RMS-to-DC converter with fault detection and recovery
AssigneeLinear Technology Corporation
InventorJoseph Gerard Petrofsky
Life of this patent
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Abstract
A circuit that provides the root-mean-square (RMS) value of an input signal and that detects and independently recovers from an output fault condition is provided. The circuit includes reconfigurable circuitry that changes from normal operating mode to fault recovery mode when an output fault is detected. During fault recovery mode, the circuit provides a modified output signal that allows independent recovery from an output fault condition. Once recovery is complete, the circuit returns to normal operating mode and provides a DC output signal proportional to the RMS value of an AC input signal.
Claims41
A circuit for providing an output signal proportional to a root-mean-square (RMS) value of an input signal that is capable of detecting and independently recovering from an output fault condition, the circuit comprising:
- a pulse code modulator circuit including a reconfigurable circuit coupled to an input node and an output node that may be reconfigured as a first delta-sigma modulator circuit and a comparator circuit;
- and
- a demodulator circuit including a first multiplying digital to analog converter (MDAC) circuit.
A circuit for providing an output signal at an output node proportional to a root-mean-square (RMS) value of an input signal at an input node, wherein the circuit is capable of detecting and independently recovering from a fault condition and includes a first delta-sigma modulator and a second delta-sigma modulator, the circuit comprising:
- a reconfigurable circuit coupled to the input node and the output node;
- the second delta-sigma modulator coupled to the output node and a first output of the reconfigurable circuit;
- and
- a monitor circuit coupled to a second output of the reconfigurable circuit and a first output of the second delta-sigma modulator, wherein the monitor circuit monitors one of the outputs from the group consisting of the following:
- 1) the output of the reconfigurable circuit when the reconfigurable circuit is configured as the first delta-sigma modulator to detect when the fault condition exists, and 2) the output of the second delta-sigma modulator when the reconfigurable circuit is configured as a comparator to detect when the circuit recovers from the fault condition.
A circuit for providing an output signal at an output node proportional to a root-mean-square (RMS) value of an input signal at an input node, wherein the circuit is capable of detecting and independently recovering from a fault condition, the circuit comprising:
- a reconfigurable circuit coupled to the input node and the output node;
- and
- a monitor circuit coupled to an output of the reconfigurable circuit to detect a fault condition, wherein the reconfigurable circuit comprises an amplifier, a comparator, a plurality of capacitors, and a plurality of switches.
A circuit for providing an output signal at an output node proportional to a root-mean-square (RMS) value of an input signal at an input node, wherein the circuit includes circuitry capable of detecting and independently recovering from a fault condition.
Dependencies are inferred from the claim text.