US 10,651,790 B2Granted

Semiconductor device and electronic device

AssigneeSemiconductor Energy Laboratory Co., Ltd.

InventorsYuki Okamoto, Yoshiyuki Kurokawa

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Abstract

An oscillator capable of quick startup is provided. A transistor is provided between an output terminal of a certain stage inverter and an input terminal of the following stage inverter included in the voltage controlled oscillator. With the use of the on resistance of the transistor, the oscillation frequency of the clock signal is controlled. While supply of the power supply voltage is stopped, a signal that is input to the input terminal of the inverter just before supply of the power supply voltage is stopped is stored by turning off the transistor. This operation makes it possible to immediately output a clock signal that has the same frequency as that before supply of the power supply voltage is stopped at the time when the power supply voltage is supplied again.

Claims28

Dependent claims

A semiconductor device comprising a circuit, the circuit comprising:

a first transistor;
a second transistor;
a third transistor;
a fourth transistor;
a fifth transistor;
and
a capacitor,
wherein the first transistor has a polarity different from a polarity of the second transistor,
wherein the fifth transistor has the same polarity as the second transistor,
wherein a gate of the first transistor is electrically connected to a gate of the second transistor,
wherein one of a source and a drain of the first transistor is electrically connected to one of a source and a drain of the second transistor and one of a source and a drain of the fifth transistor,
wherein a gate of the fifth transistor is directly connected to the other of the source and the drain of the first transistor,
wherein the other of the source and the drain of the fifth transistor is electrically connected to one of a source and a drain of the third transistor,
wherein a gate of the third transistor is electrically connected to one of a source and a drain of the fourth transistor and a first electrode of the capacitor, and
wherein a second electrode of the capacitor is electrically connected to the other of the source and the drain of the second transistor.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/046,277Filed 26 Jul 2018 · division
Priority: JP 2015-21370830 Oct 2015
Published: US 2018/0358925 A113 Dec 2018
Granted: 12 May 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H03B 5/06
Details: modifications of generator to ensure starting of oscillations
H03K 3/014
Details: modifications of generator to ensure starting of oscillations
H03K 3/0315
Astable circuits: ring oscillators
H10D 30/6755
Characterised by the active materials: oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate

Family

Application15/298,305Parent of this division · filed 20 Oct 2016
US 2018/0358925 A1Pre-grant publication · published 13 Dec 2018
US 10,038,402 B2Parent of this division
US 2017/0126176 A1Published application
US 10,651,790 B2This patent

From the US filing history. Foreign family members aren’t listed.