Sony Corporation

Kouhei Kudou

Yasuhide Shimizu

Yukitoshi Yamashita

Shinichirou Etou

Shigemitsu Murayama

Norifumi Kanagawa

Disclosed herein is a differential amplifier including: an input terminal configured to receive an input signal; an output terminal configured to output an output signal obtained as a result of amplifying the input signal; an amplification part configured to amplify the input signal to generate the output signal; a load circuit which is connected between the amplification part and a power-supply terminal, and is provided with a first-conduction transistor, and a changeover switch configured to switch a connection between a gate electrode of the first-conduction transistor and a drain electrode of the first-conduction transistor to a connection between the gate electrode and the output terminal or vice versa; and a leak cancel switch configured to generate a leak cancel current for reducing an off leak current flowing through the changeover switch.

Differential amplifier and analog/digital converter

An AD converter includes: AD conversion stages configured to generate digital data having a value corresponding to a relationship between two analog signals being input and amplifying two analog residual signals with a first amplifier and a second amplifier with gain to be controlled to output the signals; and a gain control part configured to control gain of the first amplifier and the second amplifier on the basis of a monitoring result of the output signals of the first amplifier and the second amplifier. The first amplifier and the second amplifier are formed of open-loop amplifiers, and the gain control part takes out amplitude information of the output signals of the first amplifier and the second amplifier in at least one of the AD conversion stages and performs gain control so that amplitude of the analog signals being output from the stage converges on setting amplitude being set.

Analog-digital converter and signal processing system

An analog-to-digital (A/D) converter includes: a coarse A/D converter configured to convert, when converting an analog input signal into an N-bit digital signal, the analog input signal into a high-order m-bit digital signal; a fine A/D converter configured to convert the analog input signal into a low-order n-bit (where n=N&#x2212;m) digital signal based on a conversion result of the coarse A/D converter; and a track-and-hold (TH) circuit configured to sample the analog input signal, to supply a comparison voltage compared with a coarse reference voltage to the coarse A/D converter, and to supply a comparison voltage compared with a fine reference voltage based on a conversion result of the fine A/D converter to the fine A/D converter. The TH circuit is configured to share a sampling capacitor in a selective input path for the analog input signal, the coarse reference voltage, and the fine reference voltage.

Growing community of inventors

Nagasaki, Japan

Kouhei Kudou