CN109217272B - APD optical module and protection circuit and protection method thereof - Google Patents
APD optical module and protection circuit and protection method thereof Download PDFInfo
- Publication number
- CN109217272B CN109217272B CN201811320162.8A CN201811320162A CN109217272B CN 109217272 B CN109217272 B CN 109217272B CN 201811320162 A CN201811320162 A CN 201811320162A CN 109217272 B CN109217272 B CN 109217272B
- Authority
- CN
- China
- Prior art keywords
- current
- circuit
- current value
- apd
- resistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Light Receiving Elements (AREA)
Abstract
The invention discloses a protection circuit of an APD optical module, which comprises: the current sampling circuit is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit; the control unit is connected with the current sampling circuit and used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value; the shunt circuit is used for conducting the first end and the second end of the shunt circuit after receiving a control signal, and reducing the voltage of the transformation circuit acting on the APD tube core so as to reduce the current of the APD tube core. By applying the scheme of the invention, the damage of the APD tube core caused by overcurrent can be effectively protected. The invention also discloses an APD optical module and a protection method thereof, and the APD optical module has corresponding effects.
Description
Technical Field
The invention relates to the technical field of optical modules, in particular to an APD optical module and a protection circuit and a protection method thereof.
Background
In the process of testing or practical application of an optical module, there may be a limit test condition or an artificial misoperation, and when an optical module is an APD (avalanche photodiode) optical module, a large photocurrent may be generated when a strong light is incident to a receiving end of the optical module. And when the generated photocurrent exceeds the maximum current allowed by the APD die, the APD die can be damaged.
In order to avoid damage of an excessive photocurrent to an APD die, a current limiting resistor is usually arranged in an existing APD optical module, after the current limiting resistor is added at an output end of a DC-DC circuit, when strong light is incident to the optical module, due to voltage division of the current limiting resistor, bias voltage of the DC-DC circuit acting on the APD die can be reduced, so that gain of the APD die is reduced, and the purpose of reducing current is achieved. However, such a scheme can only avoid the damage of the APD die to a certain extent, and in some cases, for example, in the cases where the bias voltage output by the DC-DC circuit is too high, the illumination intensity is too large, the maximum ac allowed by the APD die is small, and the like, the current in the APD die may still exceed the allowed maximum current, which may cause the damage of the APD die, that is, the damage of the APD optical module.
In summary, how to further avoid damage to an APD die in an APD optical module due to an overcurrent is a technical problem that needs to be solved by those skilled in the art.
Disclosure of Invention
The invention aims to provide an APD optical module, a protection circuit and a protection method thereof, so as to effectively avoid damage of an APD tube core in the APD optical module caused by overcurrent.
In order to solve the technical problems, the invention provides the following technical scheme:
a protection circuit for an APD optical module, comprising:
the current sampling circuit is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit;
the control unit is connected with the current sampling circuit and used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value;
the first end of the shunt circuit is connected with the input end of the APD tube core of the avalanche photodiode, the second end of the shunt circuit is grounded, the control end of the shunt circuit is connected with the control unit, the shunt circuit is used for conducting the first end and the second end of the shunt circuit after receiving the control signal, and the voltage of the transformation circuit acting on the APD tube core is reduced so as to reduce the current of the APD tube core.
Preferably, the current sampling circuit is specifically configured to: acquiring a current value output by the output end of the voltage transformation circuit according to a preset sampling period, and sending the current value to a control unit;
the control unit is further configured to: calculating the current change rate according to the sampling period, the current value obtained at present and the current value obtained at the previous time; and outputting the control signal when the current change rate is judged to be greater than or equal to a preset change rate threshold value.
Preferably, the control unit is further configured to: and calculating a target current value after a first time period according to the current value obtained currently and the calculated current change rate, and outputting the control signal when the target current value is greater than or equal to a preset second current threshold value.
Preferably, the magnitude of the second current threshold is equal to the magnitude of the first current threshold, and the magnitude of the first time period is equal to the magnitude of the sampling period.
