Multi-channel voltage generating circuit for testing optical switch array device and control method thereof

Abstract

The embodiment of the present disclosure provides a multi-channel voltage generating circuit for testing an optical switch array device and a control method thereof. The circuit includes a main control module, a plurality of digital-to-analog conversion modules, a plurality of front switching switch modules, and a rear switching switch module connected in sequence; the digital-to-analog conversion module converts the digital signal of the main control module into a multi-channel analog voltage signal; the output voltages of each digital-to-analog conversion module are not equal; each front switching switch module is set corresponding to each digital-to-analog conversion module to control the on and off of the multi-channel analog voltage signal; the rear switching switch module is provided with a plurality of voltage output channels; the rear switching switch module is used to select the output voltage of each voltage output channel; the main control module is electrically connected to a plurality of front switching switch modules and a rear switching switch module, respectively, to control a plurality of front switching switch modules and a rear switching switch module. The circuit structure disclosed in the present disclosure is simple, the control difficulty is low, the output voltage jump is fast, and the cost is low, which improves the economy and efficiency of the optical switch array device test.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the field of power electronics technology, and specifically relate to a multi-channel voltage generating circuit for testing an optical switch array device and a control method thereof. Background Art

[0002] High-speed silicon-based optical switches are the most basic and core components in optical switching systems. In the future, optical switching must meet the requirements of high-speed, large-capacity and low-latency switching, and fast-switching optical switches are essential. As the optical switch matrix composed of silicon-based optical switches as the basic unit is increasingly used in all-optical communication networks, the localization speed of silicon-based optical switch array devices is also accelerating, resulting in an increasing demand for testing such devices. Silicon-based optical switches are voltage-controlled devices that require precise voltage drive to work properly. When testing optical switch array devices, the tester is often required to have the ability to output multiple different precise voltages.

[0003] The main control device of this type of test circuit is a programmable device such as MCU or FPGA, which is connected to multiple digital-to-analog converters (DAC) through SPI, I2C or parallel bus to control the digital-to-analog converter to generate a suitable voltage, which is then amplified by an amplifier or a voltage follower circuit to increase the driving force, and then the output is used to drive the silicon-based optical switch to be tested.

[0004] When the optical switch array to be tested is small and the speed requirement is low, the above-mentioned multi-channel voltage generation circuit can indeed meet the test requirements. However, as the scale of the optical switch array becomes larger and the speed requirement becomes faster, the inherent defects of this circuit begin to slowly emerge and eventually become unacceptable.

[0005] There are few studies on the multi-channel voltage generation circuit architecture for testing optical switch array devices. Reference [1]: "Design of driving system for polymer optical waveguide switch array", Journal of Jilin University, Vol. 40, No. 2, March 2022. This document adopts the traditional driving method and uses an independent DAC to drive each voltage output port. This solution has at least the following two disadvantages: 1. The number of DACs required is the same as the number of output ports, and the circuit is complex, large and expensive; 2. The steepness of the output voltage jump edge is insufficient. Reference [2]: "A design method for optical switch array drive control circuit", Journal of Xichang University, Vol. 37, No. 2, June 2023. This document adopts an improved driving method and uses two digital potentiometers to drive one voltage output port, which can improve the steepness of the voltage jump edge of the traditional circuit when changing the output to a certain extent. However, the number of digital potentiometers required for this technical solution is as much as twice the number of voltage output ports, which greatly increases the difficulty of control and the complexity of the system. When more voltage output ports are required, it is basically impossible to achieve.

[0006] In general, the above traditional multi-channel voltage generating circuits all have the following disadvantages:

[0007] 1. The number of communication ports of the digital-to-analog converter is huge

[0008] Each voltage output port of this voltage generator requires an independent DAC to generate voltage. However, even if a single-chip 16-channel DAC device is used for design, when it is necessary to test an optical switch array of up to 1,000 or even 2,000 channels, dozens or even more than a hundred DAC chips are required, and each chip needs to be connected to the master device through a dedicated control bus. In reality, a master device often has only a few dedicated bus interfaces. In order to connect an astonishing number of DAC chips, multiple master devices have to be added, which brings great difficulties to the design and use of the tester.

