Galvanic isolation integrated in a signal channel
First Claim
1. A system for transferring signals between an electrical circuit with a first common reference and an electrical circuit with a second common reference, the system comprising:
- a capacitively coupled signal line coupled between the first and second referenced electrical circuits to permit transfer of signals and high-voltage isolation between the first and second referenced electrical circuits;
a transmitter or receiver in the first referenced electrical circuit and coupled to the signal line to send or receive a signal, respectively;
a receiver or transmitter in the second referenced electrical circuit and coupled to the signal line to receive or send a signal, respectively, in conjunction with the transmitter or receiver of the first referenced electrical circuit; and
an impedance coupled to the signal line and operable to be configured to compensate capacitive values in the capacitively coupled signal line.
1 Assignment
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Accused Products
Abstract
A communication link between two isolated electrical devices provides for adjustable impedances coupled to the communication link signal paths to balance the signal paths and improve CMRR. The communication link may be a bidirectional capacitively coupled differential signal line to improve noise rejection. The capacitance may be realized as portions of circuit board traces, lead frames, IC pins and/or molding on ICs or on an IC package. The variable impedance compensates for variances in the capacitive coupling values so that the signal paths react similarly in the presence of noise or interference. The variable impedance may be set or programmed from stored values that may be digital or analog. The capacitive coupling of the differential signal line permits integration of isolated devices in a common package.
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Citations
23 Claims
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1. A system for transferring signals between an electrical circuit with a first common reference and an electrical circuit with a second common reference, the system comprising:
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a capacitively coupled signal line coupled between the first and second referenced electrical circuits to permit transfer of signals and high-voltage isolation between the first and second referenced electrical circuits; a transmitter or receiver in the first referenced electrical circuit and coupled to the signal line to send or receive a signal, respectively; a receiver or transmitter in the second referenced electrical circuit and coupled to the signal line to receive or send a signal, respectively, in conjunction with the transmitter or receiver of the first referenced electrical circuit; and an impedance coupled to the signal line and operable to be configured to compensate capacitive values in the capacitively coupled signal line. - View Dependent Claims (2, 3, 4, 5, 22)
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6. A bi-directional communication link between electrically isolated devices, comprising:
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bi-directional transceivers coupled to each end of the communication link; a capacitive value associated with each signal path in the bi-directional communication link; one or more compensation impedances coupled to one or more signal paths of the bi-directional communication link; and the one or more compensation impedances having a value to compensate for mismatches in the capacitive values to obtain balanced signal paths in the bi-directional communication link. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 23)
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16. A method for communicating a signal across a high-voltage isolation barrier, comprising:
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providing a capacitively coupled communication link between the two electrically isolated devices; compensating one or more capacitive values in the capacitively coupled communication link; tuning the compensation to optimize CMRR. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification