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US 2015/0091629 A1Published application
Bootstrap Circuit and Semiconductor Device Having Bootstrap Circuit
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsTakahiko ISHIZU, Kiyoshi KATO, Yutaka SHIONOIRI, Tatsuya ONUKI
Life of this patent
Estimating the term…
Abstract
A bootstrap circuit of which the capacitance of a bootstrap capacitor is small and which requires a shorter precharge period is provided. The bootstrap circuit includes transistors M41 and M42, capacitors BSC1 and BSC2, an inverter INV41, and keeper circuits 43 and 44. A signal OSG with a high voltage is generated from an input signal OSG_IN. As the signal OSG_IN is made a high level, a node SWG is made a high level by BSC1. After a signal BSE1 is made a high level and the node SWG is made a low level by the keeper circuit 44, a signal BSE2 is made a high level. By the capacitance coupling of BSC2, a voltage of an output terminal 22 increases.
Claims12
A bootstrap circuit comprising:
- a first input terminal and a second input terminal to which a first signal and a second signal are input, respectively;
- an output terminal;
- a first transistor;
- a first capacitor;
- and
- a first circuit,
- wherein one terminal of the first capacitor is connected to the second input terminal, and the other terminal of the first capacitor is connected to the output terminal,
- wherein the first transistor connects the first input terminal to the output terminal, and is diode-connected so as to allow a forward current to flow from the first input terminal to the output terminal, and
- wherein the first circuit has a function of maintaining a voltage of the output terminal at a low level when the first signal is input and the first signal is at a high level.
6 more elements
A bootstrap circuit comprising:
- a first input terminal and a second input terminal to which a first signal and a second signal are input, respectively;
- an output terminal;
- a first transistor and a second transistor;
- a first capacitor;
- and
- a first inverter,
- wherein one terminal of the first capacitor is connected to the second input terminal and the other terminal of the first capacitor is connected to the output terminal,
- wherein the first transistor connects the first input terminal to the output terminal, and is diode-connected so as to allow a forward current to flow from the first input terminal to the output terminal,
- wherein the second transistor connects the output terminal to a wiring to which a first voltage is input, and a gate of the second transistor is connected to an output node of the first inverter, and
- wherein an input node of the first inverter is connected to the first input terminal.
7 more elements
A bootstrap circuit comprising:
- a first input terminal, a second input terminal, and a third input terminal to which a first signal, a second signal, and a third signal are input, respectively;
- an output terminal;
- a first transistor and a second transistor;
- a first capacitor and a second capacitor;
- a first inverter;
- and
- a first circuit and a second circuit,
- wherein the third input terminal is connected to an input node of the first inverter,
- wherein the first transistor connects an output node of the first inverter to a gate of the second transistor, and is diode-connected so as to allow a forward current to flow from the output node of the first inverter to the gate of the second transistor,
- wherein the second transistor connects the first input terminal to the output terminal,
- wherein one terminal of the first capacitor is connected to the first input terminal and the other terminal of the first capacitor is connected to the gate of the second transistor,
- wherein one terminal of the second capacitor is connected to the second input terminal and the other terminal of the second capacitor is connected to the output terminal,
- wherein the first circuit has a function of maintaining a voltage of the output terminal at a low level when the first signal is input and the first signal is at a high level, and
- wherein the second circuit has a function of maintaining a gate voltage of the second transistor at a low level when a signal from the first inverter is input and the signal is at a high level.
11 more elements
A bootstrap circuit comprising:
- a first input terminal, a second input terminal, and a third input terminal to which a first signal, a second signal, and a third signal are input, respectively;
- an output terminal;
- a first transistor, a second transistor, a third transistor, and a fourth transistor;
- a first capacitor and a second capacitor;
- and
- a first inverter, a second inverter, and a third inverter,
- wherein the third input terminal is connected to an input node of the first inverter,
- wherein the first transistor connects an output node of the first inverter to a gate of the second transistor, and is diode-connected so as to allow a forward current to flow from the output node of the first inverter to the gate of the second transistor,
- wherein one terminal of the first capacitor is connected to the first input terminal and the other terminal of the first capacitor is connected to the gate of the second transistor,
- wherein one terminal of the second capacitor is connected to the second input terminal and the other terminal of the second capacitor is connected to the output terminal,
- wherein the second transistor connects the first input terminal to the output terminal, and is diode-connected so as to allow a forward current to flow from the first input terminal to the output terminal,
- wherein the third transistor connects the output terminal to a first wiring, and a gate of the third transistor is connected to an output node of the second inverter,
- wherein an input node of the second inverter is connected the first input terminal,
- wherein the fourth transistor connects the gate of the second transistor to a second wiring, and a gate of the fourth transistor is connected to an output node of the third inverter,
- wherein an input node of the third inverter is connected to the output node of the first inverter, and
- wherein a first voltage is input to the first wiring and the second wiring.
13 more elements
Dependencies are inferred from the claim text.