[0009] 2. The output voltage changes slowly

[0010] When the state of the optical switch needs to be changed, the output voltage of the voltage generating device needs to be changed. This can be accomplished by writing different data into the DAC by the main control device. However, in reality, due to the limitations of the DAC device principle, its output voltage cannot jump to the specified value immediately after receiving the new data, but can only slowly approach the specified value. The specific change time required depends on the specific device model used, usually between tens of μs and hundreds of ns, and the voltage jump time required for a high-speed optical switch is often only 10ns. This slow voltage change speed greatly reduces the accuracy of the test results.

[0011] 3. The test equipment is bulky and expensive

[0012] Large-scale optical switch arrays require a large number of DAC chips to drive them, and these DAC chips have to be equipped with a large number of main control chips and other auxiliary circuits. In order to provide sufficient power to this complex circuit, the power supply circuit must also increase the number and size of power supplies. This makes the entire test device bulky and expensive. Summary of the invention

[0013] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art, and provide a multi-channel voltage generating circuit for testing an optical switch array device and a control method thereof.

[0014] One aspect of the present disclosure provides a multi-channel voltage generating circuit for testing an optical switch array device, the circuit comprising a main control module, a plurality of digital-to-analog conversion modules, a plurality of front switching switch modules, and a rear switching switch module connected in sequence;

[0015] The digital-to-analog conversion module is used to convert the digital signal of the main control module into a multi-channel analog voltage signal; the output voltages of the digital-to-analog conversion modules are not equal;

[0016] Each of the front switching switch modules is correspondingly arranged with each of the digital-to-analog conversion modules, and is used to control the on and off of the multi-channel analog voltage signal;

[0017] The rear switching switch module is provided with a plurality of voltage output channels; the rear switching switch module is used to select the output voltage of each of the voltage output channels;

[0018] The main control module is electrically connected to the plurality of front switch modules and the rear switch module respectively, and is used to control the plurality of front switch modules and the rear switch module.

[0019] Furthermore, the circuit also includes a voltage follower module;

[0020] The voltage follower module is arranged between the front switching switch module and the rear switching switch module, and is used for output buffering of multi-channel analog voltage signals.

[0021] Further, the voltage follower module includes a plurality of voltage followers;

[0022] Each of the voltage followers is respectively arranged corresponding to the analog voltage signal of each channel.

[0023] Furthermore, the circuit also includes a voltage maintaining module;

[0024] The voltage maintaining module is arranged between the front switching module and the voltage follower module, and is used for maintaining the output level of the voltage follower module.

[0025] Further, the voltage maintaining module includes a plurality of voltage maintaining capacitors;

[0026] Each of the voltage holding capacitors is respectively arranged corresponding to the analog voltage signal of each channel.

[0027] Further, the front switching switch module includes a single-pole multi-throw analog switch;

[0028] The single-pole multi-throw analog switch is used to selectively control the conduction of the analog voltage signal of the corresponding channel.

[0029] Further, the rear switching switch module includes a plurality of single-pole multi-throw analog switches;

[0030] Each of the single-pole multi-throw analog switches is respectively arranged corresponding to each of the voltage output channels, and is used to select the output voltage corresponding to the voltage output channel.

[0031] Furthermore, the main control module is MCU or FPGA.

[0032] Another aspect of the present disclosure provides a control method for a multi-channel voltage generating circuit for testing an optical switch array device. Based on the multi-channel voltage generating circuit for testing an optical switch array device described above, the control method includes:

[0033] Using a first digital-to-analog conversion module to convert the digital signal of the main control module into a first voltage required by a voltage output channel;

[0034] Using a second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by a voltage output channel;

[0035] Using the main control module to control the front switch module and the rear switch module to conduct the first digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a first voltage;

[0036] The main control module is used to control the front switching switch module and the rear switching switch module to respectively turn on the second digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a second voltage.