Preferably, the current sampling circuit specifically includes:
the first resistor has a first end connected with the first end of the current-limiting resistor, a common end connected with the output end of the voltage transformation circuit, and a second end connected with the first end of the second resistor;
the second resistor with the second end grounded;
the first end of the third resistor is connected with the second end of the current-limiting resistor, and the second end of the third resistor is connected with the first end of the fourth resistor;
the fourth resistor with the second end grounded;
the first input end is connected with the second end of the first resistor, the second input end is connected with the second end of the third resistor, the output end is connected with the analog-to-digital conversion unit connected with the control unit, and the analog-to-digital conversion unit is used for obtaining voltage values sampled by the first end and the second end of the analog-to-digital conversion unit, and calculating a current value flowing through the current limiting resistor through the resistance values of the first resistor, the second resistor, the third resistor, the fourth resistor and the current limiting resistor to obtain a current value output by the output end of the voltage transformation circuit, and sending the current value to the control unit.
Preferably, the shunt circuit specifically includes:
the first end of the shunt resistor is connected with the input end of the APD tube core and serves as the first end of the shunt circuit, and the second end of the shunt resistor is connected with the first end of the switching device;
the control end is connected with the control unit, and is used as the control end of the shunt circuit, the second end is grounded, and the switching device used as the second end of the shunt circuit is used for conducting the first end and the second end of the switching device after receiving the control signal, so that the voltage applied to the APD tube core by the transformation circuit is reduced, and the current of the APD tube core is reduced.
Preferably, the switching device is a MOS transistor.
Preferably, the method further comprises the following steps:
and the display device is connected with the control unit and is used for displaying the current value currently received by the control unit in real time.
A protection method of an APD optical module comprises the following steps:
the current sampling circuit acquires a current value output by the output end of the voltage transformation circuit and sends the current value to the control unit;
the control unit outputs a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value;
the shunt circuit conducts the first end and the second end of the shunt circuit after receiving the control signal, and reduces the voltage applied to the APD tube core by the transformation circuit so as to reduce the current of the APD tube core.
An APD optical module comprising a protection circuit of any one of the above.
The technical scheme provided by the embodiment of the invention comprises the following steps: the current sampling circuit is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit; the control unit is connected with the current sampling circuit and used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value; the first end of the shunt circuit is connected with the input end of the APD tube core of the avalanche photodiode, the second end of the shunt circuit is grounded, the control end of the shunt circuit is connected with the control unit, the shunt circuit is used for conducting the first end and the second end of the shunt circuit after receiving a control signal, and the voltage of the transformation circuit acting on the APD tube core is reduced so as to reduce the current of the APD tube core.
In the scheme of the application, when the control unit determines that the current value received currently is greater than or equal to the preset first current threshold, it indicates that the current in the APD die is too high at this time, and the APD die may be damaged, and therefore, the control unit outputs the control signal. After the shunt circuit receives the control signal, the first end and the second end of the shunt circuit can be conducted, the voltage of the transformation circuit acting on the APD tube core is reduced after the shunt circuit is conducted, so that the gain of the APD tube core is reduced, and meanwhile, the current transformation circuit can play a role in shunting. Because the scheme of the application is irrelevant to the size of incident light, as long as the current value is detected to be overlarge, the current of the APD tube core is limited through the shunt circuit, so that the scheme of the application can effectively protect the damage of the APD tube core caused by the overcurrent.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a protection circuit of an APD optical module in the present invention;
fig. 2 is another schematic structural diagram of a protection circuit of an APD optical module in the present invention;
fig. 3 is a flowchart of an implementation method of the APD optical module according to the present invention.
Detailed Description
The core of the invention is to provide a protection circuit of an APD optical module, which can effectively protect an APD tube core from being damaged due to overcurrent.
