Power supplies for electronic devices (e.g. medical imaging devices) are disclosed herein. In one embodiment, a switched mode power supply is minimized in size and weight while maintaining efficiency and an artifact-free image using power supply design techniques tailored to increasing the power conversion frequency to be above the desired receive band of an ultrasound imaging system. In another embodiment, a switched mode power supply is minimized in size and weight while maintaining efficiency and an artifact-free image using power supply design techniques tailored to increasing the power conversion frequency to be just below the desired receive band of an ultrasound imaging system causing the third harmonic and possibly the second harmonic to fall just above the desired receive band.

An automatic gain control circuit includes a linear-to-log conversion circuit, a current amplifier circuit, and an amplitude sense circuit. The current amplifier circuit includes a current input terminal coupled to an output terminal of the linear-to-log conversion circuit. The amplitude sense circuit includes an input terminal coupled to an output terminal of the current amplifier circuit, and an output terminal coupled to a gain control input terminal of the current amplifier circuit.

Power supplies for electronic devices (e.g. medical imaging devices) are disclosed herein. In one embodiment, a switched mode power supply is minimized in size and weight while maintaining efficiency and an artifact-free image using power supply design techniques tailored to increasing the power conversion frequency to be above the desired receive band of an ultrasound imaging system. In another embodiment, a switched mode power supply is minimized in size and weight while maintaining efficiency and an artifact-free image using power supply design techniques tailored to increasing the power conversion frequency to be just below the desired receive band of an ultrasound imaging system causing the third harmonic and possibly the second harmonic to fall just above the desired receive band.

According to an embodiment, an operational amplifier includes a first amplifier stage coupled between an input node and an intermediate node, a second amplifier stage coupled between the intermediate node and an output node, a compensation capacitor having a first terminal coupled to the intermediate node and a second terminal, and a compensation amplifier coupled between the output node and the second terminal. The compensation amplifier has a positive gain greater than one.

Provided herein are amplifiers, such as buffers, with increased headroom. An amplifier stage includes a follower transistor and current source configured to receive a power supply voltage comprising an alternating current component and a direct current component. The alternating current component of the power supply voltage has substantially the same frequency and magnitude as the input signal received by the follower transistor. In radio frequency (RF) and intermediate frequency (IF) buffer applications, for example, the increased headroom can allow for linear buffering of an input signals with increased amplitude so that the output power one decibel (OP1dB) compression point can be increased.

A low distortion transconductance amplifier provides current to a grounded load using a virtual ground input stage, a pair of current mirrors, and a bias current source. The virtual ground input stage may include transistors arranged as a Darlington pair. The low distortion transconductance amplifier can function as a voltage-controlled AC current source that is operable at high frequencies.

A sensor device is provided including: an electric wire; a semiconductor device including an inductor and an amplifier, the inductor being configured to detect a magnetic field generated around the electric wire, the amplifier including a bipolar element configured to amplify a voltage generated at the inductor; and a substrate on which the first semiconductor device and the electric wire are arranged such that the first semiconductor device is apart from the electric wire by at least a given distance. In a plan view of the substrate, the electric wire does not overlap the first semiconductor device.

Voltage-to-current converters that include two current mirrors are disclosed. In an example voltage-to-current converter each current mirror is a complementary current mirror in that one of its input and output transistors is a P-type transistor and the other one is an N-type transistor. Such voltage-to-current converters may be implemented using bipolar technology, CMOS technology, or a combination of bipolar and CMOS technologies, and may be made sufficiently compact and accurate while operating at sufficiently low voltages and consuming limited power.

Voltage-to-current converters that include two current mirrors are disclosed. In an example voltage-to-current converter each current mirror is a complementary current mirror in that one of its input and output transistors is a P-type transistor and the other one is an N-type transistor. Such voltage-to-current converters may be implemented using bipolar technology, CMOS technology, or a combination of bipolar and CMOS technologies, and may be made sufficiently compact and accurate while operating at sufficiently low voltages and consuming limited power.

Voltage-to-current converters that include two current mirrors are disclosed. In an example voltage-to-current converter each current mirror is a complementary current mirror in that one of its input and output transistors is a P-type transistor and the other one is an N-type transistor. Such voltage-to-current converters may be implemented using bipolar technology, CMOS technology, or a combination of bipolar and CMOS technologies, and may be made sufficiently compact and accurate while operating at sufficiently low voltages and consuming limited power.