[0037] Furthermore, when the circuit further includes a voltage maintaining module, the control method includes:

[0038] Use a first digital-to-analog conversion module to convert the digital signal of the main control module into a first voltage required by a voltage output channel, and use the main control module to control the front switching module to turn on the first digital-to-analog conversion module and the first voltage holding module, so that the first voltage holding module is charged;

[0039] Use a second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by the voltage output channel, and use the main control module to control the front switching switch module to turn on the second digital-to-analog conversion module and the second voltage holding module, so that the second voltage holding module is charged;

[0040] Using the main control module to control the rear switching switch module to conduct the first voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a first voltage;

[0041] The main control module is used to control the rear switching switch module to conduct the second voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a second voltage.

[0042] A multi-channel voltage generating circuit for testing an optical switch array device and a control method thereof according to an embodiment of the present disclosure use a multi-channel plus front / rear switching switch architecture design to drive a multi-channel voltage output port, which fully meets the requirement of a steep voltage jump edge in the optical switch array device testing process, and at the same time realizes the multi-channel voltage output expected by a large-scale optical switch test circuit. The circuit has a simple circuit structure, low control difficulty, fast output voltage jump, and low cost, which improves the economy and efficiency of optical switch array device testing and meets actual application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of an existing multi-channel voltage generating circuit;

[0044] Figure 2 This is a schematic diagram of the structure of a multi-channel voltage generating circuit for testing an optical switch array device according to an embodiment of the present disclosure;

[0045] Figure 3 It is a flow chart of a method for controlling a multi-channel voltage generating circuit for testing an optical switch array device according to another embodiment of the present disclosure;

[0046] Figure 4 The present invention is a flowchart of a method for controlling a multi-channel voltage generating circuit for testing an optical switch array device when the circuit includes a voltage holding module in another embodiment of the present invention. DETAILED DESCRIPTION

[0047] like Figure 1 The figure shows an existing traditional multi-channel voltage generation circuit, which uses an independent DAC (digital-to-analog converter) to drive each voltage output channel. The number of DACs required is the same as the number of output ports. The circuit is complex, large and expensive, and the steepness of the output voltage jump edge is insufficient, which cannot meet the testing requirements of high-speed, large-scale optical switch array devices.

[0048] The existing improved voltage generating circuit adds two digital potentiometers to the voltage output port on the basis of the traditional voltage generating circuit, thereby improving the steepness of the voltage jump edge when changing the output. However, the number of digital potentiometers required is as much as twice the number of voltage output ports, which greatly increases the difficulty of control, the complexity of the system and the cost. It is basically impossible to achieve when there are more voltage output ports.

[0049] In order to make up for the inherent defects of the traditional multi-channel voltage generating circuit, the object of the present application is to provide a new multi-channel voltage generating circuit that can meet the needs of such testing according to the characteristics of the optical switch array device testing.

[0050] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0051] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the present disclosure.

[0052] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0053] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another component. Therefore, the first component discussed below can be referred to as the second component without departing from the teachings of the concepts of the present disclosure. As used in this disclosure, the term "and / or" includes any one of the associated listed items and all combinations of one or more.

[0054] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present disclosure, and therefore cannot be used to limit the protection scope of the present disclosure.

[0055] An embodiment of the present disclosure provides a multi-channel voltage generating circuit for testing an optical switch array device, the circuit comprising a main control module, a plurality of digital-to-analog conversion modules, a plurality of front switching switch modules, and a rear switching switch module connected in sequence. The digital-to-analog conversion module is used to convert the digital signal of the main control module into a multi-channel analog voltage signal; the output voltages of the digital-to-analog conversion modules are not equal. Each of the front switching switch modules is arranged corresponding to each of the digital-to-analog conversion modules, and is used to control the on and off of the multi-channel analog voltage signal. The rear switching switch module is provided with a plurality of voltage output channels; the rear switching switch module is used to select the output voltage of each of the voltage output channels. The main control module is electrically connected to the plurality of front switching switch modules and the rear switching switch modules, respectively, and is used to control the plurality of front switching switch modules and the rear switching switch modules.

