Patent application number | Description | Published |
20110163783 | NO POP SWITCH - A switch can be configured to receive a first signal at a first input and provide an output signal at an output, depending on a state of the switch. A switch state change can be delayed until an indication of a requested switch state different than a current switch state is received and the first signal reaches a threshold. | 07-07-2011 |
20110255203 | CHARGE PUMP SWITCH POWER DOWN PROTECTION - This application discusses, among other things, switch circuit apparatus having power down protection and not requiring power up sequencing. An apparatus embodiment can include a first supply node coupled to a first input of a level shifting circuit via a protection circuit, a second supply node coupled to a second input of the level shifting circuit via a single pull-up transistor, and a switch including a control input, a first node, and a second node controllably isolated from the first node, wherein the control input is coupled to the level shifting circuit. The first and second inputs of the level shifting circuit can be coupled via a rectifier, and the protection circuit can be configured to power the first and second supply nodes to controllably isolate the first and second nodes from each other when a voltage of one of the first or second nodes exceeds a threshold. | 10-20-2011 |
20110293100 | AUDIO AMPLIFIER PERFORMANCE WHILE MAINTAINING USB COMPLIANCE AND POWER DOWN PROTECTION - An apparatus comprises a first audio amplifier circuit configured to provide an analog audio signal and an analog switch circuit including a first input configured to receive the analog audio signal, a second input configured to receive a first digital data signal, and a first output configured to provide one of the digital data signal or the analog audio signal. The apparatus also includes a first feedback circuit coupled to the first audio amplifier circuit and the analog switch circuit output, the feedback circuit configured to bias the first audio amplifier circuit. | 12-01-2011 |
20120126864 | POWER-ON RESET - This document discusses, among other things, apparatus and methods for providing power-on reset (POR) functionality using an enable circuit. In an example, an apparatus can include a supply input configured to receive a supply voltage, an enable input configured to receive an enable signal, and an inversion network configured to control an enable output using the enable signal. The inversion network can include a delay element configured to delay a first transition of the enable output in response to a rising transition of the supply voltage. | 05-24-2012 |
20120126878 | STABLE ON-RESISTANCE SWITCH CIRCUIT - This document discusses, among other things, a compensation circuit configured to modulate a control voltage of a switch over a range of ambient temperatures during a conduction state of the switch to maintain a specified resistance between first and second nodes of the switch. The compensation circuit can include a temperature-insensitive resistor configured to provide a sense current, a current mirror configured to provide a mirror current using the sense current, and a temperature-sensitive resistor configured to provide the control voltage using the mirror current. | 05-24-2012 |
20120134516 | ENABLE AND DISABLE COMPARATOR VOLTAGE REFERENCE - This document discusses, among other things, systems and methods to reduce power use of an accessory detection device. The accessory detection device can be configured to be coupled to a mobile device having an audio jack configured to be coupled to a mobile device accessory having a send/end key. In an example, the accessory detection device can include a comparator and a switch. The comparator can be configured to receive mobile device accessory information from the mobile device accessory and to determine activation of the send/end key using the received mobile device accessory information. The switch can be configured to receive connection information indicative of mobile device accessory connection to the audio jack and to isolate a reference input of the comparator from a supply voltage using the connection information, for example, to reduce leakage current. | 05-31-2012 |
20120242397 | POWER DOWN ENABLED ANALOG SWITCH - This document discusses, among other things, apparatus and methods for passing a signal in a power down state. An example switch device can include a first depletion-mode transistor configured to pass an analog signal between a first node and a second node in a first state and to isolate the first node from the second node in a second state, a control circuit coupled to a control node of the first depletion-mode transistor and configured to isolate the control node from a first supply input in the first state and to couple the control node to the first supply input in the second state, and a tracking circuit configured to couple the control node of the first depletion-mode transistor to the first node during the first state and to isolate the control node of the first depletion-mode transistor from the first node in the second state. | 09-27-2012 |
20120306477 | RAIL TO RAIL COMPARATOR WITH WIDE HYSTERESIS AND MEMORY - An apparatus comprises an input to receive a voltage, a threshold voltage circuit, a comparison circuit, and an output. The threshold voltage circuit provides an adjustable first threshold voltage at a first output and an adjustable second threshold voltage at a second output. The comparison circuit determines when the input voltage is greater than the first voltage threshold, including when the first voltage threshold is adjusted substantially up to a high supply voltage rail, and determines when the input voltage is less than the second voltage threshold, including when the second voltage threshold is adjusted substantially down to a low supply voltage rail. The output provides a first indication when the input voltage is greater than the first voltage threshold and to provide a second indication when the input voltage is less than the second voltage threshold. | 12-06-2012 |
20130021046 | AUDIO JACK DETECTION CIRCUIT - This document discusses, among other things, a detection system configured to identify a type of a pole of a four-pole audio jack using first and second comparators. The detection system can include a bias circuit configured to bias a detection input coupled to the pole, and first and second comparators configured to compare the detection input to respective first and second thresholds to provide an indication of the type of the pole. | 01-24-2013 |
