Abstract: A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

Abstract: A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

Abstract: In an example, a circuit includes an input stage having a control voltage input, a feedback input, a first control output and a second control output. The feedback input is coupled to a driver output. A first path stage has a first voltage input and a third output. The first voltage input is coupled to the first control output, and the third output is coupled to the driver output. A second path stage has a second voltage input and a fourth output. The second voltage input is coupled to the second control output, and the fourth output is coupled to the driver output. A load transistor has a control input coupled to the driver output. The input stage is configured to provide gm-boosting to the first path stage to turn on the load transistor responsive to an output voltage at a voltage output.

Abstract: A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

Abstract: A circuit includes a rectifier, a charge pump, and a clamp control circuit. The rectifier has an input configured to be coupled to an alternating current (AC) power source. The rectifier rectifies an AC signal from the AC power source to produce a rectified voltage on a first voltage node. The rectifier includes a first transistor coupled to a ground node and to the input. The first switch has a first control input. The charge pump is coupled to the first voltage node. The charge pump is configured to generate a second voltage on a second voltage node. The voltage regulator is coupled to the second voltage node. The clamp control circuit is coupled to the first and second voltage nodes and has an output node coupled to the first control input.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to control switching of a sampling circuit. An example apparatus includes an offset window detector to determine whether a first voltage meets a first threshold of a target input voltage; a settling time detector coupled to the offset window detector, the settling time detector to determine whether a second voltage meets a second threshold, the second voltage dependent on a delay of the settling time detector, the delay of the settling time detector to track a time response of a scaling amplifier; and a sample acquisition controller coupled to the offset window detector and the settling time detector, the sample acquisition controller operable to cause a reference voltage to be sampled, in response to the first threshold and the second threshold being met.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to control switching of a sampling circuit. An example apparatus includes an offset window detector to determine whether a first voltage meets a first threshold of a target input voltage; a settling time detector coupled to the offset window detector, the settling time detector to determine whether a second voltage meets a second threshold, the second voltage dependent on a delay of the settling time detector, the delay of the settling time detector to track a time response of a scaling amplifier; and a sample acquisition controller coupled to the offset window detector and the settling time detector, the sample acquisition controller operable to cause a reference voltage to be sampled, in response to the first threshold and the second threshold being met.

Abstract: A system includes a clamp circuit configured to regulate a converter input supply voltage based on control signals. The system also includes a converter configured to the adjust the converter input supply voltage to a converter output supply voltage. The system also includes a controller configured to adjust the control signals for the clamp circuit using a first mode based on the converter output supply voltage and a second mode based on the converter input supply voltage.

Abstract: A system includes a clamp circuit configured to regulate a converter input supply voltage based on control signals. The system also includes a converter configured to the adjust the converter input supply voltage to a converter output supply voltage. The system also includes a controller configured to adjust the control signals for the clamp circuit using a first mode based on the converter output supply voltage and a second mode based on the converter input supply voltage.

Abstract: A circuit includes a rectifier, a charge pump, and a clamp control circuit. The rectifier has an input configured to be coupled to an alternating current (AC) power source. The rectifier rectifies an AC signal from the AC power source to produce a rectified voltage on a first voltage node. The rectifier includes a first transistor coupled to a ground node and to the input. The first switch has a first control input. The charge pump is coupled to the first voltage node. The charge pump is configured to generate a second voltage on a second voltage node. The voltage regulator is coupled to the second voltage node. The clamp control circuit is coupled to the first and second voltage nodes and has an output node coupled to the first control input.

Abstract: A method for driving a piezoelectric transducer is provided. An input signal is received. At least one of a plurality of modes is selected for a buck-boost stage from a comparison of a desired voltage on a capacitor to a first threshold and a second threshold, where the desired voltage is determined from the input signal. The piezoelectric transducer is then driven substantially within the audio band using the desired voltage on the capacitor using an H-bridge that changes state with each zero-crossing.

Abstract: A method for driving a piezoelectric transducer is provided. An input signal is received. At least one of a plurality of modes is selected for a buck-boost stage from a comparison of a desired voltage on a capacitor to a first threshold and a second threshold, where the desired voltage is determined from the input signal. The piezoelectric transducer is then driven substantially within the audio band using the desired voltage on the capacitor using an H-bridge that changes state with each zero-crossing.