[0056] Specifically, Figure 2 As shown, the technical solution of the present disclosure is described by taking two DACs and four voltage output channels as examples. The main control module M1 is a programmable device such as an MCU or FPGA, which is connected to two digital-to-analog conversion modules DAC1 and DAC2 through a communication bus, and the main control module M1 controls the output signals of the digital-to-analog conversion modules DAC1 and DAC2. The digital-to-analog conversion modules DAC1 and DAC2 are controlled by the main control module M1, and each converts the digital signal of the main control module M1 into a four-channel analog voltage signal. The output ends of the digital-to-analog conversion modules DAC1 and DAC2 are respectively connected to two front switching switch modules S1 and S2, and the two front switching switch modules S1 and S2 each control the on and off of the four-channel analog voltage signals output by the corresponding digital-to-analog conversion modules DAC1 and DAC2. The rear switching switch module S3 is provided with four voltage output channels, and the front switching switch modules S1 and S2 each output four-channel analog voltage signals to the rear switching switch module S3, and the rear switching switch module S3 selectively controls the analog voltage signals output by each voltage output channel. The front switch modules S1, S2 and the rear switch module S3 are all electrically connected to and controlled by the main control module M1.

[0057] For example, Figure 2 As shown, the circuit further includes a voltage follower module M2. The voltage follower module M2 is disposed between the front switch modules S1 and S2 and the rear switch module S3, and includes a plurality of voltage followers AMP for outputting buffers for multi-channel analog voltage signals.

[0058] Specifically, the voltage follower AMP can also be called a voltage buffer, a unity gain amplifier or an isolation amplifier, which realizes the matching between the output voltage and the input voltage based on the negative feedback principle, and is mainly composed of an amplifier and a feedback circuit. The output signal of the amplifier is compared with the input signal through the feedback circuit, and the difference is fed back to the input end of the amplifier, so as to maintain the stability of the output voltage. Each of the voltage follower AMPs is respectively set corresponding to the analog voltage signal of each channel, and a total of eight channels output by the front switching switch modules S1 and S2 are all set with voltage followers AMP, so as to buffer the analog voltage signal output by each channel and maintain the stability when the voltage is input and the switch module S3 is switched.

[0059] For example, Figure 2 As shown, the circuit further includes a voltage maintaining module M3. The voltage maintaining module M3 is arranged between the front switching modules S1 and S2 and the voltage follower module M2, and is used to maintain the output level of the voltage follower module M2.

[0060] Specifically, the voltage holding module M3 includes a plurality of voltage holding capacitors, each of which is set corresponding to the analog voltage signal of each channel, that is, the four channels output by the front switching switch module S1 are respectively set to voltage holding capacitors C11~C14, and the four channels output by the front switching switch module S2 are respectively set to voltage holding capacitors C21~C24. When the voltage holding capacitors are charged, the corresponding analog voltage signals can be provided to the corresponding channels, thereby maintaining the output level of the corresponding voltage follower AMP.

[0061] For example, Figure 2 As shown, the front switch modules S1 and S2 include a single-pole multi-throw analog switch. The single-pole multi-throw analog switch is used to selectively control the conduction of the analog voltage signal of the corresponding channel.

[0062] Specifically, the single-pole multi-throw analog switch in the front switching switch module S1 includes four branch ports S11, S12, S13, and S14, each connected to a channel of the analog voltage signal, and its common end is connected to the output end of the digital-to-analog conversion module DAC1. The control end of the front switching switch module S1 is connected to the main control module M1. Under the control of the main control module M1, the front switching switch module S1 selectively connects one of the four branch ports S11, S12, S13, and S14 to its common end as needed, thereby connecting the analog voltage signal of the corresponding channel. Similarly, the single-pole multi-throw analog switch in the front switching switch module S2 includes four branch ports S21, S22, S23, and S24, each of which is connected to a channel of the analog voltage signal, and its common end is connected to the output end of the digital-to-analog conversion module DAC2. The control end of the front switching switch module S2 is connected to the main control module M1. Under the control of the main control module M1, the front switching switch module S2 selectively connects one of the four branch ports S21, S22, S23, and S24 to its common end as needed, thereby connecting the analog voltage signal of the corresponding channel.

