TWI621839B - Active optical cable and method of calculating ah effective age of the same - Google Patents

Abstract

The present invention provides a method of calculating an effective age of an active optical cable, the active optical cable comprising a fiber optic cable, at least one optical transducer, a first memory, and a second memory, the method comprising: Sensing an operational parameter of the active optical cable and recording a correspondence in the second memory during a regular time interval divided into a plurality of regular sub-time intervals and after each of the regular sub-time intervals a value of the sensed operational parameter; after each of the regular time intervals, the value recorded in the second memory is stored in the first memory; and is stored The effective age of the active optical cable is calculated based on the values in the first memory.

Description

Active optical cable and method for calculating its effective age

The invention relates to a method of measuring and recording temperature data of an active component and is related to a method of estimating the remaining lifetime of the active component. More specifically, the present invention relates to a method of measuring and recording temperature data of an active device using a memory having limited write capability and limited capacity, and estimating its remaining based on temperature history data of the active component. The method of life is related.

The lifetime (that is, the time before the failure occurs) depends on the operating environment of the active component, which includes temperature, humidity, ..., and the like. Mean Time To Failure (MTTF) is the average estimated operating time of components before failure occurs. The MTTF of an active component is also dependent on the operating environment of the active component. Manufacturers typically provide MTTF in a given operating condition (temperature, humidity, current, ..., etc.). However, the operating temperature of the active components can vary greatly with the application.

An example of an active component is a Vertical Cavity Surface-Emitting Laser (VCSEL). VCSELs are semiconductor light sources that emit the same dimming and are typically integrated into the system in fiber optic applications. One such system is an Active Optical Cable (AOC), which is a fiber optic cable, which is called a transducer. (transducer) electrical to optical converter and / or optical to electrical converter. VCSELs tend to wear more quickly at high temperatures and are the most likely source of failure among AOCs. A VCSEL can represent a single laser or a laser array in a single die (ie, a VCSEL array).

The problem with active components is that they don't know when they will fail. Ideally, the conditions of the operating environment of the active components are continuously monitored and recorded. However, this may not be the case. For example, AOC cannot continuously monitor and record temperature because AOC's non-volatile memory can only be written a limited number of times. If an Electrically Erasable Programmable Read-Only Memory (EEPROM) semiconductor component is used as the memory of the AOC, the memory will have a limited number of write cycles. In one example, a particular EEPROM fabricated by ATMEL (San Jose, Calif.) will have a nominal 30,000 write cycles prior to failure at an operating temperature of 85 °C.

In order to overcome the above problems, a preferred embodiment of the present invention provides a method for measuring and recording temperature data of an active device using a memory having limited write capability and limited capacity, and providing an estimate using the temperature data. A method of estimating the age of the active component.

In an embodiment of the invention, an AOC is provided that includes a VCSEL, a volatile memory component and a non-volatile memory component, a processor, and a sensor. The sensor provides information related to operational parameters that affect the aging of the active components. The sensor is monitored by the processor during regular sub-time intervals and the generated information is stored in volatile memory. The information stored in the volatile memory is transmitted by the processor and written to the non-volatile memory at regular time intervals, the length of a time interval Greater than the length of a sub-period of time to reduce the number of write cycles of the non-volatile memory. The information stored in the non-volatile memory is used to determine the effective age of the active component.

A preferred embodiment of the present invention provides an active optical cable comprising: a fiber optic cable; at least one optical transducer; a first memory; a second memory; a sensor, which senses Measure the operational parameters of the active optical cable; and a processor coupled to the at least one optical transducer, the first memory, the second memory, and the sensor. During a regular time interval divided into a plurality of regular sub-time intervals and after each of the regular sub-time intervals, the processor records a corresponding one in the second memory corresponding to a sensed The values of the operational parameters are stored, and the values recorded in the second memory are stored in the first memory after each of the regular time intervals.

The regular time intervals and the regular sub-time intervals are preferably based on the expected number of writes of the first memory and the expected lifetime of the active optical cable. This operating parameter is preferably a temperature.

Preferably, the second memory comprises a plurality of bins, and each of the packets corresponds to a range of values of the sensed operating parameter. Preferably, the processor is configured to increment the grouping value of the packet corresponding to the value range of the sensed operating parameter (which includes the value of the sensed operating parameter) by one. The value corresponding to the sensed operational parameter is recorded. Preferably, the first memory comprises a plurality of packets corresponding to the packets in the second memory. Preferably, the processor is to be recorded by adding a packet value of each of the second memories to a corresponding packet value among the corresponding packets previously stored in the first memory. The value in the second memory is stored in the first memory. The processor preferably calculates the effective age of the active optical cable based on the packet values of the packets stored in the first memory. Preferably, the processor calculates the effective age based only on the grouping values of the packets stored in the first memory. Preferably, the processor provides an indicator signal if the effective age is above a threshold. The preferred system, the operating parameter is temperature; each of the plurality of packet by key represents a temperature range; and the processor may be calculated using the following equation _t effective Effective Age of the active optical cable: among them, m is the time in the regular sub-time interval in minutes, b is the number of packets, N _n is the value stored in packet n, E _A is the activation energy, and k _B is Bozeman Boltzman's constant, T _n is the grouping temperature, and T _R is the reference temperature.

Preferably, after each of the regular time intervals, the processor resets the value stored in the second memory. Preferably, the processor calculates the effective age of the active optical cable based on the value stored in the first memory. Preferably, the first memory is a non-volatile memory, and the second memory is preferably a volatile memory. The first memory is preferably an EEPROM.

A preferred embodiment of the present invention provides a method of calculating an effective age of an active optical cable, the active optical cable including a fiber optic cable, at least one optical transducer, a first memory, and a second memory Body, the method comprising: sensing the regular time interval divided into a plurality of regular sub-time intervals and after each of the regular sub-time intervals An operational parameter of the active optical cable and recording a value corresponding to a sensed operational parameter in the second memory; after each of the regular time intervals, the second memory is recorded The value in the body is stored in the first memory; and the effective age of the active optical cable is calculated based on the value stored in the first memory.

The regular time intervals and the regular sub-time intervals are preferably based on the expected number of writes of the first memory and the expected lifetime of the active optical cable. This operating parameter is preferably a temperature.

Preferably, the second memory comprises a plurality of packets, and each of the packets corresponds to a range of values of the sensed operational parameter. Recording a value corresponding to the sensed operational parameter among the second memories preferably includes a range of values corresponding to the sensed operational parameter (which includes the value of the sensed operational parameter) The packet value of the packet is incremented by one. Preferably, the first memory comprises a plurality of packets corresponding to the packets in the second memory. Storing the value recorded in the second memory in the first memory preferably includes adding a packet value of each of the second memories to the first stored in the first memory. The corresponding packet value among the corresponding packets in the memory. Calculating the effective age of the active optical cable is preferably based on the grouping values of the packets stored in the first memory. The calculation of the effective age is preferably based only on the grouping values of the packets stored in the first memory. Further preferably, the method includes providing an indicator signal if the effective age is above a threshold value. Preferably, the operating parameter is temperature; each of the groups represents a temperature range; and calculating the effective age of the active optical cable comprises utilizing the following equation: among them, , t _effective is the effective age of the active optical cable, m is the time in the regular sub-time interval in minutes, b is the number of packets, N _n is the value stored in the packet n, and E _A is the activation energy , k _B is the Boltzmann constant, T _n is the grouping temperature, and T _R is the reference temperature.

The method further preferably includes resetting the value stored in the second memory after each of the regular time intervals. Preferably, the first memory is a non-volatile memory, and the second memory is preferably a volatile memory. The first memory is preferably an EEPROM.

The above and other features, elements, features, steps and advantages of the present invention will become more apparent from the description of the appended claims.

101‧‧‧shell

102‧‧‧Substrate

103‧‧‧Microprocessor

107‧‧‧Photodetector

108‧‧‧ Optical riser

109‧‧‧Vertical Cavity Surface Emitting Laser (VCSEL)

110‧‧‧Molded Optical Structure (MOS)

111‧‧‧ optical cable

112‧‧‧Fiber

202‧‧‧Substrate

203‧‧‧Microprocessor

209‧‧‧Vertical Cavity Surface Emitting Laser (VCSEL)

210‧‧‧Molded Optical Structure (MOS)

211‧‧‧ optical cable

213‧‧‧ Heat sink

214‧‧‧ drive

1 is a flow chart in accordance with a preferred embodiment of the present invention.

Figure 2 shows an exploded view of an AOC.

The diagram shown in Figure 3 can be used for the printed circuit board of the AOC shown in Figure 2 and an exploded view of the molded optical structure.

Figure 4 is a rear perspective view of the printed circuit board shown in Figure 3.

Figure 5 is a front perspective view of another AOC.

Figure 6 is an exploded view of the AOC shown in Figure 5.

Figure 7 is an exploded view of the printed circuit board and molded optical structure shown in Figure 6.

The present invention contemplates the remaining life of the active component so that it can be replaced in advance before the active component or system incorporating the active component fails. Passive mechanisms and/or methods need to determine the probability of failure based on the operating environment of the active component. Accordingly, a preferred embodiment of the present invention would: 1) store information relating to the operational parameter(s) of the active component at regular time intervals, wherein the operational parameter(s) are more than the time intervals The short regular sub-time interval is monitored and recorded; and 2) the effective age of the active component is determined from the stored information.

A specific example of various preferred embodiments of the present invention provides a method of measuring and recording the temperature of an active device using a memory having limited write capability and limited capacity, and providing an estimate of the active component using the temperature data. Estimated method of effective age and thus estimating the remaining expected lifetime. The remaining expected lifetime can be used to pre-replace the active component or the system containing the active component prior to failure, that is, the AOC.

Storing temperature-time-spent-at-temperature data and using appropriate life-time estimation methods to estimate the age of active components has several benefits. First, the lifetime estimation method can be modified based on the application. Second, when new reliability data is available, the updated lifetime estimates can be calculated. Third, the additional computational power within the board is reduced compared to the in-board computing power required to implement the estimated age calculation by the system processor.

Knowing the approximate rate at which the active component (eg, VCSEL) ages as a function of temperature and knowing the amount of time the active component spends at each temperature can predict the active element The age of the piece, and thus the remaining life of the active component. Active component manufacturers typically provide a relationship between the aging rate and the temperature of the active component, that is, the temperature of the functional active component can be measured by a sensor placed near the active component and recorded at any time. As long as the active component is powered on. The temperature sensor can be used to passively estimate the lifetime of the active component without the need for additional circuitry. A suitable lifetime estimation method can be used to determine the effective age of the active component based on the active component operating at a constant reference temperature (which may be, for example, 40 °C).

Previous methods and apparatus described with respect to operating temperatures can be applied to other factors that affect the life of an active component. The same age predictions that will be applied to other conditions of the component (which include humidity, temperature cycling, operating current, ..., etc.) will need to be able to measure the amount of time spent at each of the stressed conditions. For example, for an active component that ages faster at high currents, the current or power consumption of the active component can be monitored over time to predict device age.

The VCSEL is an active component used in a particular example of a preferred embodiment of the invention; however, the invention can be applied to other active components. For example, AOC typically includes many types of active components, such as, but not limited to, transimpedance amplifiers, photodetectors, laser drivers, light sources other than VCSELs, and the like. The preferred embodiment of the invention can be applied to any of these active components as well. A VCSEL would preferably be used in the preferred embodiment of the invention because the VCSEL is expected to be the first failed component; however, if another active component is expected to be the first to fail, then The best system uses the first failed active component. The age of the VCSEL can be estimated without the need to directly monitor the optical output of the VCSEL (which would require additional components). Instead, the temperature of the VCSEL is passively monitored.

Figure 2 shows an exploded view of an AOC. Figure 2 of the present application is the same as Figure 1 of the application Nos. 12/944,545 and 12/944,562, the entire contents of each of which are incorporated herein by reference. The AOC comprises: a housing 101; an optical cable 111 having an optical fiber 112; a substrate 102; a molded optical structure (MOS) 110 coupled to or coupled to the substrate 102 and coupled or coupled To the optical fiber 112; and an optical riser 108. The substrate 102 includes a photodetector 107, a VCSEL 109, and a microprocessor 103. The diagram shown in FIG. 3 can be used for the substrate 102 of the AOC shown in FIG. 2 and the exploded view of the MOS 110. The back side of the substrate 102 shown in FIG. 3 is shown in FIG. Figure 3 shows the VCSEL 109 located below the MOS 110. 4 shows a microprocessor 103 on the back side of substrate 102, which preferably includes non-volatile memory (ie, EEPROM) and volatile memory. Substrate 102 also includes a temperature sensor that can be used to determine the temperature of VCSEL 109. The temperature sensor can be a stand-alone device or can be integrated into other devices in the printed circuit board or placed elsewhere in the AOC near the VCSEL 109. Preferably, multiple functions are incorporated into a single semiconductor wafer. For example, the microprocessor, sensor, volatile memory, non-volatile memory, and VCSEL driver can be incorporated into a single Application Specific Integrated Circuit (ASIC).

The system shown in Figure 5 can be used in an optical receiver in an AOC. The receiver is identical to the optical transceivers shown in U.S. Application Nos. 13/539,173, 13/758,464, 13/895,571, 13/950,628, and 14/295,367. In one of them, this article incorporates their complete content by reference. For example, the receivers of Figures 5 through 7 of the present application are identical to Figures 15A of U.S. Application Serial No. 13/539,173. The optical transceiver shown in 17B. The receiver comprises: an optical cable 211; a substrate 202; a MOS 210 coupled to or connected to the substrate 202 and coupled to or connected to the optical fiber 212; a microprocessor 203; and an unnecessary heat sink 213. The substrate 202 includes a driver 214, a VCSEL 209, and a microprocessor 203. Figure 6 is an exploded view of the receiver shown in Figure 5. FIG. 7 is an exploded view of the substrate 202 and the MOS 210 shown in FIG. FIG. 7 shows VCSEL 209 and microprocessor 203 located below MOS 210. Like the microprocessor 103 shown in FIG. 4, the microprocessor 203 shown in FIG. 7 preferably includes non-volatile memory (ie, EEPROM) and volatile memory.

Although a EEPROM is used as a memory element in a particular example of a preferred embodiment of the invention; however, the preferred embodiment of the invention may be applied to other suitable types of memory. Any static memory (for example, SRAM) can be used. Volatile memory can also be used in place of non-volatile memory if data can be retained in volatile memory when the active device is turned off.

Temperature grouping

The temperature grouping method according to the preferred embodiment of the present invention can be used for a memory having limited write capability and limited capacity, such as an EEPROM. Because there is usually not enough room in the EEPROM to record accurate temperature readings, the temperature values must be "grouped", where each packet represents a different temperature range. This temperature grouping method is used to create a temperature histogram that can be used to predict the age of the active components. Next, a suitable lifetime estimation algorithm is applied to the temperature histogram to determine the effective age of the active component, which can estimate the remaining lifetime of the active component.

The temperature histogram will be divided into multiple temperature groups, each of which represents A different temperature range. For example, each temperature group can represent a temperature range of 5 °C. The fullness of each temperature group provides an indication of the amount of time spent at that temperature range. For example, if the degree of fullness of the temperature group of 25 ° C to 30 ° C is greater than the temperature group of 35 ° C to 40 ° C, then the active component spends in the temperature range of 25 ° C to 30 ° C is greater than the temperature range of 35 ° C To 40 ° C.

Each temperature packet can be a specific number of bytes in the EEPROM, for example, three bytes. The choice of the number of bytes depends on the maximum value of a single packet. For example, three bytes are selected in this example because the maximum packet value must be about 1 million. If the active component is maintained at a constant temperature for five years, the maximum value of the grouping of the temperature must be greater than 525,600 because there will be 525,600 possible sub-time intervals in the 5-year period (24 [sub-time interval / 2 hour period] x12 [2 hour period/day] x365 [day/year] x5 [year] = 525, 600 sub-time intervals). When the active component is first activated by the end user, each temperature packet is set to zero, that is, each byte is set to zero, indicating that the active component is not in each temperature range. Spend any time. When the temperature is measured to fall within a particular temperature range, then the byte of the temperature group corresponding to the temperature range is incremented by the appropriate amount.

The time interval (ie, the memory write time interval) written between the EEPROMs depends on the desired lifetime of the active device and how many times the EEPROM can be written. For example, any given cell in the EEPROM of the selected particular wafer, when operating at 85 ° C, can be written to about 30,000 times before the cell body may fail. This means that if the EEPROM is expected to operate at 85 °C during its lifetime, the number of writes to each temperature packet should be less than 30,000 writes. The number of lifetime writes will be Reduced by high operating temperatures. For example, if the operating temperature of the EEPROM exceeds 85 ° C, the number of lifetime writes will be less than 30,000 times. This time interval is selected such that the operational lifetime of the EEPROM exceeds the operational lifetime specific safety factor of the VCSEL (or any active component being monitored). This will ensure that the EEPROM continues to record operational information about the VCSEL throughout its operational life. The appropriate safety factor used is specific to the application; however, for example, it typically falls within the range of 1.2 to 10.

If the lifetime of the active component is expected to be about five years, then the EEPROM must also operate for at least the same length of time as the VCSEL, so that the entire system component is not limited by the EEPROM. To ensure that the EEPROM can operate for five years at 85 ° C or lower operating temperature, the EEPROM should be written every two hours under the worst operating conditions (2 hours x 30,000 = 60,000) 6.8 years). The lifetime of the EEPROM may exceed five years because (1) the active component does not always operate at the same temperature during the lifetime of the active component, so more than one temperature packet will be updated, and / Or (2) the active component does not always operate at the maximum operating temperature during the lifetime of the active component, so the EEPROM can be implemented assuming that the EEPROM lifetime exceeds the lifetime of the VCSEL over the entire temperature range More write cycles. This 2-hour memory write time interval is only one possible time interval paradigm. For example, if the number of writes to the EEPROM is increased, then the memory write time interval is shortened; or, if the lifetime of the active device is expected to be longer, then the memory write time interval is Will be extended. Preferably, the memory write time interval is selected to ensure that the life of the EEPROM is greater than the life of the VCSEL.

Since the temperature greatly varies within the memory writing time interval (for example, 2 hours), it is preferable to record the particle size at a higher temperature. Recorded for temperature increase Particle size, temperature can be measured in smaller time intervals (for example, every 5 minutes) and recorded in volatile memory. That is, the memory write time interval is divided into a plurality of sub-time intervals. The temperature histogram cannot be stored in the volatile memory, because if the active component is turned off, all the data stored in the volatile memory will be lost. The volatile memory can be incorporated into the microprocessor, which is part of a system containing the active component. For example, if the sub-time intervals are 5 minutes and if the memory write time interval is two hours, then 24 temperature measurements will be attached to the EEPROM when they are written to the EEPROM. Individual temperature groupings.

An example of a temperature grouping method in accordance with a preferred embodiment of the present invention is provided in Tables A and B below. In this example, the memory write time interval is 2 hours and the sub-time interval is 5 minutes. The histogram of the EEPROM shown in Table A is the active component that has never been turned on. Therefore, all the bytes of all temperature packets are zero; and the histogram of the EEPROM shown in Table B has been activated for two hours. element. If the active component operates at 13 ° C in the first memory write time interval, then the temperature range is 10 ° C Packet #4 at T < 15 °C is incremented by 24 (Hex 18) to indicate that the active component has spent all 24 five-minute sub-time intervals operating between 10 ° C and 15 ° C, as shown in Table B. . A flowchart showing the temperature grouping method is shown in FIG.

The temperature histogram will be updated after the next two hours. For example, each temperature group that the active component is measured in the temperature range will be incremented by one in each of the five minute sub-time intervals. At any time, the temperature histogram represents the amount of time spent at each temperature range in units of five minute sub-intervals. The temperature is square The graph will then be used to estimate the effective age of the active component.

For example, the temperature packets can be larger or smaller than three bytes. For example, the number of packets can be greater or less than 22. For example, the temperature range can be greater or less than 5 °C. Any suitable coding technique (which includes a big endian or little endian) can be used to store the size of the temperature packet.

The memory write time interval, the sub-time interval, and the packet size can be optimized based on the thermal time constant of the active device, the desired active device lifetime, and the lifetime and capacity of the EEPROM. For example, if the thermal time constant of the active component is large and the temperature of the active component is slowly changed, then the memory write time interval and the sub-time interval are increased and the packet is reduced. Active components with long expected lifetimes can use longer memory write time intervals as well as sub-time intervals. High-capacity EEPROMs can support larger packet sizes. The 5-year lifetime, 2-hour memory write time interval, and 5-minute sub-time interval used above are merely examples and can be appropriately changed and optimized for various applications.

Lifetime estimation algorithm

An example of a lifetime estimation method is the Arrhenius equation, which is an empirical equation that can be used to estimate the temperature dependence of a chemical reaction. It can also be used in reliability calculations as a method of determining the effect of accelerated aging when operating at high temperatures. That is, the Arrives equation can be used to determine an effective aging acceleration factor for an active component based on an active component operating at a constant 40 ° C or a particular other reference temperature. The Arrives equation is provided in Equation 1 below, where k is the rate constant, A is the proportionality constant, E _A is the activation energy, k _B is the Boltzmann constant, and T is the open temperature ( Kelvin) is the temperature of the unit.

The activation energy E _A is usually provided by the manufacturer of the active component in the study of reliability.

The aging accelerating factor A _{F is} provided by Equation 2 below, which is defined as the rate at which aging accelerates at a high temperature operation compared to operating at a reference temperature, where t _{H is} the elevated temperature and t _{R is} the ratio Low reference temperature.

The aging accelerating factor A _F is related to t _R and the Arrhenius equation via t _H , and t _H and t _{R are} equivalent to the rate constants determined in the Arrhenius equation at their individual temperature levels. The method used to estimate the effective age of the active component relies on determining the aging acceleration factor A _{Fn of} each temperature packet T _n based on a reference temperature T _R , which can be found from Equation 3 below, wherein n is the number of groups: The temperature group T _n can be selected to be any temperature within the packet temperature range, for example, including the lowest temperature among the grouping ranges, the average temperature among the grouping ranges, and the highest temperature among the grouping ranges .

Then, by multiplying the time N _n spent at each temperature by the corresponding aging acceleration factor A _Fn and summing up the values of all of the packets, the effective age of the active component in hours is found. t _effective . The estimated effective age t _effective can be found in Equation 4 below, where N _n is the value stored in packet n and the sub-time interval is assumed to be 5 minutes:

This equation can be broadly adapted to a system that takes temperature readings every m minutes and bins the readings into b groups:

Once the estimated MTTF Effective Age _t effective, then, the active element can deduct Effective Age _t effective to estimate the remaining life of the active element. It is also possible to compare the effective age t _effective with other indicators of the component lifetime. For example, the effective age t _effective can be compared to B10, B5, or B1 life, which represent the overall 10%, 5%, or 1% failure time, respectively. In a particular application, once the active age of the active component reaches one of these lifetime indicators, it may be desirable to replace the system. Other life-cycle indicators other than those explicitly stated can also be used.

Determining the effective age t _effective and the remaining lifetime can be implemented in various ways and at various locations. In a preferred embodiment of the invention, the microprocessor shown in FIG. 4 is capable of communicating with the volatile memory, interrogating individual memory packets, and implementing the necessary calculations to determine the effective age t _effective . Once the effective age t _effectively exceeds a certain threshold, the microprocessor sends an indicator signal to the user. In another preferred embodiment of the present invention, an external component including the active component but not part of the system is capable of communicating with the volatile memory, questioning individual memory packets, and implementing to determine the effective age The necessary calculation of t _effective . Once the effective age t _effective exceeds a certain threshold, the external component provides an indicator signal to the user.

The effective age t _effective can be estimated using any other aging model, including a modified model of the model based on the Arrhenius equation and a model not derived from the Arrives equation. The effective age t _effective can be determined based on any measurable condition that would affect the age of the active component. For example, measurable conditions include humidity, temperature cycling, current, power consumption, UV exposure, ... and the like. For example, Rodriguez's model disclosed in the 14-page Parametric Survival Models published in the summer of 2010 can be used, which is hereby incorporated by reference in its entirety. The effective age t _effective can be based on temperature combined with any other measurable condition; or, can be based on only one or more measurable conditions, without regard to temperature.

In some applications, a fixed bias current is applied to the laser during the life of the active component. An aging accelerating factor based on the bias current can be used to calculate the effective age of the active component. Both the aging accelerating factor based on the bias current and the temperature-based aging accelerating factor (for example, A _{Fn in} Equation 3) can be used to determine the effective age of the active component.

In other applications, a variable bias current can be applied to the laser during the life of the active component. For example, the optical output power of a semiconductor laser typically decreases with temperature. In some applications it may be desirable to maintain a relatively constant optical output power with temperature. In such applications, the bias current provided to the jacket for the laser can be used to maintain a relatively constant optical output power as the temperature increases. Since the operation typically increases the aging acceleration factor at a high bias current in a known manner, each temperature packet will have an aging acceleration factor based on the associated bias current. Both the aging accelerating factor based on the bias current and the temperature-based aging accelerating factor (for example, A _{Fn in} Equation 3) can be used to determine the effective age of the active component. For example, the total aging acceleration factor for each temperature group can be determined by multiplying the right side of Equation 3 by the bias current based aging acceleration factor associated with each temperature group.

A particular example of a preferred embodiment of the invention will take into account the temperature because it is a measurable condition that most affects the age of the VCSEL; however, measurable conditions other than temperature may also have an effect on the aging of other active components.

It is to be understood that the foregoing description is merely illustrative of the invention. In describing a preferred embodiment of the present invention, the active component is a VCSEL, although the system is an AOC, and the measured operating parameters are temperature; however, these are only specific to the preferred embodiment of the present invention. example. The preferred embodiment of the present invention can also be applied to any system having active components that depend on a particular measurable operational parameter over its lifetime. In some embodiments, more than one operational parameter is measured and recorded, and the effective age is calculated based on the combined effects of the parameters. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to cover all such alternatives, modifications, and variations in the scope of the appended claims.

Claims (29)

An active optical cable includes: a fiber optic cable; at least one optical transducer; a first memory; a second memory; and a sensor that senses an operation of the active optical cable a parameter; and a processor coupled to the at least one optical transducer, the first memory, the second memory, and the sensor; wherein the processor: is divided into a plurality of regularities During a regular time interval of the time interval and after each of the regular sub-time intervals, a value representing a sensed operational parameter is recorded in the second memory; and at each of the regular times After the interval, the value to be recorded in the second memory is stored in the first memory. The active optical cable of claim 1, wherein: the second memory comprises a plurality of bins; and each of the packets corresponds to a value of the sensed operational parameter range. According to the active optical cable of claim 2, wherein the regular time intervals and the regular sub-time intervals are an expected number of writes of the first memory and one of the active optical cables The life expectancy is based. An active optical cable according to item 2 of the patent application, wherein the operating parameter is temperature. An active optical cable according to claim 2, wherein the processor is in the second memory by incrementing a grouping value of a packet corresponding to a numerical range of the sensed operating parameter by one A value indicative of the sensed operational parameter is recorded, wherein the range of values of the sensed operational parameter includes a value indicative of the sensed operational parameter. The active optical cable of claim 5, wherein the first memory comprises a plurality of packets corresponding to the packets in the second memory. An active optical cable according to claim 6 wherein the processor adds a packet value of each of the second memories to a corresponding packet previously stored in the first memory. The value recorded in the second memory is stored in the first memory in the corresponding packet value. The active optical cable of claim 7, wherein the processor calculates an effective age of the active optical cable based on a packet value of a packet stored in the first memory. An active optical cable according to claim 8 wherein the processor calculates the effective age based only on the grouping value of the packets stored in the first memory. An active optical cable according to claim 8 wherein the processor provides an indicator signal if the effective age is above a critical value. An active optical cable according to claim 7 wherein: the operating parameter is temperature, and each of the groups represents a temperature range; and the processor calculates the active optical using the following equation An effective age of the cable t _effective : among them, m is the time of the regular sub-time interval in minutes, b is the number of packets, N _n is the value stored in packet n, E _A is the activation energy, k _B is the Boltzmann constant, and T _n is The grouping temperature, and T _R is the reference temperature. The active optical cable of claim 2, wherein the processor resets the value stored in the second memory after each of the regular time intervals. An active optical cable according to claim 2, wherein the processor calculates an effective age of the active optical cable based on a value stored in the first memory. The active optical cable according to claim 2, wherein the first memory system is a non-volatile memory, and the second memory system is a volatile memory. An active optical cable according to item 2 of the patent application, wherein the first memory system EEPROM. A method of calculating an effective age of an active optical cable, the active optical cable comprising a fiber optic cable, at least one optical transducer, a first memory, and a second memory, the method comprising: being divided into Sensing an operational parameter of the active optical cable during a regular time interval of the plurality of regular sub-time intervals and after each of the regular sub-time intervals and recording in the second memory indicates that one is sensed a value of the operational parameter; After each of the regular time intervals, the value recorded in the second memory is stored in the first memory; and based on the value stored in the first memory To calculate the effective age of the active optical cable. The method of claim 16, wherein: the second memory comprises a plurality of bins; and each of the packets corresponds to a range of values of the sensed operational parameter. The method of claim 17, wherein the regular time intervals and the regular sub-time intervals are an expected number of writes of the first memory and an expected lifetime of the active optical cable Based on. The method of claim 17, wherein the operating parameter is temperature. The method of claim 17, wherein the numerical value indicating the sensed operational parameter is recorded in the second memory to include a grouping of packets corresponding to a range of values of the sensed operational parameter The value is incremented by one, wherein the range of values of the sensed operational parameter includes a value indicative of the sensed operational parameter. The method of claim 20, wherein the first memory comprises a plurality of packets corresponding to the packets in the second memory. The method of claim 21, wherein storing the value recorded in the second memory in the first memory comprises grouping each of the second memories The value is added to the corresponding packet value previously stored in the corresponding packet in the first memory. The method of claim 22, wherein the active optical cable is calculated The effective age is based on the grouping value of the packets stored in the first memory. The method of claim 23, wherein calculating the effective age is based only on a grouping value of a packet stored in the first memory. The method of claim 23, further comprising providing an indicator signal if the effective age is above a critical value. The method of claim 22, wherein: the operating parameter is temperature, and each of the groups represents a temperature range; and calculating the effective age of the active optical cable comprises utilizing the following equation: among them, t _effective is the effective age of the active optical cable, m is the time in the regular sub-time interval in minutes, b is the number of packets, N _n is the value stored in the packet n, and E _A is the activation energy, k _B is the Boltzmann constant, T _n is the grouping temperature, and T _R is the reference temperature. The method of claim 17, further comprising resetting the value stored in the second memory after each of the regular time intervals. The method of claim 17, wherein the first memory system is a non-volatile memory and the second memory system is a volatile memory. The method of claim 17, wherein the first memory system EEPROM.