# US 8,786,361 B1 · High accuracy analog interface processing circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,361 B1 - Document ID: US8786361B1 - Status: Granted - Kind: B1 - Application number: 13/789,813 - Filed: 2013-03-08 - Granted: 2014-07-22 - Earliest claimed: 2013-03-08 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Gary L. Hess - Web page: https://patentgrep.com/patent/US8786361B1 ## CPC - H03K 17/145: {in field-effect transistor switches} - G01D 3/028: mitigating undesired influences, e.g. temperature, pressure - 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) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract An analog interface processing circuit includes a first and second signal processing interface, a processing system connected to the first and second signal processing interfaces, a biasing voltage source switchably coupled to said first signal processing interface via a first switch assembly and switchably coupled to said second signal processing interface via a second switch assembly, and a first control output of said processing system controllably coupled to said first switch assembly and a second control output of said processing system controllably couple to said second switch assembly. ## Claims ### Claim 1 An sensor processing circuit comprising: a first and second signal processing interface; a processing system connected to an output of each of said first and second signal processing interfaces; a biasing voltage source switchably coupled to said first signal processing interface via a first switch assembly and switchably coupled to said second signal processing interface via a second switch assembly; and a first control output of said processing system controllably coupled to said first switch assembly and a second control output of said processing system controllably couple to said second switch assembly; wherein said processing system includes a memory storing instructions operable to cause said sensor processing circuit to perform the steps of: connecting a first of said first and second signal processing interfaces to the biasing voltage source, thereby causing said first signal processing interface to pass a sensor signal to the processing system; disconnecting said first of said first and second processing interfaces from said biasing voltage source and connecting a second of said signal processing interfaces to said biasing voltage source while said sensor system is operating at a high temperature; disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature; and alternating the steps of disconnecting said first of said first and second processing interfaces from said biasing voltage source and connecting a second of said signal processing interfaces to said biasing voltage source while said sensor system is operating at a high temperature and disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, at a set time period, wherein said set time period is substantially less than a time period required for ionic contamination to place said sensor signals out of tolerance. ### Claim 2 (depends on 1) The sensor processing circuit of claim 1, wherein said processing system is connected to said outputs of each of said first and second signal processing interfaces via at least one analog to digital converter. ### Claim 3 (depends on 1) The sensor processing circuit of claim 1, wherein each of said first and second signal processing interfaces are connected to an analog sensor. ### Claim 4 (depends on 3) The sensor processing circuit of claim 3, wherein each of said first and second signal processing interfaces is connected to a single analog sensor. ### Claim 5 (depends on 3) The sensor processing circuit of claim 3, wherein each of said first and second signal processing interfaces is connected to distinct analog sensors, and wherein each of the distinct analog sensors are redundant with each other. ### Claim 6 (depends on 1) The sensor processing circuit of claim 1, wherein each of said first and second signal processing interface includes a PN junction interface. ### Claim 7 A method for processing sensor inputs of a sensor system comprising the steps of: receiving a sensor signal at least two signal processing interfaces; connecting a first of said at least two signal processing interfaces to a biasing voltage source, thereby causing said first signal processing interface to pass a sensor signal to a signal processor; disconnecting said first of said at least two signal processing interfaces from said biasing voltage and connecting a second of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, thereby counteracting an ionic contamination of said first of said at least two signal processing interfaces; and alternating the steps of disconnecting said first of said first and second processing interfaces from said biasing voltage source and connecting a second of said signal processing interfaces to said biasing voltage source while said sensor system is operating at a high temperature and disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, at a set time period, wherein said set time period is substantially less than a time period required for ionic contamination to place said sensor signals out of tolerance. ### Claim 8 (depends on 7) The method of claim 7, further comprising the step of disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, thereby counteracting an ionic contamination of said second of said at least two signal processing interfaces. ### Claim 9 (depends on 8) The method of claim 8, wherein said steps of disconnecting said first of said at least two signal processing interfaces from said biasing voltage and connecting a second of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, thereby counteracting an ionic contamination of said first of said at least two signal processing interfaces and disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, thereby counteracting an ionic contamination of said second of said at least two signal processing interfaces are alternated at a set time period. ### Claim 10 (depends on 9) The method of claim 9, wherein said set time period is substantially less than a time period required for ionic contamination to place said sensor signals out of tolerance. ### Claim 11 (depends on 10) The method of claim 10, wherein said set time period is less than or equal to five minutes. ### Claim 12 (depends on 7) The method of claim 7, wherein said step of disconnecting said first of said at least two signal processing interfaces from said biasing voltage and connecting a second of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, thereby counteracting an ionic contamination of said first of said at least two signal processing interfaces is performed when an ionic contamination of said first signal processing interface exceeds a threshold. ### Claim 13 (depends on 12) The method of claim 12, further comprising the step of disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature when an ionic contamination of the second signal processing interface exceeds a threshold, thereby counteracting an ionic contamination of said second of said at least two signal processing interfaces. ### Claim 14 An aircraft sensor configuration comprising: at least one analog sensor; a first and second signal processing interface; a processing system connected to an output of each of said first and second signal processing interfaces; a biasing voltage source switchably coupled to said first signal processing interface via a first switch assembly and switchably coupled to said second signal processing interface via a second switch assembly; and a first control output of said processing system controllably coupled to said first switch assembly and a second control output of said processing system controllably couple to said second switch assembly; wherein said processing system includes a memory storing instructions operable to cause said sensor processing circuit to perform the steps of: connecting a first of said first and second signal processing interfaces to the biasing voltage source, thereby causing said first signal processing interface to pass a sensor signal to the processing system; disconnecting said first of said first and second processing interfaces from said biasing voltage source and connecting a second of said signal processing interfaces to said biasing voltage source while said sensor system is operating at a high temperature; disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature; and alternating the steps of disconnecting said first of said first and second processing interfaces from said biasing voltage source and connecting a second of said signal processing interfaces to said biasing voltage source while said sensor system is operating at a high temperature and disconnecting said second of said at least two signal processing interfaces from said biasing voltage and connecting a first of said signal processing interfaces to said biasing voltage while said sensor system is operating at a high temperature, at a set time period, wherein said set time period is substantially less than a time period required for ionic contamination to place said sensor signals out of tolerance. ### Claim 15 (depends on 14) The aircraft sensor configuration of claim 14, wherein said processing system is connected to said outputs of each of said first and second signal processing interfaces via at least one analog to digital converter. ### Claim 16 (depends on 14) The aircraft sensor configuration of claim 14, wherein each of said first and second signal processing interfaces are connected to an analog sensor. ### Claim 17 (depends on 16) The aircraft sensor configuration of claim 16, wherein each of said first and second signal processing interfaces is connected to a single analog sensor. ### Claim 18 (depends on 16) The aircraft sensor configuration of claim 16, wherein each of said first and second signal processing interfaces is connected to distinct analog sensors, and wherein each of the distinct analog sensors are redundant with each other. ### Claim 19 (depends on 14) The aircraft sensor configuration of claim 14, wherein each of said first and second signal processing interface includes a PN junction interface.