[0063] For example, Figure 2 As shown, the rear switching switch module S3 includes four single-pole multi-throw analog switches S31, S32, S33, and S34. Each of the single-pole multi-throw analog switches is respectively arranged corresponding to each of the voltage output channels, and is used to select the output voltage corresponding to the voltage output channel.

[0064] Specifically, the common end of each single-pole multi-throw analog switch S31, S32, S33, and S34 is connected to the voltage output channels 1, 2, 3, and 4, respectively. Taking the voltage output channel 1 as an example, the analog voltage signal output by the shunt port S11 of the front switching switch module S1 and the analog voltage signal output by the shunt port S21 of the front switching switch module S2 are respectively connected to the shunt ports a and b of the single-pole multi-throw analog switch S31 in the rear switching switch module S3. When the single-pole multi-throw analog switch S31 in the rear switching switch module S3 connects its common end to its shunt port a, the voltage output channel 1 outputs the analog voltage signal output by the shunt port S11 of the front switching switch module S1; when the shunt port a of the single-pole multi-throw analog switch S31 is switched to the shunt port b, the voltage output channel 1 outputs the analog voltage signal output by the shunt port S21 of the front switching switch module S2, completing the rapid switching of the output voltage. The control end of the rear switching switch module S3 is connected to the main control module M1, and the switching of the above-mentioned single-pole multi-throw analog switches is controlled by the main control module M1.

[0065] It is understandable that the above embodiment only illustrates a circuit for controlling a four-channel output voltage using dual DACs and several analog switches. Based on the same principle, it is completely feasible to use two DACs to complete 8 or even 16 channels of voltage output simply by increasing the number of shunt ports of the front switching switch, the number of connected capacitors and voltage followers, and the number of channels of the rear switching analog switch. Of course, in actual operation, the specific number of voltage output channels that can correspond to each of the two DACs depends on the characteristics of the optical switch device to be tested and the test requirements. Obviously, the number cannot be increased indefinitely to avoid the adverse consequences of a decrease in the speed of voltage group change and a deterioration in the stability of the output voltage. In the case of determining the number of voltage output channels controlled by each of the two DAC devices, as long as the number of DACs, analog switches, capacitors and followers continues to be increased in sets, the number of voltage output channels can be doubled.

[0066] A multi-channel voltage generating circuit for testing an optical switch array device according to an embodiment of the present disclosure, although the front / rear switching analog switch and capacitor are added, the DAC devices are greatly reduced. Compared with the dedicated bus required to control the DAC device, only ordinary IO ports are required to control the analog switch. And when the voltage output channel increases, the control line of the analog switch can be reused. For example, in most cases, the control lines of the front switching switch modules S1 and S2 can be reused, that is, when DAC1 is generating voltage U11 and S11 in S1 is turned on, DAC2 can also generate U21 at the same time and S21 in S2 can also be turned on synchronously; similarly, for the rear switching switch module S3, there is no problem in connecting the common end of each voltage output channel to each branch end a or b at the same time. Therefore, compared with the traditional circuit, the circuit structure of the present disclosure is simpler and easier to control.

[0067] Secondly, due to the characteristics of the optical switch itself, the jump edge of the control voltage is expected to be steeper during its switching process. For traditional voltage generating circuits, the rate of change of the output voltage when changing the output voltage can only depend on the output response characteristics of the selected DAC device. In reality, there are very few DAC devices that can complete the output change within 10ns. In contrast, the next set of control voltages required by the optical switch in the circuit disclosed in the present invention is generated by the DAC in the non-output state and can be pre-stored in the corresponding holding capacitor. Therefore, the jump speed of the output voltage depends only on the switching speed of the analog switch rather than the output characteristics of the DAC device. In reality, even a commonly used analog switch can complete the channel switching operation within 10ns, making the jump edge of the output voltage much steeper than that of the traditional circuit.

[0068] Finally, since the circuit disclosed in the present invention greatly reduces the number of DAC devices, the number of main control chips can also be reduced accordingly. In addition, compared with DAC devices, the cost and power consumption of analog switches are usually only one tenth to one hundredth of the former. Therefore, after removing a large number of DAC devices, the device cost can be greatly reduced, and the power supply circuit can also be greatly simplified. When the required voltage output channels increase further, the complexity and production cost of the circuit disclosed in the present invention will also be much lower than that of traditional circuits.

[0069] When using an optical routing network equipped with an optical switch array chip and a data center optical interconnect product, a multi-channel voltage generating circuit for testing an optical switch array device according to an embodiment of the present disclosure is used. The circuit structure is simpler, more channels can be controlled, and an output voltage with a faster jump can be generated. It can meet the system design requirements of high-speed, large-capacity and low-latency optical switching in the future, and realize a fast-switching optical switch. By adding front and back switching analog switches and capacitors, the number of digital-to-analog conversion devices can be greatly reduced, the number of controllable optical switch channels can be increased, the multiplexing efficiency of the device can be increased, and lower control difficulty and device processing costs can be achieved.

[0070] In summary, a multi-channel voltage generating circuit for testing an optical switch array device according to an embodiment of the present disclosure uses a multi-channel plus front / rear switching switch architecture design to drive a multi-channel voltage output port, which fully meets the requirement of a steep voltage jump edge in the optical switch array device testing process, and at the same time realizes the multi-channel voltage output expected by a large-scale optical switch test circuit. The circuit structure is simple, the control difficulty is low, the output voltage jump is fast, and the cost is low, which improves the economy and efficiency of the optical switch array device testing and meets the actual application needs.

[0071] like Figure 3 As shown, another embodiment of the present disclosure provides a control method for a multi-channel voltage generating circuit for testing an optical switch array device, based on the multi-channel voltage generating circuit for testing an optical switch array device described in the previous embodiment, characterized in that the control method includes:

[0072] Step S301: Use a first digital-to-analog conversion module to convert a digital signal of the main control module into a first voltage required by a voltage output channel.

[0073] Specifically, refer to Figure 2 The technical solution of the present disclosure is described by taking two DACs and four voltage output channels as an example. When the voltage output channel 1 needs to output voltage, the main control module M1 drives the first digital-to-analog conversion module DAC1 to generate the first voltage U11 that the voltage output channel 1 needs to output.

[0074] Step S302: Use a second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by a voltage output channel.

[0075] Specifically, on the basis of the previous step S301 , the main control module M1 drives the second digital-to-analog conversion module DAC2 to generate the second voltage U21 that the voltage output channel 1 needs to output.

[0076] Step S303: Use the main control module to control the front switch module and the rear switch module to respectively turn on the first digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a first voltage.

[0077] Specifically, the main control module M1 controls S11 in the front switching switch module S1 to be turned on (based on the fact that the front switching switch module S1 is a single-pole multi-throw switch, S12~S14 will be automatically disconnected at this time, and the same reason will not be repeated below), and at the same time controls the common end of the single-pole double-throw switch S31 in the rear switching switch module S3 to be connected to the input end a, and the voltage output channel 1 will immediately output the first voltage U11.

[0078] Step S304: Use the main control module to control the front switch module and the rear switch module to respectively turn on the second digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a second voltage.

[0079] Specifically, after the above steps, the voltage output channel 1 currently outputs the first voltage U11. At this time, when the main control module M1 receives an external instruction requiring the voltage output channel 1 to output the second voltage U21, it immediately turns on S21 in the front switching switch module S2, and changes the common end of S31 in the rear switching switch module S3 from end a to end b, and the voltage output channel 1 will immediately change to output the second voltage U21.

[0080] When the remaining voltage output channels 2 to 4 need to output voltage, the multi-channel voltage generating circuit for testing the optical switch array device is controlled in accordance with the same method and steps as above, which will not be described in detail in this article.

