HIDETO TAKAGISHI
Pilots at Arbor Park Ct, San Jose, CA
License number
California A3840038
Issued Date
May 2015
Expiration Date
May 2017
Category
Airmen
Type
Authorized Aircraft Instructor
Address
Address
1347 Arbor Park Ct, San Jose, CA 95126
Professional information
Class D Audio Amplifier
US Patent:
6476673, Nov 5, 2002
Filed:
Jun 19, 2001
Appl. No.:
09/885155
Inventors:
Hideto Takagishi - San Jose CA
Assignee:
Monolithic Power Systems, Inc. - Santa Clara CA
International Classification:
H03F 338
US Classification:
330 10, 330207 A
Abstract:
A Class D amplifier circuit performs audio signal processing and other signal processing by using a bang-bang controller and a noise-shaping feedback network. The bang-bang controller triggers generation of a rectangular waveform that corresponds to changes in a control signal derived from an input analog signal, with the generation of the rectangular waveform being based on a comparison of the control signal with another signal derived from hysteresis associated with an output of a comparator. A filter filters the rectangular waveform to obtain an amplified output analog signal substantially representative of the input analog signal. The feedback network noise shapes the output analog signal, and feeds back the noise-shaped output analog signal and substracts it from the input analog signal.
Class D Audio Amplifier
US Patent:
6420930, Jul 16, 2002
Filed:
Jul 12, 2000
Appl. No.:
09/614410
Inventors:
Hideto Takagishi - San Jose CA
Assignee:
Monolithic Power Systems, Inc. - Santa Clara CA
International Classification:
H03F 3217
US Classification:
330251, 330207 A
Abstract:
A Class D amplifier circuit performs audio signal processing and other signal processing by using a bang-bang controller and a noise-shaping feedback network. The bang-bang controller triggers generation of a rectangular waveform that corresponds to changes in a control signal derived from an input analog signal, with the generation of the rectangular waveform being based on a comparison of the control signal with another signal derived from hysteresis associated with an output of a comparator. A filter filters the rectangular waveform to obtain an amplified output analog signal substantially representative of the input analog signal. The feedback network noise shapes the output analog signal, and feeds back the noise-shaped output analog signal and substracts it from the input analog signal.
Battery Charger
US Patent:
6437549, Aug 20, 2002
Filed:
Aug 31, 2000
Appl. No.:
09/653114
Inventors:
Hideto Takagishi - San Jose CA
Assignee:
Monolithic Power Systems, Inc. - Santa Clara CA
International Classification:
G05F 140
US Classification:
323282, 323284
Abstract:
A battery charger is provided that does not sink current from the battery during a reverse mode of operation. The battery charger includes upper and lower switching circuits, which alternately activate and deactivate to provide outgoing current flow. A comparator is coupled to the lower switching circuit to detect current flow into the upper and lower switching circuits. If this current flow is detected, a control circuit is provided that will deactivate the lower switching circuit to prevent subsequent incoming current flow. Further, a transistor is coupled to the lower switching circuit to detect the incoming current flow.
Class D Amplifier No Low Pass Filter Feedback With Zero Phase Delay
US Patent:
5949282, Sep 7, 1999
Filed:
Feb 25, 1998
Appl. No.:
9/030746
Inventors:
Huey Nguyen - San Jose CA
Hideto Takagishi - San Jose CA
Hideto Takagishi - San Jose CA
Assignee:
National Semiconductor Corporation - Santa Clara CA
International Classification:
H03F 338
US Classification:
330 10
Abstract:
A circuit for generating an accurate reproduction of the output of a Class D amplifier for error-correction purposes includes a reference signal amplifier circuit. The reference signal amplifier circuit includes an op-amp configured as a differential amplifier that combines the digital outputs of the internal output stage of the amplifier into a single reference signal. By reducing the bandwidth of the op-amp, switching noise is removed from the digital signals, without adding any phase shift to the generated reference signal. In addition, by using the digital signals directly from the output stage rather than the filtered analog outputs of the amplifier, distortion due to external speaker-induced back-EMF is prevented. The reference signal can then be compared to the original signal input to the amplifier for error-correcting purposes.
Method And Apparatus For Self-Oscillating Differential Feedback Class-D Amplifier
US Patent:
7046727, May 16, 2006
Filed:
May 5, 2004
Appl. No.:
10/839755
Inventors:
Hideto Takagishi - San Jose CA, US
Assignee:
Monolithic Power Systems, Inc. - Los Gatos CA
International Classification:
H03K 7/08
US Classification:
375238, 330 10
Abstract:
The present disclosure introduces a simple method and apparatus for a Class-D amplification and Pulse Width Modulation (PWM) of an input signal, such as a voice signal. The proposed circuits do not require reference input signals such as triangular signals; rather, the combination of the circuits' self-oscillating device arrangements and the delay elements performs pulse width modulation at higher frequencies while producing less noise. Among other advantages, these circuits offer shorter response time, less distortion, better power supply ripple rejection, larger negative feedback, and simpler construction. The recommended Class-D amplifiers can be used with speakers and can have single-ended or differential input.
