Sumitomo Electric Industries, Limited

Semiconductor Technology Academic Research Center

Masato Kaneta

Haruo Kobayashi

Koichiro Mashiko

Tatsuji Matsuura

Akira Abe

Tatsuhiro Shimura

Hitoshi Hirata

Kazuya Shimizu

Katsuyoshi Yagi

Akihiro Kanbe

An envelope tracking power supply circuit is a power supply circuit for generating an output voltage according to the envelope of a high frequency signal and includes a voltage follower circuit for receiving an envelope signal and outputting a voltage according to the envelope signal; two parallel resistors connected in parallel between the output of the voltage follower circuit and an output terminal; hysteresis comparators for detecting respective voltage drops in the parallel resistors and generating voltages according to the voltage drops; and switching converters for performing switching according to the respective voltages outputted from the hysteresis comparators and outputting a voltage to the output terminal.

Envelope tracking power supply circuit and high-frequency amplifier including envelope tracking power supply circuit

A TDC circuit having a small scale circuit and high resolution is disclosed, which is a time-to-digital converter that detects a phase with respect to a reference clock of a signal to be measured, comprising a first delay line in which a plurality of first delay elements with a first delay amount is connected in series, a second delay line group that is connected to a plurality of connection nodes of the first delay line or an input node in the first stage and in which at least one or more second delay elements with a second delay amount different from the first delay amount are connected in series, a plurality of judgment circuits that judge whether the changing edge of the signal to be measured is advanced or delayed with respect to the changing edges of a delayed clock output from the first delay element and the second delay element, and an operation circuit that calculates a phase with respect to the reference clock of the changing edge of the signal to be measured from the judgment results, wherein a difference between the first delay amount and the second delay amount is smaller than the first delay amount and the second delay amount.

Time-to-digital converter

Growing community of inventors

Kiryu, Japan

Masato Kaneta