A current sensing circuit includes a filtering circuit, an amplifier, a first resistor, a first transistor and a second transistor. The filtering circuit is coupled to two terminals of a sensing resistor. The amplifier has a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to the filtering circuit. The first resistor is coupled between the filtering circuit and the first input terminal of amplifier. A control terminal of the first transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the first input terminal of amplifier and its second terminal is grounded through a second resistor. A control terminal of the second transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the second input terminal of amplifier and its second terminal is grounded through a third resistor.

A current sensing circuit includes a filtering circuit, an amplifier, a first resistor, a first transistor and a second transistor. The filtering circuit is coupled to two terminals of a sensing resistor. The amplifier has a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to the filtering circuit. The first resistor is coupled between the filtering circuit and the first input terminal of amplifier. A control terminal of the first transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the first input terminal of amplifier and its second terminal is grounded through a second resistor. A control terminal of the second transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the second input terminal of amplifier and its second terminal is grounded through a third resistor.

A musical instrument preamplifier includes a n-type JFET and a pnp current mirror connected to the drain side of the JFET. The pnp current mirror includes two pnp transistors. The current mirror is configured to control the current to independently set the operating point of the JFET and the output. An npn transistor is connected to one of the pnp transistors of the current mirror to form an inverted Sziklai pair. An auto-bias network is connected between the npn and pnp transistors that form the Sziklai pair.

Circuits and methods for maintaining loop stability and good load regulation in low loop gain LDO regulator circuits. Embodiments encompass LDO regulator circuits that include an offset error correction circuit that generates an opposing voltage V.sub.OFFSET as a function of load current to substantially cancel out variations in V.sub.OUT that would otherwise occur due to load regulation limitations of the LDO regulator circuits. Embodiments use V.sub.OFFSET to imbalance currents in differential paths in a last-stage LDO error-amplifier so that an offset is propagated to a pair of inputs to the error-amplifier, thereby altering the output voltage V.sub.OUT to a corrected value. Benefits include improved LDO load regulation even when feedback loop gain is low, the available of both digital and analog implementations, high LDO accuracy and less variation of the output voltage V.sub.OUT, and suitability for implementation in integrated circuits for applications such as high precision power supplies.

Described embodiments include an integrated circuit for temperature gradient compensation of a bandgap voltage. A bandgap core circuit has a bandgap feedback input, a bandgap adjustment input and a bandgap reference output. A resistor is coupled between the bandgap adjustment input and a ground terminal. An offset and slope correction circuit has an offset correction output that is coupled to the bandgap adjustment input. A signal at the offset correction output is trimmed at an ambient temperature. A thermal error cancellation (TEC) circuit has a TEC output coupled to the bandgap adjustment input. The TEC circuit includes first and second temperature sensors that are located apart from each other. A signal at the TEC output is responsive to temperatures at the first and second temperature sensors. An amplifier has an amplifier input and an amplifier output. The amplifier input is coupled to the bandgap reference output.

According to one embodiment, a transimpedance circuit includes: a transimpedance amplifier that converts a current signal into a voltage signal, a reference voltage generating circuit that generates a reference voltage signal, and a comparator that generates a pulse signal corresponding to the current signal in accordance with a voltage level of the voltage signal and a voltage level of the reference voltage signal. The transimpedance amplifier includes a first transistor that amplifies the current signal, a voltage converter that converts the current signal into a voltage signal, and a bypass circuit that allows the current signal to be bypassed when the current signal which flows through a control terminal of the first transistor exceeds a predetermined value.

An electric circuit according to one embodiment of the present technology includes a target circuit and an auxiliary circuit. The target circuit includes an output portion from which predetermined output power is output, and an application point to which a voltage corresponding to the output power is applied to output the output power. The auxiliary circuit has impedance lower than impedance of the target circuit, and outputs the voltage corresponding to the output power to the application point as an auxiliary voltage.

Circuits and methods for maintaining loop stability and good load regulation in low loop gain LDO regulator circuits. Embodiments encompass LDO regulator circuits that include an offset error correction circuit that generates an opposing voltage V.sub.OFFSET as a function of load current to substantially cancel out variations in V.sub.OUT that would otherwise occur due to load regulation limitations of the LDO regulator circuits. Embodiments use V.sub.OFFSET to imbalance currents in differential paths in a last-stage LDO error-amplifier so that an offset is propagated to a pair of inputs to the error-amplifier, thereby altering the output voltage V.sub.OUT to a corrected value. Benefits include improved LDO load regulation even when feedback loop gain is low, the available of both digital and analog implementations, high LDO accuracy and less variation of the output voltage V.sub.OUT, and suitability for implementation in integrated circuits for applications such as high precision power supplies.

Described herein are systems and methods that can adjust the performance of a transimpedance amplifier (TIA) in order to compensate for changing environmental and/or manufacturing conditions. In some embodiments, the changing environmental and/or manufacturing conditions may cause a reduction in beta of a bipolar junction transistor (BJT) in the TIA. A low beta may result in a high base current for the BJT causing the output voltage of the TIA to be formatted as an unusable signal output. To compensate for the low beta, the TIA generates an intermediate signal voltage, based on the base current and beta that is compared with the PN junction bias voltage on another BJT. Based on the comparison, the state of a digital state machine may be incremented, and a threshold base current is determined. This threshold base current may decide whether to compensate the operation of the TIA, or discard the chip.

An ultrasound detection device includes a probe and a transceiver. The probe includes first and second transducers, and an amplifier circuit. The first transducer transmits ultrasound. The second transducer includes a first electrode connected to a first wire, and converts the ultrasound into an electrical signal. The amplifier circuit includes first and second transistors. The first transistor includes a third electrode connected to the first wire, a fourth electrode as a gate or a base connected to a second electrode of the second transducer, and a fifth electrode connected to the fourth electrode via a resistor and connected to a second wire via a resistor. The second transistor includes an electrode connected to the first wire, an electrode as a gate or a base connected to the fifth electrode, and an electrode connected to the second wire via a resistor and connected to the second wire via a capacitor.