In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a protection circuit of an APD optical module according to the present invention, where the protection circuit includes:
the current sampling circuit 10 is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit 20;
the sampling point of the current sampling circuit 10 is usually set between the output terminal of the transformer circuit and the input terminal of the APD die, and may be used to directly collect a current signal, or collect a voltage signal and convert the voltage signal into a corresponding current amount, without affecting the implementation of the present invention. It should be noted that, in the solution of the present application, the shunt circuit 30 is arranged in parallel with the APD die, and when the APD optical module normally operates, the shunt circuit 30 is not turned on, that is, is considered to be in an open circuit state, so that the current value output by the output end of the voltage transformation circuit, that is, the current value input to the APD die by the voltage transformation circuit, acquired by the current sampling circuit 10 at this time is obtained.
The voltage transformation circuit is usually a DC-DC boost circuit, and the specific boost amplitude can be set according to actual needs. In one specific embodiment shown in fig. 2, the current sampling circuit 10 specifically includes:
a first resistor R1, the first end of which is connected with the first end of the current limiting resistor R, the common end of which is connected with the output end of the transformation circuit, and the second end of which is connected with the first end of the second resistor R2;
a second resistor R2 with a second terminal grounded;
a third resistor R3, the first end of which is connected with the second end of the current limiting resistor R, and the second end of which is connected with the first end of the fourth resistor R4;
a fourth resistor R4 with its second terminal grounded;
the first input end is connected with the second end of the first resistor R1, the second input end is connected with the second end of the third resistor R3, and the output end is connected with the analog-to-digital conversion unit 11 of the control unit 20, which is used for obtaining the voltage values sampled by the first end and the second end of the analog-to-digital conversion unit, and calculating the current value flowing through the current limiting resistor R through the resistance value of the first resistor R1, the resistance value of the second resistor R2, the resistance value of the third resistor R3, the resistance value of the fourth resistor R4 and the resistance value of the current limiting resistor R, wherein the current value is used as the obtained current value output by the output end of the transformation circuit, and the current value is sent.
In this embodiment, considering that the APD optical module is usually provided with the current limiting resistor R connected in series with the APD die, the current value flowing through the current limiting resistor R, that is, the current value output by the output end of the transformer circuit, can be calculated by collecting the voltage of the current limiting resistor R. And considering that the voltage output by the transformer circuit is generally high, the scheme of the present application divides the voltage by using the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 to sample the signal of the analog-to-digital conversion unit 11.
The voltage of the first end collected by the analog-to-digital conversion unit 11 is a voltage U at a point CCWhich is connected to the voltage U at point AAThe conversion between can be expressed as:
correspondingly, voltage U at point DDAnd voltage U at point BBThe conversion between can be expressed as:
the calculated current value output by the output end of the voltage transformation circuit is IAPDCan be expressed as:
in addition, since the voltage is obtained by the analog-to-digital conversion unit 11 in this embodiment, the obtained ADC value needs to be obtained
And
converting into an actual voltage value, which can be specifically expressed as:
it should be noted that, depending on the analog-to-digital conversion unit 11, the parameters in the equation are different accordingly. For example, in a specific embodiment, the analog-to-digital conversion unit 11 is a 12-bit, dual-channel, low-power-consumption, successive approximation type analog-to-digital conversion unit, and the conversion time is fast, which is beneficial to timely and accurately determining the current value. The maximum value that the 12-bit analog-to-digital conversion unit 11 can output is 4095, and 3.3V is the reference voltage value corresponding to the maximum value.
In this embodiment, the resistance values of the resistors can be set and adjusted according to actual needs, for example, the resistance values are adjusted according to specific parameters of the APD die and the analog-to-digital conversion unit 11. For example, it is necessary to satisfy:
therein
For a set maximum current value, U, flowing into the APD diemaxThe maximum voltage value that can be input for the analog-to-digital conversion unit 11. The resistance of the limiting resistor R may typically be of the order of k Ω, for example 1k Ω. The first resistor R1 is usually much larger than the second resistor R2, and the third resistor R3 is usually much larger than the fourth resistor R4.
