# US 2022/0276646 A1 · Device and method for pre-bootup fault control of a driver output > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0276646 A1 - Document ID: US20220276646A1 - Status: Published application - Kind: A1 - Application number: 17/188,908 - Filed: 2021-03-01 - Published: 2022-09-01 - Earliest claimed: 2021-03-01 - Assignees: Renesas Electronics America Inc. - Applicants: Renesas Electronics America Inc. - Inventors: Lokesh KUMATH; Muthukumaran CHANDRASEKARAN; Berry CONCKLIN; Bin LIU; Ha Chu VU; Matthew COLE - Web page: https://patentgrep.com/patent/US20220276646A1 ## CPC - G05B 19/0425: {Safety, monitoring} - G05B 23/0235: {based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold} - H01S 5/06825: {Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation} - G05B 1/01: electric - G05B 6/00: Internal feedback arrangements for obtaining particular characteristics, e.g. proportional, integral or differential - G05B 23/00: Testing or monitoring of control systems or parts thereof (monitoring of program-control systems G05B19/048, G05B19/406) - G05B 2219/14: Plc safety - G05B 2219/24: Pc safety - G06F 11/00: Error detection; Error correction; Monitoring (error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00) - G06F 11/0736: {in functional embedded systems, i.e. in a data processing system designed as a combination of hardware and software dedicated to performing a certain function (testing or monitoring of automated control systems G05B23/02)} - G06F 11/0796: {Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element} - H01S 5/042: Electrical excitation {; Circuits therefor (monolithically integrated laser drive components H01S5/0261)} - H01S 5/062: by varying the potential of the electrodes (H01S5/065 takes precedence) - H01S 5/06808: {by monitoring the electrical laser parameters, e.g. voltage or current} - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Example implementations include a method of pre-bootup fault monitor of a LASER diode driver output, by applying a first power to a pre-bootup fault monitor device, setting a fault condition at the pre-bootup fault monitor device to a no-fault state, initiating the pre-bootup fault monitor device, determining whether a first impedance of driver output satisfies an impedance threshold, and in response to a determination that the first impedance satisfies the impedance threshold, applying a second power to the output device. Example implementations also include a system with a LASER output device, and a pre-bootup fault monitor device operatively coupled to the LASER output device, and operable to activate in response to receiving a first power, set a fault condition to a no-fault state, determine whether a first impedance of the output driver satisfies an impedance threshold, and, in response to a determination that the first impedance satisfies the impedance threshold, apply a second power to the LASER output device, and a power-on reset controller operatively coupled to the pre-bootup fault monitor and operable to, in response to the determination that the first impedance satisfies the impedance threshold, deactivate the pre-bootup fault monitor. ## Claims ### Claim 1 A method of pre-bootup fault control of LASER diode driver output, the method comprising: applying a first power to a pre-bootup fault monitor device; setting a fault condition at the pre-bootup fault monitor device to a no-fault state; initiating the pre-bootup fault monitor device; determining whether a first impedance of an output driver, at an output driver node, satisfies an impedance threshold; and in response to a determination that the first impedance satisfies the impedance threshold, blocking application of a second power to the output driver node, the output driver node coupled with an output device. ### Claim 2 (depends on 1) The method of claim 1, further comprising: detecting the first impedance at an output node operatively coupled to the output device. ### Claim 3 (depends on 1) The method of claim 1, wherein the impedance threshold comprises a second impedance. ### Claim 4 (depends on 3) The method of claim 3, further comprising: detecting the second impedance at the pre-bootup fault monitor device. ### Claim 5 (depends on 1) The method of claim 1, wherein the determining whether the first impedance satisfies the impedance threshold comprises determining whether the first impedance is greater than the impedance threshold. ### Claim 6 (depends on 1) The method of claim 1, wherein the determining whether the first impedance satisfies the impedance threshold comprises determining whether the first impedance is greater than the impedance threshold. ### Claim 7 (depends on 1) The method of claim 1, further comprising: in response to the determination that the first impedance satisfies the impedance threshold, deactivating the pre-bootup fault monitor. ### Claim 8 (depends on 7) The method of claim 7, wherein the deactivating the pre-bootup fault monitor further comprises deactivating the pre-bootup fault monitor by a power-on reset controller. ### Claim 9 (depends on 1) The method of claim 1, further comprising: in response the determination that the first impedance satisfies the impedance threshold, activating an active mode fault monitor. ### Claim 10 (depends on 1) The method of claim 1, wherein the determination that the first impedance satisfies the impedance threshold further comprises a determination that the first impedance satisfies the impedance threshold after a predetermined delay. ### Claim 11 (depends on 1) The method of claim 1, further comprising: in response to a determination that the first impedance does not satisfy the impedance threshold, setting the fault condition to a fault state. ### Claim 12 A device comprising: a pre-bootup fault monitor device operatively coupled with a laser output device, and operable to activate in response to receiving a first power, set a fault condition to a no-fault state, determine whether a first impedance of a laser output device, at an output driver node, satisfies an impedance threshold, and, in response to a determination that the first impedance satisfies the impedance threshold, block application of a second power to the output driver node, the output driver node coupled with the laser output device. ### Claim 13 (depends on 12) The device of claim 12, wherein the pre-bootup fault monitor device is further operable to detect the first impedance to ground at an output node operatively coupled to the output device. ### Claim 14 (depends on 12) The device of claim 12, wherein the impedance threshold comprises a second impedance. ### Claim 15 (depends on 14) The device of claim 14, wherein the pre-bootup fault monitor device is further operable to detect the second impedance by an internal reference impedance to ground. ### Claim 16 (depends on 12) The device of claim 12, further comprising: a system processor operatively coupled to the pre-bootup fault monitor and operable to, in response to the determination that the first impedance satisfies the impedance threshold, deactivate the pre-bootup fault monitor. ### Claim 17 (depends on 16) The method of claim 16, wherein the system processor is further operable to, in response the determination that the first impedance satisfies the impedance threshold, activate an active mode fault monitor. ### Claim 18 (depends on 12) The device of claim 12, further comprising: a power-on reset controller operatively coupled with a system processor and the pre-bootup fault monitor, and operable to deactivate the pre-bootup fault monitor. ### Claim 19 (depends on 12) The method of claim 12, wherein the power-on reset controller is further operable to determine that the first impedance satisfies the impedance threshold after a predetermined delay. ### Claim 20 A system comprising: a laser output device; a pre-bootup fault monitor device operatively coupled with the laser output device, and operable to activate in response to receiving a first power, set a fault condition to a no-fault state, determine whether a first impedance of an output driver, at an output driver node, satisfies an impedance threshold, and, in response to a determination that the first impedance satisfies the impedance threshold, block application of a second power to the output driver node, the output driver node coupled with the laser output device; and a power-on reset controller operatively coupled to the pre-bootup fault monitor and operable to, in response to the determination that the first impedance satisfies the impedance threshold, deactivate the pre-bootup fault monitor.