H03F2200/481

High efficiency current source/sink DAC

A current source and/or current sink digital-to-analog converter (DAC) includes a DAC circuit that converts a digital code to an analog current or voltage signal, an optional transconductance circuit that converts a voltage output of the DAC circuit into a current signal, and an output circuit that amplifies a current output of the DAC circuit or optionally amplifies a current output of the transconductance circuit to set a desired high current output for application to an output of the current source and/or current sink DAC. A power supply control current may be coupled to a power supply circuit that supplies power to the output circuit of the current source and/or current sink DAC. The power supply control current adjusts the output of the power supply circuit to cause the current source and/or current sink DAC to operate at a higher power efficiency.

CURRENT SENSE CIRCUIT HAVING A TEMPERATURE COMPENSATED RESPONSE

A package for a current sense circuit may include a lead-frame having a shunt resistance configured to generate a shunt voltage, which can be used to measure a current through the lead-frame. The shunt resistance associated with the lead-frame may be highly variable with temperature, which can cause errors in the current measurement. Accordingly, a current sense circuit can include an amplifier with an input resistor having a composite temperature coefficient configured to match a lead-frame temperature coefficient so that an output of the amplifier is compensated to remove variations in the shunt resistance of the lead-frame due to temperature.

Audio power source with improved efficiency

One example includes a differential amplifier, a voltage weighting element, coupled to a voltage source which provides an input voltage, to provide a reference voltage with a constant power limit when the input voltage varies, an error amplifier configured to receive and compare the reference voltage provided from the voltage weighting element and a feedback sensed voltage provided from the differential amplifier to identify whether the sensed voltage exceeds the reference voltage, and a pulse width modulation (PWM) controller, coupled to a power transformer and the error amplifier, that reduces a transformer input current provided to the power transformer based on the comparison of the reference voltage from the voltage weighting element and the feedback sensed voltage from the differential amplifier.

Voltage-to-current architecture and error correction schemes

Certain aspects of the present disclosure are generally directed to circuitry and techniques for voltage-to-current conversion. For example, certain aspects provide a circuit for signal amplification including a first amplifier; a first transistor, a gate of the first transistor being coupled to an output of the first amplifier and a drain of the first transistor being coupled to an output node of circuit; a first resistive element coupled between a first input node of the circuit and an input of the first amplifier; a second amplifier; a second transistor, a gate of the second transistor being coupled to an output of the second amplifier and a drain of the second transistor being coupled to the output node of circuit; and a second resistive element coupled between a second input node of the circuit and an input of the second amplifier.

COMMON-MODE COMPENSATION IN A MULTI-LEVEL PULSE-WIDTH MODULATION SYSTEM

A system for sensing an electrical quantity may include a sensing stage configured to sense the electrical quantity and generate a sense signal indicative of the electrical quantity, wherein the electrical quantity is indicative of an electrical signal generated by a Class-DG amplifier configured to drive a load wherein the Class-DG amplifier has multiple signal-level common modes and a common-mode compensator configured to compensate for changes to a common-mode voltage of a differential supply voltage of the driver occurring when switching between signal-level common modes of the Class-DG amplifier.

PROTECTION CIRCUIT IN ELECTRONIC DEVICE AND METHOD THEREFOR

An electronic device and method thereof of are provided to prevent burnout due to overcurrent. An electronic device includes a power amplifier configured to amplify a transmission signal; a battery configured to provide a bias voltage to the at least one power amplifier; and an overcurrent protection circuit configured to prevent overcurrent from flowing through the power amplifier. The overcurrent protection circuit includes a configurer configured to configure a reference current value, based on the power amplifier; a measurer configured to measure a bias current value due to the bias voltage; a comparator configured to compare the measured bias current value with the reference current value; and a controller configured to recognize overcurrent flowing through the power amplifier and control provision of the bias voltage, based on a result of the comparison.

HIGH FREQUENCY, HIGH OUTPUT IMPEDANCE AMPLIFIER FOR EMI ACTIVE FILTER APPLICATIONS
20220337226 · 2022-10-20 ·

A high-frequency amplifier for an active EMI filter with a symmetric class B emitter-follower output stage driven by a driver stage, with a sense output resistor. Both terminals of the sense resistor are brought to the noninverting, respecting inverting input of the driver stage through two dividers of the same ratio, in a global voltage feedback loop. The amplifier is configured to provide a high output impedance at 10 kHz and up to 100 MHz, a peak-to-peak output current of 2-10 ampere and a low quiescent current of less than 400 mA. The invention includes EMI filters with such a high-frequency current source, for example in the current-sense current-inject feedback configuration.

VOLTAGE-TO-CURRENT ARCHITECTURE AND ERROR CORRECTION SCHEMES

Certain aspects of the present disclosure are generally directed to circuitry and techniques for voltage-to-current conversion. For example, certain aspects provide a circuit for signal amplification including a first amplifier; a first transistor, a gate of the first transistor being coupled to an output of the first amplifier and a drain of the first transistor being coupled to an output node of circuit; a first resistive element coupled between a first input node of the circuit and an input of the first amplifier; a second amplifier; a second transistor, a gate of the second transistor being coupled to an output of the second amplifier and a drain of the second transistor being coupled to the output node of circuit; and a second resistive element coupled between a second input node of the circuit and an input of the second amplifier.

High Frequency Common Mode Rejection Technique for Large Dynamic Common Mode Signals
20170373655 · 2017-12-28 ·

A system is disclosed which allows for canceling high frequency rail to rail common mode swing at pulse-width modulation (PWM) frequency for a Class-D, H and G audio amplifier or a Linear Resonance Actuator (LRA) driver. This allows wide bandwidth current sensing without the need of external components, or large on-chip resistor-capacitor (RC) networks, facilitating integration of the sense resistor. In addition, the sense amplifier DC input common mode and audio band common mode swing is reduced, allowing a sense resistor high frequency common mode swing of a least twice the MOSFET gate break down voltages.

Ratiometric current-monitor sense resistance mismatch evaluation and calibration
11500406 · 2022-11-15 · ·

Current monitoring techniques are included in an electronic system that provides power to a load from a power output stage that supplies power to a load. Multiple current control devices form the power output stage in series with multiple sense resistors that provide corresponding sense voltages indicative of current provided through the multiple current control devices to the load in the same or different time intervals. A calibration control circuit controls injection of current through the multiple sense resistors individually and measures the corresponding sense voltages generated by the current to determine resistance values of the multiple sense resistors. A correction subsystem computes a first ratio of a first resistance to a second resistance and a second ratio of a third resistance to a fourth resistance of the multiple sense resistors, and controls compensation for a difference between the first ratio and the second ratio to remove the measurement error.