[0081] For example, Figure 4 As shown, when the circuit further includes a voltage maintaining module, the control method includes:

[0082] Step S401: Use the first digital-to-analog conversion module to convert the digital signal of the main control module into the first voltage required by the voltage output channel, and use the main control module to control the front switching switch module to turn on the first digital-to-analog conversion module and the first voltage maintaining module to charge the first voltage maintaining module.

[0083] Specifically, refer to Figure 2When the voltage output channels 1 to 4 need to output voltage, the main control module M1 first drives the first digital-to-analog conversion module DAC1 to generate the voltage U11 required for the output of channel 1, then turns on S11 in the front switching module S1, and waits for the capacitor C11 in the voltage holding module M3 to complete charging. The main control module M1 then drives the first digital-to-analog conversion module DAC1 to generate the first voltage U12 required for the output of channel 2, turns on S12 in the front switching module S1, and waits for the capacitor C12 to complete charging. This is repeated by analogy until the capacitors C11 to C14 are respectively charged with the corresponding first voltages U11 to U14 required for the output of channels 1 to 4.

[0084] Step S402: Use the second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by the voltage output channel, and use the main control module to control the front switching switch module to turn on the second digital-to-analog conversion module and the second voltage maintaining module to charge the second voltage maintaining module.

[0085] Specifically, while the voltage output channels 1-4 obtain the corresponding first group of voltages U11-U14, the main control module M1 will also control the second digital-to-analog conversion module DAC2 and the front switching module S2 to generate the second group of output voltages U21-U24 and charge them into the capacitors C21-C24.

[0086] Step S403: Use the main control module to control the rear switching switch module to turn on the first voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a first voltage.

[0087] Specifically, the main control module M1 controls the respective common terminals of the rear switching switch module S3 to be connected to the input terminal a, and it is obvious that the voltage output channels 1 to 4 will immediately output respective first voltages U11 to U14. Thereafter, the main controller continuously loops and executes the same operation in step S401, continuously generates voltages U11 to U14 using the first digital-to-analog conversion module DAC1, and repeatedly charges the capacitors C11 to C14 using the switching action of S11 to S14 in the front switching switch module S1, thereby preventing the voltage on the capacitors C11 to C14 from dropping due to leakage or absorption by the voltage follower AMP.

[0088] Step S404: Use the main control module to control the rear switching switch module to turn on the second voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a second voltage.

[0089] Specifically, when the main control module M1 receives an external instruction to output the second set of voltages, it immediately changes the common terminals in the rear switching switch module S3 from terminal a to terminal b, and the voltage output channels 1 to 4 will also immediately change to output the corresponding second set of voltages U21 to U24.

[0090] Similarly, after the voltage output channels 1~4 output the second group of voltages U21~U24, the main control module M1 can re-control the first digital-to-analog conversion module DAC1 and the front switching switch module S1 to generate the third group of output voltages U31~U34 and charge them into the capacitors C11~C14. When the main control module M1 receives an external instruction to output the third group of voltages, it changes the common ends in the rear switching switch module S3 from the b end to the a end, and the voltage output channels 1~4 can immediately output the third group of voltages U31~U34.

[0091] It is understandable that the above embodiment only illustrates a circuit for controlling a four-channel output voltage using dual DACs and several analog switches. Based on the same principle, it is completely feasible to use two DACs to complete 8 or even 16 channels of voltage output simply by increasing the number of shunt ports of the front switching switch, the number of connected capacitors and voltage followers, and the number of channels of the rear switching analog switch. Of course, in actual operation, the specific number of voltage output channels that can correspond to each of the two DACs depends on the characteristics of the optical switch device to be tested and the test requirements. Obviously, the number cannot be increased indefinitely to avoid the adverse consequences of a decrease in the speed of voltage group change and a deterioration in the stability of the output voltage. In the case of determining the number of voltage output channels controlled by each of the two DAC devices, as long as the number of DACs, analog switches, capacitors and followers continues to be increased in sets, the number of voltage output channels can be doubled.

