# US 2010/0164767 A1 · Digital calibration type analog-to-digital converter and wireless receiver circuit and wireless transceiver circuit using the same

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- Number: US 2010/0164767 A1
- Document ID: US20100164767A1
- Status: Published application
- Kind: A1
- Application number: 12/720,669
- Filed: 2010-03-10
- Published: 2010-07-01
- Earliest claimed: 2007-10-03
- Assignees: Hitachi, Ltd.
- Inventors: TAKASHI OSHIMA; Taizo Yamawaki
- Web page: https://patentgrep.com/patent/US20100164767A1

## CPC

- H03M 1/1004: {without interrupting normal operation, e.g. by providing an additional component for temporarily replacing components to be tested or calibrated (H03M1/1009, H03M1/1071 take precedence)}
- H03M 1/1009: {Calibration}
- H03M 1/002: {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}
- H03M 1/005: {among different converters types}
- H03M 1/126: {Multi-rate systems, i.e. adaptive to different fixed sampling rates}
- H03M 1/44: Sequential comparisons in series-connected stages with change in value of analogue signal
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

In a wireless chip receiving the multi-rate data according to the related art, power consumption and a circuit area of an analog-to-digital converter become large. In a digital calibration type analog-to-digital converter including both a reference analog-to-digital conversion unit and a main analog-to-digital conversion unit, when processing the high-sample rate wireless receive signal, both the reference analog-to-digital conversion unit and the main analog-to-digital conversion unit are operated to configure a general digital calibration type analog-to-digital converter, and when processing a low-sample rate wireless receive signal, analog-to-digital conversion is performed by using the reference analog-to-digital conversion unit and operations of the main analog-to-digital conversion unit or the like are stopped to remarkably reduce power consumption.

## Claims

### Claim at position 1

1-20. (canceled)

### Claim 21

An A/D converter comprising;
a first A/D conversion unit;
a second A/D conversion unit;
a digital calibration section which calibrates an output of the first A/D conversion unit; and
a controller which operates based on an information of input-signal identification,
wherein the second A/D conversion unit performs A/D conversion with higher accuracy at slower sampling rate than the first A/D conversion unit,
wherein when the information of input-signal identification indicates that an input signal to the A/D converter is a first signal, the controller controls in such a way that A/D conversion is performed by the first A/D conversion unit, the second A/D conversion unit and the digital calibration section, and A/D conversion result of the first signal is obtained from an output of the digital calibration section, and
when the information of input-signal identification indicates that the input signal to the A/D converter is a second signal which has narrower bandwidth than the first signal, the controller controls in such a way that A/D conversion is performed by the second A/D conversion unit, and A/D conversion result of the second signal is obtained from an output of the second A/D conversion unit.

### Claim 22 (depends on 21)

The A/D converter according to claim 21,
wherein the first A/D conversion unit is a pipelined A/D converter.

### Claim 23 (depends on 21)

The A/D converter according to claim 21,
wherein the first A/D conversion unit is a successive approximation register A/D converter.

### Claim 24

A wireless transceiver comprising:
a wireless transceiver circuit; and
an A/D converter,
wherein the A/D converter comprises a first A/D conversion unit, a second A/D conversion unit, a digital calibration section which calibrates an output of the first A/D conversion unit, and a controller which operates based on an information of input-signal identification,
wherein the second A/D conversion unit performs A/D conversion with higher accuracy at slower sampling rate than the first A/D conversion unit,
wherein when the information of input-signal identification indicates that an input signal to the A/D converter is a first signal, the controller controls in such a way that A/D conversion is performed by the first A/D conversion unit, the second A/D conversion unit and the digital calibration section, and A/D conversion result of the first signal is obtained from an output of the digital calibration section, and
wherein when the information of input-signal identification indicates that the input signal to the A/D converter is a second signal which corresponds to slower data rate than the first signal, the controller controls in such a way that A/D conversion is performed by the second A/D conversion unit, and A/D conversion result of the second signal is obtained from an output of the second A/D conversion unit.

### Claim 25

A medical apparatus comprising:
a sensor section;
an analog front-end circuit; and
an A/D converter,
wherein the A/D converter comprises a first A/D conversion unit, a second A/D conversion unit, a digital calibration section which calibrates an output of the first A/D conversion unit, and a controller which operates based on an information of input-signal identification,
wherein the second A/D conversion unit performs A/D conversion with higher accuracy at slower sampling rate than the first A/D conversion unit,
wherein when the information of input-signal identification indicates that the input signal to the A/D converter is a first signal, the controller controls in such a way that A/D conversion is performed by the first A/D conversion unit, the second A/D conversion unit and the digital calibration section, and A/D conversion result of the first signal is obtained from an output of the digital calibration section, and
wherein when the information of input-signal identification indicates that the input signal to the A/D converter is a second signal which has narrower bandwidth than the first signal, the controller controls in such a way that A/D conversion is performed by the second A/D conversion unit, and A/D conversion result of the second signal is obtained from an output of the second A/D conversion unit.