20130169255 | REGULATOR POWER-ON-RESET WITH LATCH - This document discusses, among other things, apparatus and methods for providing a power-on-reset signal. An example apparatus can include a regulator configured to receive a supply voltage and to provide a regulated voltage at an output, and a power-on-reset (POR) circuit including a POR comparator. The POR circuit can be configured to provide an indication that the regulated voltage is below a threshold level using an output of the POR comparator and to disable the POR comparator when the regulated voltage is above the threshold level. | 07-04-2013 |
20130257522 | HIGH INPUT VOLTAGE CHARGE PUMP - This document discusses, among other things, a charge pump circuit that includes an input, an output, a plurality of field effect transistors (FETs), each of the plurality FETs having a respective gate terminal, and at least two flying capacitors in electrical communication with at least one of the plurality of FETs. Each of the respective gate terminals is configured to receive a respective logic level shifted clock signal voltage. The at least two flying capacitors are configured to alternatingly charge and discharge in response to the logic level shifted clock signal voltages, and the at least two flying capacitors are configured to supply a voltage at the output that is different from a voltage at the input. | 10-03-2013 |
20130265184 | AUDIO DEVICE SWITCHING WITH REDUCED POP AND CLICK - This document discusses, among other things, apparatus and methods including an analog-to-digital controller (ADC) configured to receive an enable signal and to provide an ADC output signal to control logic, wherein the control logic is configured to provide a control voltage to a control input of a switch. In an example, the control voltage includes the ADC output signal when the ADC output signal is below a first threshold or above a second threshold. In certain examples, the control logic is configured to transition the control voltage from the first threshold to the second threshold when the ADC output signal is between the first and second thresholds. | 10-10-2013 |
20130292771 | METHOD AND APPARATUS FOR INTEGRATED CIRCUIT PROTECTION - In certain examples an integrated circuit protection circuit can include a circuit module, and an isolation device. The isolation device can be configured to couple a ground node of the circuit module to a power ground in an on state, and to isolate the ground node of the circuit module from the power ground in an off state, wherein the isolation module is configured to enter the off state when the IC receives a negative input voltage. | 11-07-2013 |
20130307591 | DEPLETION-MODE CIRCUIT - This document discloses, among other things, a switch circuit that includes a depletion-mode field-effect transistor (DMFET) having an ON-state and an OFF-state, wherein the DMFET is configured to couple a first node to a second node in the ON-state, and wherein the DMFET is configured to isolate the first node from the second node in the OFF-state, a negative charge pump that is coupled to a gate terminal of the DMFET, the charge pump configured to supply a negative charge pump voltage to the gate terminal of the DMFET, and a negative discriminator coupled to the charge pump, the discriminator configured to compare a first voltage at the first node and a second voltage at the second node and determine the negative charge pump voltage based on the comparison. | 11-21-2013 |
20140098297 | NO POP SWITCH - A switch can be configured to receive a first signal at a first input and provide an output signal at an output, depending on a state of the switch. A switch state change can be delayed until an indication of a requested switch state different than a current switch state is received and the first signal reaches a threshold. | 04-10-2014 |
20140132311 | HIGH-VOLTAGE BULK DRIVER - This application discusses, among other things, apparatus and methods for driving the bulk of a high-voltage transistor using transistors having gates with low-voltage ratings. In an example, a bulk driver can include an output configured to couple to bulk of a high-voltage transistor, a pick circuit configured to couple the output to an input voltage at an input terminal of the high-voltage transistor or an output voltage at the output terminal of the high-voltage transistor when the high-voltage transistor is in a high impedance state, and a bypass circuit configured to couple the output of the bulk driver to the output voltage when the high-voltage transistor is in a low impedance state. | 05-15-2014 |
20140177876 | AUDIO AMPLIFIER PERFORMANCE WHILE MAINTAINING USB COMPLIANCE AND POWER DOWN PROTECTION - An apparatus comprises a first audio amplifier circuit configured to provide an analog audio signal and an analog switch circuit including a first input configured to receive the analog audio signal, a second input configured to receive a first digital data signal, and a first output configured to provide one of the digital data signal or the analog audio signal. The apparatus also includes a first feedback circuit coupled to the first audio amplifier circuit and the analog switch circuit output, the feedback circuit configured to bias the first audio amplifier circuit. | 06-26-2014 |
20140323184 | REVERSE CURRENT BLOCKING COMPARATOR - An apparatus comprises at least one transistor configured as analog switch, a well biasing circuit configured to provide a dynamic electrical bias to a bulk region of the at least one transistor, and a comparator circuit in electrical communication with the well biasing circuit and the transistor. The comparator circuit is configured to detect a first operating condition of the transistor and a second operating condition of the transistor. The well biasing circuit is configured to apply a first electrical bias to the bulk region of a transistor when the first operating condition is detected and apply a second electrical bias to the bulk region of the transistor when the second operating condition is detected, and wherein the comparator is configured to apply hysteresis to detection of the first and second operating conditions. | 10-30-2014 |