In addition, in this embodiment, the analog-to-digital conversion unit 11 determines the corresponding ADC value, and the analog-to-digital conversion unit 11 calculates the current value flowing through the current limiting resistor R based on the resistance values of the resistors, but in other embodiments, the analog-to-digital conversion unit 11 may be used only to determine the corresponding ADC value, and the related components for calculating the current value may be integrated with the control unit 20, or the control unit 20 may directly calculate the current value, without affecting the implementation of the present invention. For example, in one embodiment, the analog converter outputs the relevant ADC value via the SPI bus, and the current value is calculated after being received by a current calculating device integrated with the control unit 20.
And the control unit 20 is connected with the current sampling circuit 10 and is used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value.
The setting of a particular value for the first current threshold may be made as practical, for example, the first current threshold may be equal to or set slightly less than the maximum current value allowed for a particular APD die. When the current value obtained by the control unit 20 is greater than or equal to the preset first current threshold, it indicates that the APD die is at risk of being damaged, and the control unit 20 outputs a control signal.
It should be noted that, considering that when the current value received by the control unit 20 is equal to or greater than the first current threshold, a situation of manual misoperation or an extreme test situation may occur, and these extreme situations may not be eliminated in time, in an embodiment, the control unit 20 may continuously output the control signal when determining that the current value currently received is equal to or greater than the preset first current threshold, that is, the output of the control signal is not stopped no matter whether the subsequently received current value is reduced below the first current threshold, and the output of the control signal is stopped only when receiving a manually sent stop instruction. Of course, after the control signal is continuously output for a certain period of time, and it is determined that the received current value is equal to or less than the first current threshold again, the control signal may not be output. In addition, in some cases, considering that the duration of the APD abnormal condition may not be too long, the control signal may be output only when the current value is determined to be greater than or equal to the first current threshold, and the control signal may not be output any more as long as the received current value is reduced to be less than the first current threshold and the trigger conditions of other control signals are not met.
The shunt circuit 30 is used for conducting the first end and the second end of the shunt circuit after receiving a control signal, and reducing the voltage of the transformation circuit acting on the APD tube core so as to reduce the current of the APD tube core.
When the shunt circuit 30 does not receive the control signal, the first terminal and the second terminal of the shunt circuit are open. And when the control signal is received, the first terminal and the second terminal of the self are conducted. Because the first end of the shunt circuit 30 is connected to the input end of the APD die, and the second end is grounded, that is, the shunt circuit 30 is connected in parallel to the APD die, after the APD die is turned on, the bias voltage of the APD die can be reduced, that is, the voltage applied to the APD die by the transformer circuit is reduced. The gain of the APD die decreases as the bias voltage decreases. Meanwhile, the shunt circuit 30 is connected in parallel with the APD die, so that shunt of the APD die is realized, and the lower the impedance of the shunt circuit 30 is, the more obvious the shunt effect is. Therefore, the shunt circuit 30 provided in the present application can effectively reduce the current of the APD die after being turned on.
In an embodiment of the present invention, the shunt circuit 30 may specifically include:
a shunt resistor RH having a first end connected to the input end of the APD die as a first end of the shunt circuit 30 and a second end connected to the first end of the switching device Q1;
the control terminal is connected to the control unit 20, and serves as a control terminal of the shunt circuit 30, the second terminal is grounded, and the switching device Q1 serving as a second terminal of the shunt circuit 30 is configured to turn on the first terminal and the second terminal of the switching device after receiving the control signal, so as to reduce the voltage applied to the APD die by the transformer circuit, and reduce the current of the APD die.
Considering that the equivalent resistance of the APD die is typically in the order of several thousand ohms or more, the value of the shunt resistor RH may be typically several tens of ohms to several hundreds of ohms, so as to effectively reduce the bias voltage applied to the APD die to around 0 quickly and avoid excessive current of the shunt circuit 30 itself. The rapid reduction of current in the APD die is facilitated by the reduced bias voltage of the APD die while the current output by the voltage transformation circuit flows substantially through the shunt circuit 30 to ground.
