Abstract: Current sinking serial communication. At least one example is a packaged semiconductor product comprising: an input terminal electrically accessible on an exterior surface; an output terminal electrically accessible on an exterior surface; a digital memory disposed within the packaged semiconductor product and configured to store a digital word; a functional circuit coupled to the input terminal, the output terminal, and the digital memory, the functional circuit configured to perform a control function with respect to a signal on the input terminal, and the control function modifiable based on the digital word; a sense circuit coupled to the output terminal, the sense circuit configured to extract binary data provided as current pulses drawn through the output terminal; and a serial receiver coupled to the sense circuit, the serial receiver configured to accumulate the binary data into an updated digital word, and store the updated digital word to the digital memory.

Abstract: Current sinking serial communication. At least one example is a packaged semiconductor product comprising: an input terminal electrically accessible on an exterior surface; an output terminal electrically accessible on an exterior surface; a digital memory disposed within the packaged semiconductor product and configured to store a digital word; a functional circuit coupled to the input terminal, the output terminal, and the digital memory, the functional circuit configured to perform a control function with respect to a signal on the input terminal, and the control function modifiable based on the digital word; a sense circuit coupled to the output terminal, the sense circuit configured to extract binary data provided as current pulses drawn through the output terminal; and a serial receiver coupled to the sense circuit, the serial receiver configured to accumulate the binary data into an updated digital word, and store the updated digital word to the digital memory.

Abstract: A regulator circuit includes a first stage, a second stage, and a boost circuit. The first stage includes a reference input and a feedback input, the feedback input configured to receive feedback from an output of the regulator circuit. The second stage is coupled to the first stage. The second stage includes an output transistor configured to drive the output of the regulator circuit. The boost circuit includes a first transistor configured to generate a bias current based on an output current of the output transistor. The boost circuit further includes a current-to-voltage converter configured to generate a bias voltage based on the bias current, and a capacitive element coupled between the current-to-voltage converter and a node of the first stage.

Abstract: A system and method for controlling a low-dropout regulator (LDO) is disclosed. The system and method include a charge pump that is controlled to provide a charge pump voltage to power the LDO. The charge pump voltage can be adjusted relative to the LDO's input voltage to ensure efficient operation of the LDO for input voltages over a range. The charge pump is also controlled to limit the maximum charge pump voltage provided to ensure safe operation of the LDO. The system and method also include a under voltage lockout circuit that enables the LDO when it is determined that the charge pump voltage is sufficient to meet multiple criteria. For example, the charge pump voltage may be analyzed to determine if it is above a minimum voltage and if it is also sufficiently higher than the LDO's output voltage.

Abstract: A voltage pre-regulator can receive a variable voltage in a middle voltage range (e.g., dozens of volts) and provide a regulated voltage in a safe operating region of a low voltage device. The use of the voltage pre-regulator can allow circuits to use low voltage devices to perform additional regulation/conversion without fear of damage. The voltage pre-regulator disclosed herein can perform the voltage reduction and regulation functions of pre-regulation with commonly used transistor types because the disclosed circuits and method use a bias circuit. The bias circuit uses positive feedback so that no additional start-up circuitry is required. The positive feedback is controlled by negative feedback so that the pre-regulator is able to provide a regulated voltage that is stable over a range of input voltages and temperatures.

Abstract: A voltage pre-regulator can receive a variable voltage in a middle voltage range (e.g., dozens of volts) and provide a regulated voltage in a safe operating region of a low voltage device. The use of the voltage pre-regulator can allow circuits to use low voltage devices to perform additional regulation/conversion without fear of damage. The voltage pre-regulator disclosed herein can perform the voltage reduction and regulation functions of pre-regulation with commonly used transistor types because the disclosed circuits and method use a bias circuit. The bias circuit uses positive feedback so that no additional start-up circuitry is required. The positive feedback is controlled by negative feedback so that the pre-regulator is able to provide a regulated voltage that is stable over a range of input voltages and temperatures.

Abstract: Some applications require a noise filter to have a very low cutoff frequency. The low cutoff frequency can require the use of a large resistor that is not suitable for integration in an integrated circuit (IC) package. Smaller components can be used to provide a large resistance in a first direction but not in another. In other words, the resistance of these smaller components may be non-reciprocal. A non-reciprocal resistance can affect a response of the noise filter to disruptions at the input or the output. Additionally, these smaller components may not be suitable for low voltage operation. A noise filter is disclosed that provides a high resistance using components that can be included in an integrated circuit package. The noise filter has a reciprocal effective resistance and can utilize technology suitable for low voltage operation.

Abstract: Some applications require a noise filter to have a very low cutoff frequency. The low cutoff frequency can require the use of a large resistor that is not suitable for integration in an integrated circuit (IC) package. Smaller components can be used to provide a large resistance in a first direction but not in another. In other words, the resistance of these smaller components may be non-reciprocal. A non-reciprocal resistance can affect a response of the noise filter to disruptions at the input or the output. Additionally, these smaller components may not be suitable for low voltage operation. A noise filter is disclosed that provides a high resistance using components that can be included in an integrated circuit package. The noise filter has a reciprocal effective resistance and can utilize technology suitable for low voltage operation.

Abstract: A system and method for controlling a low-dropout regulator (LDO) is disclosed. The system and method include a charge pump that is controlled to provide a charge pump voltage to power the LDO. The charge pump voltage can be adjusted relative to the LDO's input voltage to ensure efficient operation of the LDO for input voltages over a range. The charge pump is also controlled to limit the maximum charge pump voltage provided to ensure safe operation of the LDO. The system and method also include a under voltage lockout circuit that enables the LDO when it is determined that the charge pump voltage is sufficient to meet multiple criteria. For example, the charge pump voltage may be analyzed to determine if it is above a minimum voltage and if it is also sufficiently higher than the LDO's output voltage.

Abstract: A system and method for controlling a low-dropout regulator (LDO) is disclosed. The system and method includes a charge pump that is controlled to provide a charge pump voltage to power the LDO. The charge pump voltage can be adjusted relative to the LDO's input voltage to ensure efficient operation of the LDO for input voltages over a range. The charge pump is also controlled to limit the maximum charge pump voltage provided to ensure safe operation of the LDO. The system and method also includes a under voltage lockout circuit that enables the LDO when it is determined that the charge pump voltage is sufficient to meet multiple criteria enable For example, the charge pump voltage may be analyzed to determine if it is above a minimum voltage and also sufficiently higher than the LDO's output voltage.

Abstract: A system and method for controlling a low-dropout regulator (LDO) is disclosed. The system and method includes a charge pump that is controlled to provide a charge pump voltage to power the LDO. The charge pump voltage can be adjusted relative to the LDO's input voltage to ensure efficient operation of the LDO for input voltages over a range. The charge pump is also controlled to limit the maximum charge pump voltage provided to ensure safe operation of the LDO. The system and method also includes a under voltage lockout circuit that enables the LDO when it is determined that the charge pump voltage is sufficient to meet multiple criteria enable For example, the charge pump voltage may be analyzed to determine if it is above a minimum voltage and also sufficiently higher than the LDO's output voltage.

Abstract: Circuits, methods, and system for DC voltage conversion are disclosed. A charge pump circuit is described that includes input switches and output switches that are individually controlled by different clock signals to alternatively couple energy storage capacitors to an input and to an output. The individualized switching control allows for the use of clock signals with no overlapping transitions to improve conversion efficiency. Additionally, the input switches are controlled by clock signals that are level shifted relative to the input voltage. The level shifted switching control also improves efficiency and allows for a range in input voltages to be accommodated for DC voltage conversion.