# US 2022/0286154 A1 · Measurement circuit for isolation product > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0286154 A1 - Document ID: US20220286154A1 - Status: Published application - Kind: A1 - Application number: 17/826,469 - Filed: 2022-05-27 - Published: 2022-09-08 - Earliest claimed: 2020-09-30 - Assignees: Skyworks Solutions, Inc. - Applicants: Skyworks Solutions, Inc. - Inventors: Carlos J. Briseno-Vidrios - Web page: https://patentgrep.com/patent/US20220286154A1 ## CPC - H04B 1/1027: {assessing signal quality or detecting noise/interference for the received signal} - H03F 3/45188: {Non-folded cascode stages} - H03F 3/45475: {using IC blocks as the active amplifying circuit} - H03G 1/0029: {using field-effect transistors [FET]} - H03G 3/3089: {Control of digital or coded signals} - H03K 19/017509: {Interface arrangements} - H04B 1/123: {using adaptive balancing or compensation means (adaptive filter circuits and algorithms H03H)} - H04B 1/1615: {Switching on; Switching off, e.g. remotely (battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34)} - H03F 2200/405: the output amplifying stage of an amplifier comprising more than three power stages - H03G 2201/103: being an amplifying element - H04B: TRANSMISSION - H03F: AMPLIFIERS - H03G: CONTROL OF AMPLIFICATION - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A method for measuring a received signal includes receiving a differential pair of signals by a differential pair of input nodes of a differential circuit. The method includes attempting to match a first current through a first node of the differential circuit corresponding to the differential pair of signals to a second current through a second node of the differential circuit corresponding to a feedback signal. The method includes generating an output measurement signal based on the first current and the second current. The output measurement signal has a level corresponding to an average amplitude of the differential pair of signals. ## Claims ### Claim 1 A method for measuring a received signal, the method comprising: receiving a differential pair of signals by a differential pair of input nodes of a differential circuit; attempting to match a first current through a first node of the differential circuit corresponding to the differential pair of signals to a second current through a second node of the differential circuit corresponding to a feedback signal; and generating an output measurement signal based on the first current and the second current, the output measurement signal having a level corresponding to an average amplitude of the differential pair of signals. ### Claim 2 (depends on 1) The method as recited in claim 1 wherein the output measurement signal has a linear relationship to a root mean square proportional function of a full-wave rectified version of the differential pair of signals. ### Claim 3 (depends on 2) The method as recited in claim 2 wherein a gain of the linear relationship is determined based on attenuation in a feedback circuit used to generate the feedback signal based on the output measurement signal. ### Claim 4 (depends on 1) The method as recited in claim 1 wherein generating the first current comprises detecting a lesser signal of a first signal of the differential pair of signals and a second signal of the differential pair of signals, enabling a corresponding branch of the differential circuit as active, and disabling a second branch of the differential circuit associated with the other signal of the first signal and the second signal. ### Claim 5 (depends on 1) The method as recited in claim 1 wherein generating the output measurement signal comprises performing a differential to single-ended conversion based on the first current and the second current to generate the output measurement signal. ### Claim 6 (depends on 1) The method as recited in claim 1 wherein the output measurement signal is a full-wave rectified version of the differential pair of signals. ### Claim 7 (depends on 1) The method as recited in claim 1 further comprising performing an analog-to-digital conversion of the output measurement signal to a multi-bit digital output measurement signal wherein a first resolution of the multi-bit digital output measurement signal is limited only by a second resolution of an analog-to-digital conversion. ### Claim 8 (depends on 7) The method as recited in claim 7 further comprising calibrating an isolator product in a diagnostic mode of operation in response to the multi-bit digital output measurement signal being non-zero. ### Claim 9 (depends on 1) The method as recited in claim 1 further comprising converting the output measurement signal to a one-bit digital signal based on a comparison of the output measurement signal to a predetermined threshold voltage in a first mode of operation. ### Claim 10 (depends on 1) The method as recited in claim 1 wherein generating the first current and the second current rectifies the differential pair of signals and removes a carrier signal from the differential pair of signals. ### Claim 11 A receiver comprising: a differential pair of nodes; and a differential circuit configured to attempt to match a first current through a first node based on a received signal provided to the differential pair of nodes and configured to generate a second current through a second node, the second current being based on a feedback signal; and a cascode circuit configured to provide an output measurement signal based on the first current and the second current, the output measurement signal having a level corresponding to an average amplitude of the received signal. ### Claim 12 (depends on 11) The receiver as recited in claim 11 wherein the output measurement signal has a linear relationship to a root mean square proportional function of a full-wave rectified version of the received signal. ### Claim 13 (depends on 12) The receiver as recited in claim 12 wherein a gain of the linear relationship is determined based a resistance in a feedback circuit coupled between the cascode circuit and the differential circuit. ### Claim 14 (depends on 11) The receiver as recited in claim 11 wherein the receiver is selectively configured to provide the output measurement signal as an output in response to the receiver being configured in a diagnostic mode of operation. ### Claim 15 (depends on 11) The receiver as recited in claim 11 wherein the differential circuit comprises: a first branch coupled to a first input node of the differential pair of nodes and a first output node; a second branch coupled to a second input node of the differential pair of nodes and the first output node; and a third branch coupled between a feedback circuit and a second output node. ### Claim 16 (depends on 15) The receiver as recited in claim 15 wherein the third branch has a strength equal to a combination of the strengths of the first branch and the second branch and is configured to match the first current to the second current. ### Claim 17 (depends on 11) The receiver as recited in claim 11 further comprising an analog-to-digital converter circuit configured to convert the output measurement signal to a multi-bit digital output measurement signal in a diagnostic mode of operation, a first resolution of the multi-bit digital output measurement signal being limited only by a second resolution of an analog-to-digital conversion. ### Claim 18 (depends on 11) The receiver as recited in claim 11 further comprising a comparator configured to convert the output measurement signal to a one-bit digital signal based on a comparison of the output measurement signal to a predetermined threshold voltage in a normal mode of operation. ### Claim 19 An isolator product comprising: a transmitter in a first integrated circuit die, the transmitter being selectively configured to transmit a common mode test signal having a frequency of a carrier signal used to transmit data via an isolation channel in a normal mode of operation of the isolator product; a differential pair of nodes in a receiver in a second integrated circuit die, the differential pair of nodes being configured to generate a received signal in response to the receiver receiving the common mode test signal from the second integrated circuit die via the isolation channel; the isolation channel coupled between the transmitter in the first integrated circuit die and the receiver in the second integrated circuit die; a differential circuit configured to attempt to match a first current through a first node based on the received signal provided to the differential pair of nodes and configured to generate a second current through a second node, the second current being based on a feedback signal; and a cascode circuit configured to provide an output measurement signal based on the first current and the second current, the output measurement signal having a level corresponding to an average amplitude of the received signal. ### Claim 20 (depends on 19) The isolator product as recited in claim 19 wherein the output measurement signal has a linear relationship to a root mean square proportional function of a full-wave rectified version of the received signal.