The switching device Q1 can determine the on/off status of the first terminal and the second terminal according to whether the control signal is received. Considering the wide application of MOS transistors and the low cost, the switching device Q1 may be selected as a MOS transistor, and in the embodiment of fig. 2, the source of the MOS transistor is used as the second terminal of the switching device Q1, the drain of the MOS transistor is used as the first terminal of the switching device Q1, and the gate of the MOS transistor is used as the control terminal of the switching device Q1. Of course, in other embodiments, other types of the switching device Q1 may be selected according to actual needs, and the implementation of the present invention is not affected.
The protection circuit of the APD optical module provided by the embodiment of the invention comprises: the current sampling circuit is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit; the control unit is connected with the current sampling circuit and used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value; the first end of the shunt circuit is connected with the input end of the APD tube core of the avalanche photodiode, the second end of the shunt circuit is grounded, the control end of the shunt circuit is connected with the control unit, the shunt circuit is used for conducting the first end and the second end of the shunt circuit after receiving a control signal, and the voltage of the transformation circuit acting on the APD tube core is reduced so as to reduce the current of the APD tube core.
In the scheme of the application, when the control unit determines that the current value received currently is greater than or equal to the preset first current threshold, it indicates that the current in the APD die is too high at this time, and the APD die may be damaged, and therefore, the control unit outputs the control signal. After the shunt circuit receives the control signal, the first end and the second end of the shunt circuit can be conducted, the voltage of the transformation circuit acting on the APD tube core is reduced after the shunt circuit is conducted, so that the gain of the APD tube core is reduced, and meanwhile, the current transformation circuit can play a role in shunting. Because the scheme of the application is irrelevant to the size of incident light, as long as the current value is detected to be overlarge, the current of the APD tube core is limited through the shunt circuit, so that the scheme of the application can effectively protect the damage of the APD tube core caused by the overcurrent.
In an embodiment of the present invention, the current sampling circuit 10 is specifically configured to: acquiring a current value output by the output end of the voltage transformation circuit according to a preset sampling period, and transmitting the current value to the control unit 20;
the control unit 20 is further configured to: calculating the current change rate according to the sampling period, the current value obtained at present and the current value obtained at the previous time; and when the current change rate is judged to be larger than or equal to the preset change rate threshold value, outputting a control signal.
In such an embodiment, it is contemplated that if the shunt circuit 30 is controlled to conduct only when the current value is determined to be too large, damage to the APD die may still not be avoided in a timely manner in some cases. Therefore, in this embodiment, the current change rate is used as a precautionary measure. Specifically, the current sampling circuit 10 obtains a current value according to a preset sampling period, and the sampling period may be set to be shorter, so that the obtained current value is close to an instantaneous value, and the calculated current change rate may be more accurate, for example, the sampling period is set to be 1 microsecond.
The control unit 20 may subtract the current value obtained in the last sampling period from the current value obtained currently, and divide the current value by the sampling period to obtain the current change rate. When the current change rate is determined to be greater than or equal to the preset change rate threshold, the APD die is likely to have an abnormal condition, and the control unit 20 outputs a control signal to prevent in advance, so as to avoid the occurrence of a damage condition caused by an excessive APD current. In this embodiment, the control unit 20 uses the same sampling period as the current sampling period of the current value by the current sampling circuit 10 when calculating the current change rate, but in other embodiments, the control unit 20 may use other time intervals to calculate the current change rate, and the implementation of the present invention is not affected.
In one embodiment of the present invention, the control unit 20 is further configured to: and calculating a target current value after the first time period according to the current value obtained currently and the calculated current change rate, and outputting a control signal when the target current value is greater than or equal to a preset second current threshold value.
Considering that in practical applications, in some cases, the current value output by the output terminal of the transformer circuit is closer to the first current threshold, but the current only rises slowly, that is, the current change rate is lower than the change rate threshold, at this time, the control unit 20 may still need to output the control signal after detecting that the current value exceeds the first current threshold, and there is a certain risk of damaging the APD die. In this embodiment, the target current value after the first time period is calculated according to the current value obtained currently and the calculated current change rate, that is, the current at the future time is estimated, and when the target current value is greater than or equal to the preset second current threshold, the control unit 20 may output the control signal, which further avoids the damage to the APD die.
