Abstract: A calibration operation determines a resistance of a sense resistor in a POE system. A voltage measurement is taken with a first current flowing through the sense resistor. A second voltage measurement is taken with a second current flowing through the resistor. A resistance value of the sense resistor is determined based on a voltage difference between the first and second voltage measurements and a current difference between the first current and the second currents.

Abstract: A calibration operation determines a resistance of a sense resistor in a POE system. A voltage measurement is taken with a first current flowing through the sense resistor. A second voltage measurement is taken with a second current flowing through the resistor. A resistance value of the sense resistor is determined based on a voltage difference between the first and second voltage measurements and a current difference between the first current and the second currents.

Abstract: A calibration operation determines a resistance of a sense resistor in a POE system. A voltage measurement is taken with a first current flowing through the sense resistor. A second voltage measurement is taken with a second current flowing through the resistor. A resistance value of the sense resistor is determined based on a voltage difference between the first and second voltage measurements and a current difference between the first current and the second currents.

Abstract: A technique for thermal management of a circuit includes generating a power consumption estimate for the circuit based on a predetermined update amount and a comparison of a sensed voltage level to a predetermined voltage level. The method includes generating a fault signal based on the power consumption estimate and a predetermined power consumption limit. Generating the power consumption estimate may include sensing a voltage drop across a first terminal of a device of the circuit and a second terminal of the device to generate the sensed voltage level. The sensed voltage level may be indicative of the voltage drop. The method may include updating the power consumption estimate by the predetermined update amount in response to a clock signal. The power consumption estimate may be used as a proxy for a measurement of a thermal state of the circuit.

Abstract: A technique for operating a driver includes enabling the driver to provide a first current through a first terminal of a driver device of the driver in a first mode of operation. The method includes sensing a voltage drop across the first terminal and a second terminal of the driver device to generate a sensed voltage level indicative of the voltage drop. The method includes generating a comparison output signal indicative of a comparison of the sensed voltage level to a threshold voltage level. The method includes selectively enabling the driver to provide a second current in a second mode of operation based on the comparison output signal. The first current may be less than the second current. The enabling may include enabling a first portion of the driver device using a first control signal, while a second portion of the driver device is disabled using a second control signal.

Abstract: A switch controls current to be supplied to an inductive load when turned on. A clamp circuit clamps a flyback voltage resulting from turning off the switch. The clamp circuit has a first clamping voltage responsive to the switch being turned off, and has a second clamping voltage, higher than the first clamping voltage, responsive to a current level through the inductive load being lower than a predetermined current level. That ensures that as the current comes down to levels required to break contact, the clamp voltage is increased to speed the collapse of the magnetic field when needed to minimize contact wear by maintaining armature momentum.

Abstract: A switch controls current to be supplied to an inductive load when turned on. A clamp circuit clamps a flyback voltage resulting from turning off the switch. The clamp circuit has a first clamping voltage responsive to the switch being turned off, and has a second clamping voltage, higher than the first clamping voltage, responsive to a current level through the inductive load being lower than a predetermined current level. That ensures that as the current comes down to levels required to break contact, the clamp voltage is increased to speed the collapse of the magnetic field when needed to minimize contact wear by maintaining armature momentum.

Abstract: A technique for thermal management of a circuit includes generating a power consumption estimate for the circuit based on a predetermined update amount and a comparison of a sensed voltage level to a predetermined voltage level. The method includes generating a fault signal based on the power consumption estimate and a predetermined power consumption limit. Generating the power consumption estimate may include sensing a voltage drop across a first terminal of a device of the circuit and a second terminal of the device to generate the sensed voltage level. The sensed voltage level may be indicative of the voltage drop. The method may include updating the power consumption estimate by the predetermined update amount in response to a clock signal. The power consumption estimate may be used as a proxy for a measurement of a thermal state of the circuit.

Abstract: A technique for operating a driver includes enabling the driver to provide a first current through a first terminal of a driver device of the driver in a first mode of operation. The method includes sensing a voltage drop across the first terminal and a second terminal of the driver device to generate a sensed voltage level indicative of the voltage drop. The method includes generating a comparison output signal indicative of a comparison of the sensed voltage level to a threshold voltage level. The method includes selectively enabling the driver to provide a second current in a second mode of operation based on the comparison output signal. The first current may be less than the second current. The enabling may include enabling a first portion of the driver device using a first control signal, while a second portion of the driver device is disabled using a second control signal.

Abstract: A circuit such as a subscriber line interface circuit (SLIC) has a multiple output power converter including an inductive converter, a first passive rectifier, a first capacitor, and a second passive rectifier. The inductive converter has a voltage input terminal for receiving an input voltage, and a voltage output terminal. The first passive rectifier has an input coupled to the voltage output terminal of the inductive power converter, and an output for providing a first power supply voltage. The first capacitor has a first terminal coupled to the output terminal of the inductive converter, and a second terminal. The second passive rectifier has an input coupled to the second terminal of the first capacitor, and an output terminal for providing a second power supply voltage different from the first power supply voltage.

Abstract: A circuit such as a subscriber line interface circuit (SLIC) has a multiple output power converter including an inductive converter, a first passive rectifier, a first capacitor, and a second passive rectifier. The inductive converter has a voltage input terminal for receiving an input voltage, and a voltage output terminal. The first passive rectifier has an input coupled to the voltage output terminal of the inductive power converter, and an output for providing a first power supply voltage. The first capacitor has a first terminal coupled to the output terminal of the inductive converter, and a second terminal. The second passive rectifier has an input coupled to the second terminal of the first capacitor, and an output terminal for providing a second power supply voltage different from the first power supply voltage.

Abstract: A method of generating a plurality of supply voltages for a plurality of subscriber line channels includes generating a first target VBAT value for a first associated linefeed driver from a first VBAT control. A second target VBAT value for a second associated linefeed driver is generated from a second VBAT control. A selected target VBAT value is generated based upon the first and second target VBAT values. A magnitude of the selected target VBAT value is not less than any maximum of a magnitude of the first and second target VBAT values. A switching regulator is controlled to provide a first generated VBAT corresponding to the selected target VBAT value, wherein the switching regulator provides a second generated VBAT having a pre-determined proportional relationship (p) to the first generated VBAT.

Abstract: A method of generating a plurality of supply voltages for a plurality of subscriber line channels includes generating a first target VBAT value for a first associated linefeed driver from a first VBAT control. A second target VBAT value for a second associated linefeed driver is generated from a second VBAT control. A selected target VBAT value is generated based upon the first and second target VBAT values. A magnitude of the selected target VBAT value is not less than any maximum of a magnitude of the first and second target VBAT values. A switching regulator is controlled to provide a first generated VBAT corresponding to the selected target VBAT value, wherein the switching regulator provides a second generated VBAT having a pre-determined proportional relationship (p) to the first generated VBAT.

Abstract: A method of controlling a switching regulator includes setting a current limit (ILIM) to a first value, ILIM1. An error voltage (VERR) is computed as a difference between an output voltage VOUT of the switching regulator and a reference voltage VREF of the switching regulator. The switching regulator current limit is set to a second value ILIM2, if the error voltage is greater than a first threshold voltage, VTH1. The switching regulator current limit is set to the first value, if the error voltage does not exceed a second threshold value, VTH2.