Patents by Inventor Ayuko Watabe
Ayuko Watabe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7113041Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.Type: GrantFiled: April 19, 2005Date of Patent: September 26, 2006Assignee: Fujitsu LimitedInventors: Katsuyuki Yasukouchi, Ayuko Watabe
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Publication number: 20050179496Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.Type: ApplicationFiled: April 19, 2005Publication date: August 18, 2005Inventors: Katsuyuki Yasukouchi, Ayuko Watabe
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Patent number: 6903609Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.Type: GrantFiled: March 29, 2002Date of Patent: June 7, 2005Assignee: Fujitsu LimitedInventors: Katsuyuki Yasukouchi, Ayuko Watabe
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Patent number: 6806770Abstract: An operational amplifier for increasing the response speed of its output voltage relative to an input signal while increasing the tolerable amplitude of the output voltage. The operational amplifier includes a PNP output transistor connected to a high potential power supply, an NPN output transistor connected between the PNP output transistor and a low potential power supply, and a drive unit, which drives each output transistor in accordance with an input current. The drive unit includes a current source, a first current mirror circuit, and a second mirror circuit. The input current is supplied to a node between the first and second current mirror circuits. The base of the NPN output transistor is connected to the node, and the base of the PNP output transistor is connected to a further node between the current source and the first current mirror circuit.Type: GrantFiled: April 21, 2003Date of Patent: October 19, 2004Assignee: Fujitsu LimitedInventors: Katsuyuki Yasukouchi, Ayuko Watabe
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Patent number: 6741105Abstract: A peak hold circuit which improves the precision of a hold voltage. The peak hold circuit includes a first input transistor which receives an input voltage and a second input transistor which receives the hold voltage. The peak hold circuit further includes a hold capacitor, a hold-voltage setting transistor and a bypass circuit. The hold capacitor supplies the hold voltage to the second input transistor. The hold-voltage setting transistor receives base current from the collector of the first input transistor and makes the hold voltage coincide with the input voltage in accordance with the base current. The bypass circuit bypasses bias current to be supplied to the second input transistor when the hold-voltage setting transistor is turned off.Type: GrantFiled: April 18, 2003Date of Patent: May 25, 2004Assignee: Fujitsu LimitedInventors: Katsuyuki Yasukouchi, Ayuko Watabe, Katsuya Shimizu
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Publication number: 20030201828Abstract: An operational amplifier for increasing the response speed of its output voltage relative to an input signal while increasing the tolerable amplitude of the output voltage. The operational amplifier includes a PNP output transistor connected to a high potential power supply, an NPN output transistor connected between the PNP output transistor and a low potential power supply, and a drive unit, which drives each output transistor in accordance with an input current. The drive unit includes a current source, a first current mirror circuit, and a second mirror circuit. The input current is supplied to a node between the first and second current mirror circuits. The base of the NPN output transistor is connected to the node, and the base of the PNP output transistor is connected to a further node between the current source and the first current mirror circuit.Type: ApplicationFiled: April 21, 2003Publication date: October 30, 2003Applicant: FUJITSU LIMITEDInventors: Katsuyuki Yasukouchi, Ayuko Watabe
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Publication number: 20030201801Abstract: A peak hold circuit which improves the precision of a hold voltage. The peak hold circuit includes a first input transistor which receives an input voltage and a second input transistor which receives the hold voltage. The peak hold circuit further includes a hold capacitor, a hold-voltage setting transistor and a bypass circuit. The hold capacitor supplies the hold voltage to the second input transistor. The hold-voltage setting transistor receives base current from the collector of the first input transistor and makes the hold voltage coincide with the input voltage in accordance with the base current. The bypass circuit bypasses bias current to be supplied to the second input transistor when the hold-voltage setting transistor is turned off.Type: ApplicationFiled: April 18, 2003Publication date: October 30, 2003Applicant: FUJITSU LIMITEDInventors: Katsuyuki Yasukouchi, Ayuko Watabe, Katsuya Shimizu
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Publication number: 20030042982Abstract: An operational amplifier that decreases idling current, widens a voltage output range, and increases load driving capacity. The operational amplifier includes a first output transistor connected to a high potential power supply. A second output transistor is connected between the first output transistor and a low potential power supply. The first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor. An idling current control circuit controls the collector current of the first output transistor in accordance with the base voltage of the second output transistor to control the idling current of the first and second output transistors.Type: ApplicationFiled: March 29, 2002Publication date: March 6, 2003Applicant: Fujitsu LimitedInventors: Katsuyuki Yasukouchi, Ayuko Watabe