A data output device is provided. The data output device includes a converter circuit configured to generate a conversion signal based on an output signal; a boosting circuit configured to generate a boosting signal based on the output signal; and an output circuit configured to generate the output signal based on an input signal and a feedback signal, the feedback signal being based on the conversion signal and the boosting signal.

An amplifier circuit includes an amplifier and a bias circuit. The bias circuit includes a bias transistor having a base terminal and a collector terminal, a transistor having a gate terminal, a source terminal, and a drain terminal, a transistor having a gate terminal, a source terminal, and a drain terminal, resistors, and a current source. The source terminals are connected to a power source. One end portion of the resistor is connected to the base terminal, the other end portion of the resistor is connected to the drain terminal, one end portion of the resistor is connected to the other end portion of the resistor, the other end portion of the resistor is connected to the bias output terminal, and the bias circuit further includes a feedback circuit that controls the electric potential of the base terminal based on the electric potential of the collector terminal.

A bipolar amplification circuit has a control amplifier (101), a dependent current source (102) configured to supply current to an output terminal (104) and driven by an output from the control amplifier (101). A dependent current sink (103) is configured to receive current from the output terminal (104) and is also driven by the output from the control amplifier (101). The control amplifier includes an inverting input (105) and an input signal is supplied to this inverting input. A negative feedback signal of a first polarity is supplied to the inverting input from said dependent current source and a negative feedback signal of a second polarity is supplied to said inverting input from said dependent current sink.

A semiconductor device includes input and output terminals, first and second power supply terminals, first and second transistors, and a first resistance element. In the first transistor, gate and source terminals are respectively connected to the input terminal and the first power supply terminal, a drain terminal is connected to the second power supply terminal in direct current and to the output terminal, and the gate and drain terminals are connected via the first resistance element. In the second transistor, a source terminal is connected to the first power supply terminal, and gate and drain terminals are short-circuited at a node connected to the gate terminal of the first transistor in direct current. In a lower frequency region, an impedance of the first resistance element is lower than impedances of parasitic capacitances in the first transistor between the gate and drain terminals and between the gate and source terminals.

A method and apparatus are described for bio-impedance measurement using voltage to current conversion. In one example, a bio-impedance transducer includes an input stage to receive a bio-impedance signal having an oscillating voltage from two electrodes, the electrodes being coupled to a body, a resistance across the two electrodes to determine an alternating current of the bio-impedance signal, a gain stage coupled to the resistance to amplify the alternating current, a down converter coupled to the gain stage to convert the amplified alternating current to a direct current bio-impedance signal, and an analog-to-digital converter coupled to the down converter to convert the direct current bio-impedance signal to a digital bio-impedance signal.

A current-bootstrap comparator includes a receiving unit, a first current generation unit and a second current generation unit. The receiving unit receives a load voltage signal, a low threshold voltage and a high threshold voltage. The first current generation unit generates a first current. The second current generation unit generates a second current having a magnitude substantially same as a magnitude of the first current and a direction reverse to the first current. The first current and the second current are supplied to a next-stage circuit as a source current and a corresponding sink current, respectively, when the level of the load voltage signal is higher than the high threshold voltage or lower than the low threshold voltage. The magnitudes of the first current and the second current substantially equal zero when the level of the load voltage signal is between the high threshold voltage and the low threshold voltage.

A radio frequency (RF) power amplifier includes an amplifying stage that includes an amplifying module, an input module and a feedback module. The amplifying module receives an RF to-be-amplified signal, and performs power amplification on the RF to-be-amplified signal to generate an RF output signal. The input module receives an RF input signal. The feedback module receives the RF output signal, cooperates with the input module to provide the RF to-be-amplified signal based on the RF input and output signals, and cooperates with the amplifying module to forma positive feedback loop that provides a loop gain which is less than one.

A low noise amplifying system with adjustable gain. The low noise amplifier includes a plurality of gain stages, including a first stage and a last stage each having fixed gain, and an intermediate stage having adjustable gain. The intermediate stage is an inverting gain stage that includes a field effect transistor connected from the output to the input, to provide negative feedback, reducing the gain as a control voltage (applied to the gate of the field effect transistor) is adjusted to decrease the channel resistance of the field effect transistor. A control circuit measures the input and output signal power of the amplifying system and adjusts the gain of one or more intermediate stages to trade off linearity against noise figure.

A low noise amplifier (LNA) includes a pair of n-type transistors, each configured to provide a first transconductance; a pair of p-type transistors, each configured to provide a second transconductance; a first pair of coupling capacitors, cross-coupled between the pair of n-type transistors, and configured to provide a first boosting coefficient to the first transconductance; and a second pair of coupling capacitors, cross-coupled between the pair of p-type transistors, and configured to provide a second boosting coefficient to the second transconductance, wherein the LNA is configured to use a boosted effective transconductance based on the first and second boosting coefficients, and the first and second transconductances to amplify an input signal.

One or more systems, devices and/or methods of use provided herein relate to a baseband filter that can be used in a current-mode end-to-end signal path. The current-mode end-to-end signal path can include a digital to analog converter (DAC) operating in current-mode and an upconverting mixer, operating in current-mode and operatively coupled to the DAC. In one or more embodiments, a device used in the signal path can comprise a baseband filter that receives an input current and outputs an output current. The baseband filter can comprise a feedback loop component having an active circuit branch and a passive circuit branch coupled in a loop. A mirroring device can be coupled to the feedback loop component and can provide an output of the device. Selectively activating the mirroring device can vary gain, such as of the mirroring device.