Capacitive data transmission over a galvanic isolation
AssigneeInfineon Technologies AG
InventorMarcus Nuebling
Life of this patent
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Abstract
In some examples, a device includes a capacitor arranged across the galvanic isolation barrier, where the capacitor is configured to communicate a single-ended signal from a first voltage domain to a second voltage domain. The device also includes a high-pass filter arranged in the second voltage domain and configured to receive the single-ended signal from the capacitor. The device further includes a low-pass filter arranged in the second voltage domain and coupled between the high-pass filter and a low-impedance node. The high-pass filter is coupled between the capacitor, the low-pass filter, and the low-impedance node, and the low-pass filter is configured to generate a differential signal.
Claims20
A device arranged to include a galvanic isolation barrier between a first voltage domain and a second voltage domain, the device comprising:
- a capacitor arranged across the galvanic isolation barrier, wherein the capacitor is configured to communicate a single-ended signal from the first voltage domain to the second voltage domain;
- a high-pass filter arranged in the second voltage domain and configured to receive the single-ended signal from the capacitor;
- a low-pass filter arranged in the second voltage domain and coupled between the high-pass filter and a low-impedance node, wherein output of the high-pass filter comprises a first signal that defines input to the low pass filter;
- and
- a differential gain stage,
- wherein the high-pass filter is coupled between the capacitor, the low-pass filter, and the low-impedance node,
- wherein the low-pass filter is configured to filter the first signal to generate a second signal, and
- wherein the differential gain stage is configured to:
- receive the first signal from the high-pass filter and the second signal from the low-pass filter;
- and
- output a third signal based on the first signal and the second signal.
A method comprising:
- receiving a single-ended signal from a capacitor arranged across a galvanic isolation barrier, wherein the galvanic isolation barrier separates a first voltage domain from a second voltage domain;
- filtering the single-ended signal through a high-pass filter arranged in the second voltage domain between the capacitor and a low-impedance node to generate a first signal that comprises a high-pass-filtered signal;
- filtering the first signal through a low-pass filter arranged in the second voltage domain between the high-pass filter and the low-impedance node to generate a second signal;
- receiving the first signal from the high-pass filter and the second signal from the low-pass filter at a differential gain stage;
- and
- outputting a third signal from the differential gain stage based on the first signal and the second signal.
A system arranged to include a galvanic isolation barrier between a first voltage domain and a second voltage domain comprising:
- an oscillator configured to generate a single-ended signal at a transmission frequency, wherein the oscillator is arranged in the first voltage domain;
- a capacitor arranged across the galvanic isolation barrier, wherein the capacitor is configured to communicate the single-ended signal from the first voltage domain to the second voltage domain;
- a high-pass filter arranged in the second voltage domain and coupled between the capacitor and a low-impedance node;
- a low-pass filter arranged in the second voltage domain and coupled between the high-pass filter and the low-impedance node, wherein output of the high-pass filter comprises a first signal that defines input to the low pass filter and wherein the low pass filter is configured to filter the first signal to generate a second signal;
- a differential gain stage, wherein the differential gain stage is configured to:
- receive the first signal from the high-pass filter and the second signal from the low-pass filter, and
- output a third signal based on the first signal and the second signal;
- and
- a downstream filter circuit arranged in the second voltage domain and configured to filter the third signal,
- wherein the transmission frequency is higher than a corner frequency of the high-pass filter,
- wherein the low-pass filter is coupled between the downstream filter circuit, the high-pass filter, and the low-impedance node,
- wherein the corner frequency of the high-pass filter is higher than a corner frequency of the low-pass filter, and
- wherein the corner frequency of the low-pass filter is higher than a corner frequency of the downstream filter circuit.
Dependencies are inferred from the claim text.