[0092] A multi-channel voltage generating circuit control method for testing an optical switch array device according to an embodiment of the present disclosure uses a multi-channel plus front / rear switching switch architecture design to drive a multi-channel voltage output port, which fully meets the requirement of a steep voltage jump edge in the optical switch array device testing process, and at the same time realizes the multi-channel voltage output expected by a large-scale optical switch test circuit. The circuit structure is simple, the control difficulty is low, the output voltage jump is fast, and the cost is low, which improves the economy and efficiency of the optical switch array device testing and meets the actual application needs.

[0093] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A multi-channel voltage generating circuit for testing an optical switch array device, characterized in that: The circuit includes a main control module, a plurality of digital-to-analog conversion modules, a plurality of front switching switch modules, a voltage holding module, a voltage follower module and a rear switching switch module connected in sequence; The digital-to-analog conversion module is used to convert the digital signal of the main control module into a multi-channel analog voltage signal; the output voltages of the digital-to-analog conversion modules are not equal; Each of the front switching switch modules is correspondingly arranged with each of the digital-to-analog conversion modules, and is used to control the on and off of the multi-channel analog voltage signal; The voltage maintaining module is arranged between the front switching module and the voltage follower module, and is used to maintain the output level of the voltage follower module; The voltage follower module is arranged between the voltage holding module and the post-switching switch module, and is used for outputting and buffering multi-channel analog voltage signals; The rear switching switch module is provided with a plurality of voltage output channels; the rear switching switch module is used to select the output voltage of each of the voltage output channels; The main control module is electrically connected to the plurality of front switch modules and the rear switch module respectively, and is used to control the plurality of front switch modules and the rear switch module.

2. The circuit according to claim 1, characterized in that The voltage follower module includes a plurality of voltage followers; Each of the voltage followers is respectively arranged corresponding to the analog voltage signal of each channel.

3. The circuit according to claim 1, characterized in that The voltage maintaining module includes a plurality of voltage maintaining capacitors; Each of the voltage holding capacitors is respectively arranged corresponding to the analog voltage signal of each channel.

4. The circuit according to claim 1, characterized in that The front switching switch module includes a single-pole multi-throw analog switch; The single-pole multi-throw analog switch is used to selectively control the conduction of the analog voltage signal of the corresponding channel.

5. The circuit according to claim 1, characterized in that The rear switching switch module includes a plurality of single-pole multi-throw analog switches; Each of the single-pole multi-throw analog switches is respectively arranged corresponding to each of the voltage output channels, and is used to select the output voltage corresponding to the voltage output channel.

6. The circuit according to any one of claims 1 to 5, characterized in that: The main control module is MCU or FPGA.

7. A control method for a multi-channel voltage generating circuit for testing an optical switch array device, based on the multi-channel voltage generating circuit for testing an optical switch array device according to any one of claims 1 to 6, characterized in that: The control method comprises: Using a first digital-to-analog conversion module to convert the digital signal of the main control module into a first voltage required by a voltage output channel; Using a second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by a voltage output channel; Using the main control module to control the front switch module and the rear switch module to conduct the first digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a first voltage; The main control module is used to control the front switching switch module and the rear switching switch module to respectively turn on the second digital-to-analog conversion module and the voltage output channel, so that the voltage output channel outputs a second voltage.

8. The control method according to claim 7, characterized in that: When the circuit further includes a voltage maintaining module, the control method includes: Use a first digital-to-analog conversion module to convert the digital signal of the main control module into a first voltage required by a voltage output channel, and use the main control module to control the front switching module to turn on the first digital-to-analog conversion module and the first voltage holding module, so that the first voltage holding module is charged; Use a second digital-to-analog conversion module to convert the digital signal of the main control module into a second voltage required by the voltage output channel, and use the main control module to control the front switching switch module to turn on the second digital-to-analog conversion module and the second voltage holding module, so that the second voltage holding module is charged; Using the main control module to control the rear switching switch module to conduct the first voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a first voltage; The main control module is used to control the rear switching switch module to conduct the second voltage maintaining module and the voltage output channel, so that the voltage output channel outputs a second voltage.

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