Kabushiki Kaisha Toshiba

Tomohiko Sugimoto

Hirotomo Ishii

Daisuke Kurose

Masanori Furuta

Kentaro Yoshioka

Takafumi Yamaji

Junya Matsuno

An amplifier circuit includes a sampling circuit and an amplifier connected to an output of the sampling circuit. A feedback capacitor is between an output terminal of the amplifier and an output terminal of the sampling circuit. A quantizer that includes a comparator is configured to quantize a voltage at the output terminal of the sampling circuit according to a comparison of a voltage at the output terminal of the sampling circuit to a voltage at the reference potential terminal of the comparator. The quantizer outputs a digital code according to the voltage comparison. A control circuit receives the digital code from the quantizer and stores the digital code in a register as a cancellation digital code. A digital-analog (D/A) converter outputs an analog signal in accordance with digital codes from the control circuit.

Amplifier circuit

A switched capacitor circuit includes a first sampling circuit having a first sampling capacitance element. The first sampling circuit receives an input voltage and outputs a sampled voltage according to a first sampling operation. A quantizer quantizes the sampled voltage output from the first sampling circuit and outputs a quantized value corresponding to the sampled voltage. A digital-to-analog converter outputs an analog signal in accordance with the quantized value from the quantizer. A first logic circuit outputs an instruction to start a sampling operation of a second sampling circuit, which is configured to sample the analog signal output from the digital-to-analog converter, when the quantizer completes quantization of the sampled voltage.

Switched capacitor circuit

According to one embodiment, an amplification circuit includes a differential amplifier and a feedback circuit. The differential amplifier includes a sampling circuit that samples a first voltage which is a difference between an adjustment voltage supplied to a first terminal and a first input voltage, and a second voltage which is a difference between the adjustment voltage and a second input voltage. The differential amplifier amplifies the first voltage to output a first voltage signal and amplifies the second voltage to output a second voltage signal. The feedback circuit detects a common mode voltage of the first voltage signal and the second voltage signal, and adjusts the adjustment voltage which is supplied to the first terminal in accordance with the common mode voltage.

Amplification circuit and analog/digital conversion circuit

According to one embodiment, a first AD converter converts a first voltage into a first digital signal. A voltage/time conversion circuit acquires a residual corresponding to a difference between the first voltage and a result of having converted the first digital signal into an analog signal and converts the residual into a time signal according to a voltage in a first capacitor. A time/voltage conversion circuit converts the time signal into a voltage signal according to a voltage in a second capacitor. A second AD converter converts the voltage signal into a second digital signal. A digital processing circuit outputs a third digital signal to adjust a current value of first or the second current sources based on the second digital signal.

Analog/digital conversion circuit

According to one embodiment, an amplifier circuit includes a first converter generating a time signal by voltage-time converting an input signal; a second converter generating an output signal by time-voltage converting the time signal; and a correction circuit outputting a control signal by comparing the time signal and a reference signal. The first converter generates the time signal, based on the control signal.

Amplifier circuit and pipeline type analog-digital converter

According to the present invention, a successive approximation type analog-digital converter includes: a comparator outputting a result of comparing an analog signal and a reference voltage; a register storing a digital value corresponding to the result of comparison and outputting a digital signal; a detection unit detecting whether the comparator is in a stable state or not for each bit; and a bit determination unit storing, if the comparator is not stable, as a bit value of a bit which is one bit lower-order than a corresponding detection bit, a value obtained by inverting a final determined bit value of the detection bit in the register instead of the comparison result of the comparator.

Analog-digital converter and analog-digital conversion method

According to an embodiment, there are provided a capacitor DAC for generating an output signal in accordance with a connection state of a capacitor element, a reference voltage generation circuit for supplying a reference voltage to the capacitor DAC, a comparator for outputting a comparison result in accordance with the output signal, a successive approximation register for outputting a digital signal in accordance with the comparison result, and a control circuit for controlling a connection state of the capacitor element in accordance with the comparison result and comparing an ideal code with a digital signal obtained by sampling a predetermined voltage, thereby correcting an error of the digital signal.

Analog-digital converter with calibration and receiver including the converter

A time error estimating device for estimating a sampling time error of each of a plurality of sampling circuits when the sampling circuits generates a plurality of sampling output signals by performing sampling at timings shifted from one another has correlators each configured to obtain a correlation value representing a similarity between the sampling output signals, and a weight adder configured to estimate the sampling time error of the sampling circuits, based on a result obtained by adjusting a weight on the correlation value.

Time error estimating device, error correction device and A/D converter

An A/D converter provides one or more operational amplifiers as components. The A/D converter includes a current controlling unit that is activated before an actual operation of the A/D converter to control a current of at least one of the operational amplifiers based on a settling characteristic of the operational amplifier.

Growing community of inventors

Kanagawa, Japan

Tomohiko Sugimoto