# US 2019/0173514 A1 · Signal isolator having magnetic signal latching > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173514 A1 - Document ID: US20190173514A1 - Status: Published application - Kind: A1 - Application number: 16/256,215 - Filed: 2019-01-24 - Published: 2019-06-06 - Earliest claimed: 2017-11-02 - Assignees: Allegro MicroSystems, LLC - Applicants: Allegro MicroSystems, LLC - Inventors: Robert A. Briano - Web page: https://patentgrep.com/patent/US20190173514A1 ## CPC - H04B 1/44: Transmit/receive switching - G01R 33/09: Magnetoresistive devices - H04B 17/17: Detection of non-compliance or faulty performance, e.g. response deviations (H04B17/18 takes precedence) - H04L 25/0266: {Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling} - H04L 25/085: {Arrangements for reducing interference in line transmission systems, e.g. by differential transmission} - H04B: TRANSMISSION - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Methods and apparatus for transmitting signals that are magnetically latched at a receiver. In embodiments, a signal isolator comprises a transmitter and a receiver on separate die. Signal disruptions may be minimized. In embodiments, the transmitter and/or receiver can be monitored for proper operation. ## Claims ### Claim 1 A signal isolator, comprising: a transmitter comprising: a transmit module to receive an input signal; and a transmit current latching module to magnetically latch an output of the transmit module; and a receiver comprising: a receive module including a receiver magnetic field sensing element to detect and magnetically latch a signal from the transmit current latching module. ### Claim 2 (depends on 1) The signal isolator according to claim 1, wherein the transmit module further includes a transmitter receive module to receive signals from the receiver. ### Claim 3 (depends on 2) The signal isolator according to claim 2, wherein the receiver further includes: a receiver echo module coupled to the receiver magnetic field sensing element; and a receive current latching module to receive an output of the receiver echo module and transmit an output to the transmitter receive module. ### Claim 4 (depends on 1) The signal isolator according to claim 1, further comprising a barrier region between the transmitter and the receiver. ### Claim 5 (depends on 1) The signal isolator according to claim 1, wherein the transmitter and the receiver are disposed on separate die. ### Claim 6 (depends on 1) The signal isolator according to claim 1, wherein the receiver magnetic field sensing element includes a magnetoresistive element. ### Claim 7 (depends on 6) The signal isolator according to claim 6, wherein the magnetoresistive element comprises a bi-stable magnetoresistive element. ### Claim 8 (depends on 1) The signal isolator according to claim 1, wherein the transmit module includes a controller. ### Claim 9 (depends on 8) The signal isolator according to claim 8, wherein the controller monitors a state of the input signal, the transmit current latching module, and a transmitter receive module. ### Claim 10 (depends on 9) The signal isolator according to claim 9, wherein the controller is configured to resend a signal from the transmitter to the receiver when a disruption of the input signal is detected. ### Claim 11 (depends on 10) The signal isolator according to claim 10, wherein the disruption is detected when a timeout is exceeded. ### Claim 12 (depends on 1) The signal isolator according to claim 1, further including a watchdog timer coupled to a receive echo module to detect faults in the receiver module and/or transmit module when data signals are not present. ### Claim 13 A method of communicating signals from a transmitter to a receiver isolated from the transmitter, comprising: employing a transmitter having a transmit module to receive an input signal and a transmit current latching module to magnetically latch an output of the transmit module; and employing a receiver having a receive module including a receiver magnetic field sensing element to detect and magnetically latch a signal from the transmit current latching module. ### Claim 14 (depends on 13) The method to claim 13, wherein the transmit module further includes a transmitter receive module to receive signals from the receiver. ### Claim 15 (depends on 14) The method according to claim 14, wherein the receiver further includes: a receiver echo module coupled to the receiver magnetic field sensing element; and a receive current latching module to receive an output of the receiver echo module and transmit an output to the transmitter receive module. ### Claim 16 (depends on 13) The method according to claim 13, further employing a barrier region between the transmitter and the receiver. ### Claim 17 (depends on 13) The method according to claim 13, wherein the transmitter and the receiver are disposed on separate die. ### Claim 18 (depends on 13) The method according to claim 13, wherein the receiver magnetic field sensing element includes a magnetoresistive element. ### Claim 19 (depends on 18) The method according to claim 18, wherein the magnetoresistive element comprises a bi-stable magnetoresistive element. ### Claim 20 (depends on 13) The method according to claim 13, further including employing a controller to monitor a state of the input signal, the transmit current latching module, and a transmitter receive module. ### Claim 21 (depends on 20) The method according to claim 20, wherein the controller is configured to resend a signal from the transmitter to the receiver when a disruption of the input signal is detected. ### Claim 22 (depends on 21) The method according to claim 21, wherein the disruption is detected when a timeout is exceeded. ### Claim 23 (depends on 13) The method according to claim 13, further including employing a watchdog timer coupled to a receive echo module to detect faults in the receiver module and/or transmit module when data signals are not present. ### Claim 24 A signal isolator, comprising: a transmitter comprising: a transmit means to receive an input signal; a transmit current latching means to magnetically latch an output of the transmit means; and a receiver comprising: a receive means including a receiver magnetic field sensing means for detecting and magnetically latching a signal from the transmit latching means. ### Claim 25 (depends on 24) The signal isolator according to claim 24, wherein the transmit means further includes a transmitter receive means for receiving signals from the receiver. ### Claim 26 (depends on 24) The signal isolator according to claim 24, wherein the receiver further includes: a receiver echo means coupled to the receiver magnetic field sensing means; and a receive current latching means for receiving an output of the receiver echo means and transmitting an output to the transmitter receive means.