Abstract: The objective of the invention is to provide an A/D converter that exhibits fewer malfunctions due to variations in manufacturing.

Abstract: The objective of the invention is to provide an A/D converter that exhibits fewer malfunctions due to variations in manufacturing.

Abstract: A sequential comparison-type analog-to-digital converter (ADC) that has improved precision and which is capable of high-speed operation is disclosed, the analog-to-digital converter comprising a digital-to-analog converter that outputs a plurality of different reference analog signals according to a multibit digital signal, a plurality of comparators that compare an input analog signal with the plurality of reference analog signals, and a sequential comparison control circuit that changes bit values of the multibit digital signal in order from higher bits so that at least one of the plurality of reference analog signals becomes closer to the input analog signal and decides the bit values in order from higher bits based on the comparison results and at the same time, correcting the decided higher bit values, wherein the sequential comparison control circuit decides the bit values of the multibit digital signal down to a predetermined bit based on the comparison results of the plurality of comparators and at th

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A sequential comparison-type analog-to-digital converter (ADC) that has improved precision and which is capable of high-speed operation is disclosed, the analog-to-digital converter comprising a digital-to-analog converter that outputs a plurality of different reference analog signals according to a multibit digital signal, a plurality of comparators that compare an input analog signal with the plurality of reference analog signals, and a sequential comparison control circuit that changes bit values of the multibit digital signal in order from higher bits so that at least one of the plurality of reference analog signals becomes closer to the input analog signal and decides the bit values in order from higher bits based on the comparison results and at the same time, correcting the decided higher bit values, wherein the sequential comparison control circuit decides the bit values of the multibit digital signal down to a predetermined bit based on the comparison results of the plurality of comparators and at th

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: An analog-to-digital converter has a digital-to-analog converter, first, second and third comparators, and a sequential comparison register and control logic circuit. The digital-to-analog converter produces analog signals, the first, second and third comparators compare the input analog signal with first, second and third analog signals which are different from each other. Further, the sequential comparison register and control logic circuit controls the digital signals that are fed to the digital-to-analog converter from the first to third comparators, and outputs the digital signals as digital values obtained by subjecting the input analog signals to the analog-to-digital conversion.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: An analog-to-digital converter has a digital-to-analog converter, first, second and third comparators, and a sequential comparison register and control logic circuit. The digital-to-analog converter produces analog signals, the first, second and third comparators compare the input analog signal with first, second and third analog signals which are different from each other. Further, the sequential comparison register and control logic circuit controls the digital signals that are fed to the digital-to-analog converter from the first to third comparators, and outputs the digital signals as digital values obtained by subjecting the input analog signals to the analog-to-digital conversion.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: A high frequency power amplifier module is provided for improving output controllability. A wireless communication apparatus incorporates a high frequency power amplifier module in a multi-stage configuration including a plurality of cascaded MOSFETS. The power amplifier module comprises a bias circuit for generating a gate voltage in response to a power control voltage (vapc) generated based on a power control signal of the wireless communication apparatus. The gate voltage has a bias pattern which presents smaller fluctuations in output power in response to a control voltage (Vapc) in a region near a threshold voltage (Vth) of the MOSFETs in respective amplification stages. In this way, the controllability for the output power is improved. More specifically, the power amplifier module has a gate bias circuit for generating the gate voltage (Vg) which follows a gate voltage pattern.

Abstract: Making use of a digital acoustic signal processing apparatus arranged by employing memory device for storing a digital acoustic signal, acoustic frequency feature enhancing device for enhancing an acoustic frequency feature, and low-speed sound reproducing device for changing a speed of the stored voice to reproduce this voice as a low speed into a hearing aid and an appliance with an acoustic output, a hearing function difficulty due to an age is aided in utilization of audio output appliances such as a hearing aid, television receiver, and a telephone receiver. After the voice has been stored in the memory device, a process for enhancing the frequency characteristic in order to fit the frequency characteristic to the individual hearing characteristic and the voice reproducing environment is carried out and thereafter represented to the user. The user can repeatedly listen the voice stored in the memory device with employment of control device for controlling the voice reproducing operation.

Abstract: A bus driving system includes n bus wires having data signal wires and control signal wires, (n-1) switching circuits constituting driver circuits at a transmitting end, a precharge circuitry for precharging (n-2) bus wires and (n-1)-th bus wire with a control circuit for redistributing wire capacitances of transmission lines formed by the bus wires, and a predischarge circuitry for predischarging n-th bus wire. The switching circuits control conduction and non-conduction between (n-2) bus wires, (n-1)-th bus wire and n-th bus wire, wherein the (n-2) switching circuits respond to (n-2) bit signals and a control signal, while the (n-1)-th switching circuit responds to the control signal. The signal from the transmitting end is detected by a detection circuit at a receiving end via the transmission lines.

Abstract: Making use of a digital acoustic signal processing apparatus arranged by employing memory device for storing a digital acoustic signal, acoustic frequency feature enhancing device for enhancing an acoustic frequency feature, and low-speed sound reproducing device for changing a speed of the stored voice to reproduce this voice as a low speed into a hearing aid and an appliance with an acoustic output, a hearing function difficulty due to an age is aided in utilization of audio output appliances such as a hearing aid, television receiver, and a telephone receiver. After the voice has been stored in the memory device, a process for enhancing the frequency characteristic in order to fit the frequency characteristic to the individual hearing characteristic and the voice reproducing environment is carried out and thereafter represented to the user. The user can repeatedly listen the voice stored in the memory device with employment of control device for controlling the voice reproducing operation.

Abstract: In a mobile wireless communication end device having an electric power source including a cell, and a signal processing part and a transmitting-receiving part, to which electric power is applied from the electric power source, operation is performed in operation mode selected previously by the user when voltage of the electric power source is dropped. The signal processing part and the transmitting-receiving part have a normal operation mode operating at normal electric power and a low power operation mode operating at electric power lower than the normal operation mode.

Abstract: A signal processing apparatus for converting an analog signal to a digital signal and processing the digital signal. In particular, a digital filter for performing processing at high speed is implemented by using an integrated circuit of low power consumption. The signal processing apparatus includes a circuit for comparing an input analog signal with each voltage of a plurality of analog reference voltages and generating a thermometer code Tc depending upon the analog input signal, a decoder for detecting a change point of the thermometer code Tc, and a plurality of memory circuits having output signal lines of the decoder as word selection lines. The product of an input signal value corresponding to each word selection line and a predetermined filter coefficient is stored in the corresponding word of the memory circuits. The memories are used as look-up tables.