The first duration may be set to be generally short, for example, in one embodiment, the size of the first duration may be equal to the size of the sampling period used by the current sampling circuit 10. The magnitude of the second current threshold may also be set equal to the magnitude of the first current threshold for ease of design and calculation.
Referring to table 1, table 1 shows the test results of a plurality of APD optical modules according to this embodiment under a test environment at 25 ℃:
table 1:
according to the test result, even if the received incident light reaches 3dbm, the APD optical module applying the scheme of the application can still work normally and is not damaged.
In one embodiment of the present invention, the method further comprises:
and the display device is connected with the control unit 20 and is used for displaying the current value currently received by the control unit 20 in real time.
In this embodiment, the current value currently received by the control unit 20 is displayed in real time by using the display device, which is beneficial for the operator to know the current variation condition in the APD die, and especially is beneficial for the operator to perform subsequent processing during testing.
Corresponding to the above embodiments, the embodiments of the present invention further provide a protection method for an APD optical module, and the protection method for an APD optical module described below and the protection circuit for an APD optical module described above may be referred to in correspondence.
Referring to fig. 3, it is a flowchart of an implementation of a protection method for an APD optical module according to the present invention, where the method includes the following steps:
step S301: the current sampling circuit acquires a current value output by the output end of the voltage transformation circuit and sends the current value to the control unit;
step S302: the control unit outputs a control signal when judging that the current value received at present is greater than or equal to a preset first current threshold value;
step S303: the shunt circuit conducts the first end and the second end of the shunt circuit after receiving the control signal, and reduces the voltage applied to the APD tube core by the transformation circuit so as to reduce the current of the APD tube core.
In an embodiment of the present invention, step S301 specifically includes: the current sampling circuit acquires a current value output by the output end of the voltage transformation circuit according to a preset sampling period and sends the current value to the control unit;
further comprising the steps of: the control unit calculates the current change rate according to the sampling period, the current value obtained at present and the current value obtained at the previous time; and when the current change rate is judged to be larger than or equal to the preset change rate threshold value, outputting a control signal.
In one embodiment of the present invention, the method further comprises: and the control unit calculates a target current value after the first time period according to the current value obtained currently and the calculated current change rate, and outputs a control signal when the target current value is greater than or equal to a preset second current threshold value.
In an embodiment of the invention, the magnitude of the second current threshold is equal to the magnitude of the first current threshold, and the magnitude of the first time period is equal to the magnitude of the sampling period.
In one embodiment of the present invention, the method further comprises:
the display device displays the current value currently received by the control unit in real time.
The invention also discloses an APD optical module, which can include the protection circuit of the APD optical module in any embodiment, and the description is not repeated here.
It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The principle and the implementation of the present invention are explained in the present application by using specific examples, and the above description of the embodiments is only used to help understanding the technical solution and the core idea of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
Claims (8)
1. A protection circuit of an APD optical module, comprising:
the current sampling circuit is used for acquiring a current value output by the output end of the voltage transformation circuit and sending the current value to the control unit;
the control unit is connected with the current sampling circuit and used for outputting a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value;
the shunt circuit is used for conducting the first end and the second end of the shunt circuit after receiving the control signal, and reducing the voltage of the voltage transformation circuit acting on the APD tube core so as to reduce the current of the APD tube core;
the current sampling circuit is specifically configured to: acquiring a current value output by the output end of the voltage transformation circuit according to a preset sampling period, and sending the current value to a control unit;
the control unit is further configured to: calculating the current change rate according to the sampling period, the current value obtained at present and the current value obtained at the previous time; when the current change rate is judged to be larger than or equal to a preset change rate threshold value, outputting the control signal;
the control unit is further configured to: and calculating a target current value after a first time period according to the current value obtained currently and the calculated current change rate, and outputting the control signal when the target current value is greater than or equal to a preset second current threshold value.
2. The protection circuit of the APD optical module of claim 1, wherein the magnitude of the second current threshold is equal to the magnitude of the first current threshold, and the magnitude of the first duration is equal to the magnitude of the sampling period.