Switching Amplifier Circuits And Methods
US Patent:
2008010, May 1, 2008
Filed:
Oct 27, 2006
Appl. No.:
11/588799
Inventors:
Hideto Takagishi - San Jose CA, US
Assignee:
PacificTech Microelectronics, Inc. - Grand Cayman
International Classification:
H03F 21/00, H02B 1/00, H03F 3/38
US Classification:
381120, 330 10, 330251, 381123
Abstract:
Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes an audio amplification method comprising modulating an audio input signal to produce a first modulated signal and a second modulated signal, amplifying the first modulated signal to generate an amplified first modulated signal at a first output terminal of an amplifier, and amplifying the second modulated signal to generate an amplified second modulated signal at a second output terminal of the amplifier, wherein the first output terminal of the amplifier is constant when the second output terminal of the amplifier is switching, and wherein the second output terminal of the amplifier is constant when the first output terminal of the amplifier is switching.
Low Distortion Switching Amplifier Circuits And Methods
US Patent:
8111846, Feb 7, 2012
Filed:
Aug 7, 2007
Appl. No.:
11/890813
Inventors:
Hideto Takagishi - San Jose CA, US
Wolf Zhang - Shanghai, CN
Alan Wu - Shanghai, CN
Wolf Zhang - Shanghai, CN
Alan Wu - Shanghai, CN
International Classification:
H02B 1/00
US Classification:
381123, 375238, 332109, 330 10
Abstract:
Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes a low distortion method of driving a switching amplifier comprising modulating an audio input signal to produce a half-wave rectified pulse-width modulated signal and a complementary half-wave rectified pulse-width modulated signal. These signals may be amplified in a power amplifier and combined in a feedback circuit to generate a first feedback signal and a second feedback signal, which may be coupled the inputs of a modulator for controlling the output signal.
Switching Supply Circuits And Methods
US Patent:
8441316, May 14, 2013
Filed:
Jan 6, 2011
Appl. No.:
12/985556
Inventors:
Hideto Takagishi - San Jose CA, US
Assignee:
Diodes Incorporated - Plano TX
International Classification:
H03F 3/217
US Classification:
330251, 330207 A, 330296
Abstract:
In one embodiment the present invention includes a switching circuit. The circuit comprises a first transistor, a second transistor, and a boost circuit. The first transistor couples a first power source to a first intermediate node during a first phase of operation and the second transistor couples a second intermediate node to the first intermediate node during a second phase of operation. The boost circuit is coupled to the second intermediate node and provides a second power source by a transferring of energy from the first power source. The transferring of energy includes an inductor receiving energy from the first power source during the first phase of operation and providing a portion of said energy to the boost circuit during the second phase of operation. The boost circuit provides a biasing to enable deactivation of the second transistor during the first phase of operation.
Low Distortion Switching Amplifier Circuits And Methods
US Patent:
7579910, Aug 25, 2009
Filed:
Jan 2, 2008
Appl. No.:
11/968379
Inventors:
Wolf Zhang - Shanghai, CN
Hideto Takagishi - San Jose CA, US
Alan Wu - Shanghai, CN
Hideto Takagishi - San Jose CA, US
Alan Wu - Shanghai, CN
Assignee:
PacificTech Microelectronics, Inc. - Grand Cayman
International Classification:
H03F 3/217
US Classification:
330251, 330 10, 330207 A
Abstract:
Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes an low distortion method of driving a switching amplifier comprising generating a first pulse width modulated signal on a first terminal, generating a second pulse width modulated signal on a second terminal, and delaying one of the first or second signals. In one embodiment, the modulated signals and delay result in pulse trains near zero crossings to reduce crossover distortion.
Variable Feedback Circuits And Methods
US Patent:
7256648, Aug 14, 2007
Filed:
Jun 24, 2005
Appl. No.:
11/166508
Inventors:
Hideto Takagishi - San Jose CA, US
Simon Tsai - Taipei County, TW
Simon Tsai - Taipei County, TW
Assignee:
PacificTech Microelectronics, Inc. - Grand Cayman
International Classification:
H03F 1/36
US Classification:
330 86, 330254, 330282
Abstract:
In one embodiment, the present invention includes a circuit comprising an amplifier having an input terminal, an output terminal, a positive supply voltage, and a negative supply voltage. The amplifier is configured to have a first gain. A variable feedback circuit is coupled between the input terminal and the output terminal. The difference between the voltage on the output terminal and input terminal is received by the variable feedback circuit, which changes the gain of the circuit and reduces distortion.