a common mode feedback circuit of the second amplifier of the second block is operated, and another circuit is not operated.

8. An A/D conversion device that operates in at least two or more modes, which includes: a ΔΣ mode in which an analog input signal is processed by an A/D conversion process with a ΔΣ method; and a cyclic mode in which the analog input signal is processed by the A/D conversion process with a cyclic method, the A/D conversion device comprising:
a first block that receives the analog input signal and processes the analog input signal by a first amplifier;
a second block including a second amplifier that receives an output voltage of the first block;
a quantization unit that receives one of outputs of the first block and the second block and quantizes the one of the outputs; and
a control circuit that switches the at least two or more modes and controls a switching of a mode to perform a control corresponding to the mode, wherein:
in the ΔΣ mode, the control circuit uses the first amplifier of the first block and the second amplifier of the second block to quantize the output of the second block by the quantization unit and to process the output by the A/D conversion process with the ΔΣ method; and
in the cyclic mode, the control circuit uses the first amplifier of the first block without using the second amplifier of the second block to quantize the output of the first amplifier of the first block by the quantization unit and to process the output by the A/D conversion process with the cyclic method.

9. The A/D conversion device according to claim 8 , wherein:
the first block includes a sampling capacitor for sampling the analog input signal; and
the sampling capacitor is configured so that an input sampling capacitance is switchable between the ΔΣ mode and a mode other than the ΔΣ mode.

10. The A/D conversion device according to claim 8 , wherein:
the first amplifier of the first block includes an operational amplifier that connects a feedback capacitor between an input node and an output node of the operational amplifier when the first block outputs an integrated voltage; and
the first amplifier of the first block shares another capacitor as the feedback capacitor when sampling the output of the first block with the cyclic method.

11. The A/D conversion device according to claim 8 , further comprising:
a sampling capacitor for sampling the analog input signal; and
a D/A converter that performs D/A conversion using a D/A converter capacitor in accordance with a digital output of the quantization unit when the A/D conversion process is performed with the ΔΣ method, wherein:
at least a part of the sampling capacitor and at least a part of the D/A converter capacitor are common.

12. The A/D conversion device according to claim 8 , wherein:
the quantization unit includes:
a first quantizer that quantizes the output of the second amplifier of the second block in the ΔΣ mode; and
a second quantizer that quantizes the output of the first amplifier of the first block in the mode other than the ΔΣ mode.

13. The A/D conversion device according to claim 8 , further comprising:
a current cut unit that cuts a current of the second amplifier of the second block in the mode other than the ΔΣ mode.

14. The A/D conversion device according to claim 13 wherein:
in the mode other than ΔΣ mode, a common mode feedback circuit of the second amplifier of the second block is operated, and another circuit is not operated.

15. An A/D conversion device that operates in at least three or more modes, which includes: a ΔΣ mode in which an analog input signal is processed by an A/D conversion process with a ΔΣ method; a cyclic mode in which the analog input signal is processed by the A/D conversion process with a cyclic method; and a hybrid mode in which the analog input signal is processed by the A/D conversion process with the ΔΣ method and then a residual is processed by the A/D conversion process with a cyclic method, the A/D conversion device comprising:
a first block that receives the analog input signal and processes the analog input signal by a first amplifier;
a second blo

Assignees

• Denso Corp

Inventors

• Nakamura Kunihiko
• Nezuka Tomohiro
• Honda Kazutaka

Classifications

• H03M3/496

  Details of sampling arrangements or methods · CPC title

• H03M1/144

  the steps being performed sequentially in a single stage, i.e. recirculation type (H03M1/141, H03M1/143, H03M1/16 take precedence) · CPC title

• H03M3/392 Primary

  Arrangements for selecting among plural operation modes, e.g. for multi-standard operation · CPC title

• H03M1/804

  with charge redistribution · CPC title

• H03M1/06 Primary

  Continuously compensating for, or preventing, undesired influence of physical parameters (periodically, {e.g. by using stored correction values,} H03M1/10) · CPC title