3. The protection circuit of the APD optical module of claim 1, wherein the current sampling circuit specifically comprises:
the first resistor has a first end connected with the first end of the current-limiting resistor, a common end connected with the output end of the voltage transformation circuit, and a second end connected with the first end of the second resistor;
the second resistor with the second end grounded;
the first end of the third resistor is connected with the second end of the current-limiting resistor, and the second end of the third resistor is connected with the first end of the fourth resistor;
the fourth resistor with the second end grounded;
the first input end is connected with the second end of the first resistor, the second input end is connected with the second end of the third resistor, the output end is connected with the analog-to-digital conversion unit connected with the control unit, and the analog-to-digital conversion unit is used for obtaining voltage values sampled by the first end and the second end of the analog-to-digital conversion unit, and calculating a current value flowing through the current limiting resistor through the resistance values of the first resistor, the second resistor, the third resistor, the fourth resistor and the current limiting resistor to obtain a current value output by the output end of the voltage transformation circuit, and sending the current value to the control unit.
4. The protection circuit of the APD optical module of claim 3, wherein the shunt circuit specifically comprises:
the first end of the shunt resistor is connected with the input end of the APD tube core and serves as the first end of the shunt circuit, and the second end of the shunt resistor is connected with the first end of the switching device;
the control end is connected with the control unit, and is used as the control end of the shunt circuit, the second end is grounded, and the switching device used as the second end of the shunt circuit is used for conducting the first end and the second end of the switching device after receiving the control signal, so that the voltage applied to the APD tube core by the transformation circuit is reduced, and the current of the APD tube core is reduced.
5. The protection circuit of the APD optical module of claim 4, wherein the switching device is a MOS transistor.
6. The protection circuit of the APD optical module according to any one of claims 1 to 5, further comprising:
and the display device is connected with the control unit and is used for displaying the current value currently received by the control unit in real time.
7. A method for protecting an APD optical module, comprising:
the current sampling circuit acquires a current value output by the output end of the voltage transformation circuit and sends the current value to the control unit;
the control unit outputs a control signal when judging that the current value received currently is greater than or equal to a preset first current threshold value;
the shunt circuit conducts the first end and the second end of the shunt circuit after receiving the control signal, and reduces the voltage of the voltage transformation circuit acting on the APD tube core so as to reduce the current of the APD tube core;
the current sampling circuit is specifically configured to: acquiring a current value output by the output end of the voltage transformation circuit according to a preset sampling period, and sending the current value to a control unit;
the control unit is further configured to: calculating the current change rate according to the sampling period, the current value obtained at present and the current value obtained at the previous time; when the current change rate is judged to be larger than or equal to a preset change rate threshold value, outputting the control signal;
the control unit is further configured to: and calculating a target current value after a first time period according to the current value obtained currently and the calculated current change rate, and outputting the control signal when the target current value is greater than or equal to a preset second current threshold value.
8. An APD optical module comprising the protection circuit of the APD optical module according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811320162.8A CN109217272B (en) | 2018-11-07 | 2018-11-07 | APD optical module and protection circuit and protection method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811320162.8A CN109217272B (en) | 2018-11-07 | 2018-11-07 | APD optical module and protection circuit and protection method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109217272A CN109217272A (en) | 2019-01-15 |
| CN109217272B true CN109217272B (en) | 2020-07-07 |
Family
ID=64995382
