According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Low-power, high-performance voltage regulator circuit devices are disclosed and described. In one embodiment, such a device can include a first stage circuitry configured to generate a high voltage reference from a low voltage reference, a second stage circuitry coupled to the first stage circuitry, the second stage circuitry configured to receive the high voltage reference and output a voltage regulated signal, and a switch disposed between and coupled to the first stage circuitry and the second stage circuitry, the switch being configured to couple and uncouple the first stage circuitry from the second stage circuitry.

An amplifier circuit, for a capacitive acoustic transducer defining a sensing capacitor that generates a sensing signal as a function of an acoustic signal, has a first input terminal and a second input terminal, which are coupled to the sensing capacitor and: a dummy capacitor, which has a capacitance corresponding to a capacitance at rest of the sensing capacitor and a first terminal connected to the first input terminal; a first amplifier, which is coupled at input to the second input terminal and defines a first differential output of the circuit; a second amplifier, which is coupled at input to a second terminal of the dummy capacitor and defines a second differential output of the circuit; and a feedback stage, which is coupled between the differential outputs and the first input terminal, for feeding back onto the first input terminal a feedback signal, which has an amplitude that is a function of the sensing signal and is in phase opposition with respect thereto.

A fingerprint sensing circuit and a fingerprint sensing apparatus are provided. The fingerprint sensing circuit includes a sensing electrode; a first converting circuit connected to the sensing electrode and configured to convert a coupling capacitance sensed by the sensing electrode into a drive voltage, where the drive voltage is equal to a sum of a voltage variation converted from the coupling capacitance and a reference voltage; and a second converting circuit configured to generate a sensing current based on the drive voltage, and send the sensing current to a fingerprint signal processor, where the sensing current is equal to a product of a transconductance gain of the second converting circuit and the voltage variation, and the fingerprint signal processor performs fingerprint sensing based on the sensing current. With the fingerprint sensing circuit and the fingerprint sensing apparatus, the detection accuracy can be improved.

High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

An integrated circuit (IC) device includes a controller circuitry having an input coupled to a photodiode of an optoelectronic circuitry and an output coupled to a heater of the optoelectronic circuitry, the controller circuitry configured to determine a center frequency of the optoelectronic circuitry based on a shape of an input signal received from the photodiode, and provide a heater signal to the heater based on the shape of the input signal and the center frequency of the optoelectronic circuitry.

In an example, a circuit includes a high side output transistor having a control terminal coupled to a first capacitor, and includes a low side output transistor having a control terminal coupled to a second capacitor and a balancing capacitor. The circuit includes a first differential input stage configured to receive a differential input and provide a first output current to the control terminal of the high side output transistor. The circuit includes a second differential input stage configured to receive the differential input and provide a second output current to the control terminal of the low side output transistor. The circuit includes a floating battery coupled to the control terminal of the high side output transistor and the control terminal of the low side output transistor. The balancing capacitor balances a gate-to-source capacitance of the low side output transistor with a gate-to-source capacitance of the high side output transistor.

Embodiments of equalizers are disclosed. In an embodiment, an equalizer includes a first signal path segment that includes a first plurality of serially connected transistors and current sources, a second signal path segment that includes a second plurality of serially connected transistors and current sources, and at least one termination resistor connected to the first and second signal path segments. The first plurality of serially connected transistors and current sources includes a first current source and a second current source connectable to a reference voltage and a first transistor and a second transistor connected between input terminals of the equalizer and the first and second current sources, where the first signal path segment further includes at least one resistor connected between the first and second current sources.

Provided is a phase array receiver. A phase array receiver according to an embodiment of the present invention includes a plurality of antennas, a plurality of low-noise amplifiers, a plurality of phase shifters, a plurality of transconductors, and a frequency mixer. A plurality of low-noise amplifiers amplify RF signals received from the plurality of antennas. The plurality of phase shifters adjusts the phase of the RF signals to generate a plurality of RF phase adjustment signals. The plurality of transconductors convert a plurality of RF phase adjustment signals into a plurality of RF current signals based on the gain control signal. The frequency mixer converts a sum of the plurality of RF current signals into a mixed current signal. According to the inventive concept, the linearity of the signal processing may be improved and the area for the implementation of the phase array receiver may be reduced.

In a sensor reader, an IC chip has a function for amplifying and outputting a sensor signal from each sensor element included in a sensor array, and includes a plurality of channel amplifiers connected each of the sensor elements. When an output switch is closed and the IC chip is in the outputting state, channel switches operate sequentially, and sensor amplification signals are output sequentially from the channel amplifiers. When the output switch is open and the IC chip is in the non-outputting state, a bias current of an operational amplifier of the channel amplifier is decreased, the IC chip is set to a low power consumption state, and gain of the operational amplifier is decreased.