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811320162.8A Active CN109217272B (en) | 2018-11-07 | 2018-11-07 | APD optical module and protection circuit and protection method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109217272B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110767195B (en) * | 2019-11-20 | 2022-07-01 | 京东方科技集团股份有限公司 | Display device and driving method thereof |
| CN112260247A (en) * | 2020-12-23 | 2021-01-22 | 深圳市迅特通信技术有限公司 | APD protection circuit and device |
| CN114764170A (en) * | 2021-01-13 | 2022-07-19 | 青岛海信宽带多媒体技术有限公司 | Method and device with health record function and optical module |
| CN113253151B (en) * | 2021-06-16 | 2021-10-01 | 上海芯龙半导体技术股份有限公司 | Short circuit detection circuit, short circuit protection circuit and chip |
| CN116191381A (en) * | 2023-02-02 | 2023-05-30 | 武汉莱创德技术有限公司 | System and method for protecting APD corresponding to transient high light |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100512056C (en) * | 2004-12-17 | 2009-07-08 | 中兴通讯股份有限公司 | Optical receiving module with overload protection function |
| CN1945915A (en) * | 2006-10-26 | 2007-04-11 | 天津理工大学 | Lost super conductive fault current limiter fault detecting system based on DSP and its detecting method |
| TW200917191A (en) * | 2007-10-12 | 2009-04-16 | Nat Kaohsiung First University Of Science Technology | Driving unit for displaying apparatus with light emitting diode |
| CN102013676B (en) * | 2010-10-21 | 2014-05-14 | 成都优博创技术有限公司 | Protector and protection method of avalanche photodiode (APD) |
| CN105429096B (en) * | 2015-12-18 | 2018-05-15 | 华立科技股份有限公司 | A kind of ammeter over-current protection method and current foldback circuit |
| CN105552868B (en) * | 2016-01-29 | 2019-03-08 | 中国电子科技集团公司第二十三研究所 | Current foldback circuit and its control method based on constant current-supplying mode |
| CN107231199B (en) * | 2017-06-01 | 2019-08-06 | 上海市共进通信技术有限公司 | Optical module with overcurrent protection function |
-
2018
- 2018-11-07 CN CN201811320162.8A patent/CN109217272B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109217272A (en) | 2019-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109217272B (en) | APD optical module and protection circuit and protection method thereof | |
| US11243243B2 (en) | Circuit for arc detection in direct current and microprocessor | |
| EP2574938B1 (en) | Method for insulation fault monitoring with dynamic response qualities | |
| RU2422964C1 (en) | Device of electric circuits current protection against single-phase ground faults (versions) | |
| CN104092440A (en) | Photovoltaic system direct-current arc fault detection method, device, processor and system | |
| AT509251A1 (en) | 4 EXPERTS IN THE FIELD OF ARC FLASH IN PHOTOVOLTAIC PLANTS AND ONE SUCH PHOTOVOLTAIC PLANT | |
| KR102012420B1 (en) | DC arc breaking device including monitoring function | |
| CN111965533B (en) | Residual current calculation method, calculation device, storage medium and detection equipment | |
| CN104267273A (en) | Quick detection circuit and method for mains fluctuation | |
| EP2437225A1 (en) | Setting the operating mode of a danger warning system using an electrically readable two-pole in a danger warning socket, in particular a resistance | |
| CN106226585A (en) | Voltage monitor and electronic equipment monitoring device | |
| CN107396273B (en) | Detection circuit of broadcast sound box and detection method and device thereof | |
| CN109035839B (en) | Comprehensive monitoring method for electrical safety of traffic signal device | |
| AT13822U1 (en) | MONITORING DEVICE FOR AN ISOLATED NETWORK OF A PHOTOVOLTAIC PLANT | |
| US7148674B2 (en) | Apparatus for automatically measuring a relatively wide range of leakage currents | |
| CN104748842A (en) | Online detection method and system for arc sensor | |
| WO2014127960A1 (en) | Power measuring instrument with internal calibration of diode detectors | |
| CN108983065B (en) | Voltage amplifying circuit, detection circuit and circuit detection method thereof | |
| EP0411188A1 (en) | Method for supervising the operational state of an electro-optical transmission device, and circuitry for carrying out the method | |
| EP2847600B1 (en) | An apparatus and associated method for measuring a series resistance | |
| DE102017214102A1 (en) | Circuit and method for power off a B6 bridge circuit using the Generic Timer module in the microcontroller | |
| CN110646672A (en) | Converter power-on control circuit and method capable of being controlled in real time and converter equipment | |
| CN107918089B (en) | Circuit and method for partial discharge detection | |
| CN110850332A (en) | Trend statistical type grounding body monitoring method and device | |
| CN113176556B (en) | Laser energy detection circuit for laser radar equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |