阅读说明：本技术 一种自适应背光的apc控制电路 (APC control circuit that self-adaptation is shaded ) 是由 李培军 田军 高南京 于 2020-12-16 设计创作，主要内容包括：本发明提供了一种自适应背光的APC控制电路,包括开关电路(101)、MCU(103)和APC电路(102)；MCU(103)的一端通过开关电路(101)连接背光采样电路(200),另一端连接APC电路(102)；MCU(103)用于在判断得到输入MCU(103)的背光采样值大于预设的上限阈值时,控制开关电路(101)断开,同时将APC电路(102)设置为开环,且开环静态工作点预先设置,以使光模块正常工作。本发明能够很好的解决当背光检测电路本身异常时间接造成的模块bias状态异常,同时还能避免背光电路短路时伴随的大电流给SFP+光模块甚至客户设备带来损伤。相当于给APC电路增设一道“防火墙”。(The invention provides an APC control circuit of self-adaptive backlight, which comprises a switch circuit (101), an MCU (103) and an APC circuit (102); one end of the MCU (103) is connected with the backlight sampling circuit (200) through the switch circuit (101), and the other end is connected with the APC circuit (102); the MCU (103) is used for controlling the switch circuit (101) to be switched off when the backlight sampling value input to the MCU (103) is judged to be larger than the preset upper limit threshold value, and meanwhile, the APC circuit (102) is set to be an open loop, and the static working point of the open loop is preset so that the optical module can normally work. The invention can well solve the abnormal state of the module bias indirectly caused when the backlight detection circuit is abnormal, and simultaneously can avoid the damage of the large current accompanied by the short circuit of the backlight circuit to the SFP + optical module and even the client equipment. It is equivalent to add a firewall to the APC circuit.)

1. An APC control circuit of an adaptive backlight, characterized by comprising a switch circuit (101), an MCU (103), and an APC circuit (102); one end of the MCU (103) is connected with the backlight sampling circuit (200) through the switch circuit (101), and the other end of the MCU is connected with the APC circuit (102);

the MCU (103) is used for controlling the switch circuit (101) to be switched off when the backlight sampling value input into the MCU (103) is judged to be larger than a preset upper limit threshold value, and meanwhile, the APC circuit (102) is set to be an open loop, and a static working point of the open loop is preset so that the optical module can normally work; the APC circuit (102) is used for controlling the bias current bias loaded to the light emitting component to output the target light power.

2. The APC control circuit of an adaptive backlight according to claim 1, wherein an upper threshold value and a lower threshold value of a backlight sampling value are preset in the MCU (103); accordingly, the method can be used for solving the problems that,

and the MCU (103) is also used for setting the APC circuit (102) to be open loop when the backlight sampling value input to the MCU (103) is judged to be smaller than the lower limit threshold, and the static working point of the open loop is preset so as to enable the optical module to normally work.

3. The APC control circuit according to claim 1, wherein the signal output terminal of the backlight sampling circuit (200) is connected with the input terminal of the switch circuit (101), the output terminal of the switch circuit (101) is connected with the ADC interface of the MCU (103), and the MCU (102) is connected with the APC circuit (102) through IIC.

4. An APC control circuit of self-adaptive backlight is characterized by comprising an MCU (104) with an IO port capable of being internally switched and an APC circuit (102); the signal output end of the backlight sampling circuit (200) is connected with the input end of the MCU (104) with the internal switch IO port, and the MCU (104) with the internal switch IO port is connected with the APC circuit (102) through the IIC.

Technical Field

The invention relates to the technical field of optical communication, in particular to an APC control circuit of self-adaptive backlight.

Background

Currently, in the existing SFP + optical module, the APC control circuit is divided into an open loop and a closed loop. Most SFP + optical modules adopt closed-loop control on the emitted light power, namely a target light power value is given, the MCU calculates a current light power value through the detected backlight current, then the current light power value is compared with the target light power value, and finally the bias current bias output is adjusted according to the comparison result, so that the aim of stabilizing the light power is achieved.

Whether the light module bias can be in the normal working range is determined by whether the APC can accurately detect the backlight current under the closed-loop control state. When the backlight detection circuit itself is abnormal, the operation mode of the APC closed-loop control may instead cause the bias current bias of the module to be adjusted to an abnormal state.

Disclosure of Invention

To solve the above problems, embodiments of the present invention provide an APC control circuit and system for an adaptive backlight that overcomes or at least partially solves the above problems.

In a first aspect, an embodiment of the present invention provides an APC control circuit for adaptive backlight, including a switch circuit, an MCU and an APC circuit; one end of the MCU is connected with the backlight sampling circuit through a switch circuit, and the other end of the MCU is connected with the APC circuit;

the MCU is used for controlling the switch circuit to be switched off when the backlight sampling value input to the MCU is judged to be larger than a preset upper limit threshold value, and meanwhile, the APC circuit is set to be open-loop, and the static working point of the open-loop is preset so that the optical module works normally; the APC circuit is used for controlling the bias current bias loaded to the light emitting component to output the target light power.

The MCU is preset with an upper threshold and a lower threshold of a backlight sampling value; accordingly, the method can be used for solving the problems that,

and the MCU is also used for setting the APC circuit to be open loop when the backlight sampling value input to the MCU is judged to be smaller than the lower limit threshold value, and the open loop static working point is preset so as to enable the optical module to normally work.

The signal output end of the backlight sampling circuit is connected with the input end of the switch circuit, the output end of the switch circuit is connected with the ADC interface of the MCU, and the MCU is connected with the APC circuit through the IIC.

In a second aspect, an embodiment of the present invention provides another APC control circuit for adaptive backlight, including an MCU with an IO port capable of being internally switched and an APC circuit; the signal output end of the backlight sampling circuit is connected with the input end of the MCU with the internal switch IO port, and the MCU with the internal switch IO port is connected with the APC circuit through the IIC.

According to the APC control circuit of the self-adaptive backlight provided by the embodiment of the invention, the backlight sampling value judgment function is added in the MCU, and the switch circuit is added, or after the MCU has an internal IO switch function, even if the backlight sampling circuit is short-circuited or disconnected, the SFP + optical module can normally work, and the communication service is not influenced. The abnormal state of the module bias caused by the abnormal backlight detection circuit is solved, and the damage of the SFP + optical module and even client equipment caused by the large current accompanying the short circuit of the backlight circuit can be avoided.

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 introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an APC control circuit for adaptive backlight according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an APC control circuit for adaptive backlight according to another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present 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.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Currently, in the existing SFP + optical module, the APC circuit is divided into an open loop and a closed loop. Most SFP + optical modules adopt closed-loop control on the emitted light power, namely a target light power value is given, the MCU calculates a current light power value through the detected backlight current, then the current light power value is compared with the target light power value, and finally the bias current bias output is adjusted according to the comparison result, so that the aim of stabilizing the light power is achieved. Whether the bias current bias of the optical module can be in a normal working range is determined by whether the APC circuit can accurately detect the backlight current in a closed-loop control state. When the backlight detection circuit itself is abnormal, the operation mode of the APC closed-loop control may instead cause the bias current bias of the module to be adjusted to an abnormal state.

To solve the problem, an embodiment of the present invention provides an APC control circuit for adaptive backlight, which can well solve the abnormal status of a module bias indirectly caused by an abnormal backlight detection circuit, and meanwhile, can prevent a large current accompanying a short circuit of a backlight circuit from damaging an SFP + optical module and even a client device. It is equivalent to add a firewall to the APC circuit. The following description and description of various embodiments are presented in conjunction with the following drawings.

Fig. 1 is a schematic structural diagram of an APC Control circuit for adaptive backlight according to an embodiment of the present invention, as shown in fig. 1, the APC Control circuit for adaptive backlight includes a switch circuit 101, an MCU (micro controller Unit) 103, and an APC (Automatic Power Control) circuit 102; one end of the MCU103 is connected with the backlight sampling circuit 200 through the switch circuit 101, and the other end is connected with the APC circuit 102;

the MCU103 is used for controlling the switch circuit 101 to be switched off when the backlight sampling value input to the MCU103 is judged to be larger than a preset upper limit threshold value, and meanwhile, the APC circuit 102 is set to be an open loop so as to enable the optical module to normally work; the APC circuit 102 is used to control the bias current bias applied to the light emitting element to output a target optical power.

Specifically, a signal output end of the backlight sampling Circuit 200 is connected to an input end of the switch Circuit 101, an output end of the switch Circuit 101 is connected to an ADC (Analog to Digital Converter) interface of the MCU 102, and the MCU 102 is connected to the APC Circuit 102 through an IIC (Inter-Integrated Circuit bus).

In fig. 1, the switch circuit 101 is used to isolate a PD (Photo-Diode) sampling current or voltage signal from the MCU, and when the backlight sampling value detected by the MCU is normal, the switch circuit is normally turned on, and the input and output are equal or proportional to each other. When the backlight sampling value detected by the MCU is abnormal, the MCU controls the switch circuit to be disconnected. And judging whether the backlight sampling value is normal or not by the MCU. The backlight sampling value herein refers to a sampling value of the backlight current.

In this embodiment, an upper threshold and a lower threshold of the backlight sampling value are set in advance for the MCU. The MCU judges whether the input backlight sampling value is normal or not and takes different operations according to the judgment result. It can be understood that, in this embodiment, the upper threshold and the lower threshold of the backlight sampling value may be set according to actual situations.

When the backlight sampling value input to the MCU is smaller than the preset lower threshold, the sampling circuit may be open or the PD may be abnormal. At this time, the MCU sets the APC circuit 102 to an open loop, and the open loop static operating point is also set in advance, so that the optical module can still operate normally. The optical module herein may be an SFP + optical module.

When the backlight sampling value input to the MCU is larger than the preset upper limit threshold value, the sampling circuit may be short-circuited at the moment, and if the sampling circuit is not cut off in time, the large current may endanger other circuits and equipment. At this time, the MCU controls the switch circuit 101 to be turned off, and the APC circuit 102 is set to be open loop, and the open loop static operating point is also set in advance, so that the module can still operate normally without affecting the communication service.

When the backlight sampling value detected by the MCU is in the middle of the upper limit and the lower limit, namely in the normal range, the MCU normally calculates and reports the light power, and the APC circuit still continues to work in a closed loop. The current light power value is calculated by the MCU according to the detected backlight current, then compared with the target light power value, and finally the bias current bias output is adjusted according to the comparison result, thereby achieving the purpose of stabilizing the light power.

It should be noted that, in the conventional APC circuit, the sampled backlight current or voltage is directly compared with a set target value, and then the working current of the SFP + optical module is increased or decreased to reach the target optical power value. However, when the backlight sampling circuit is short-circuited or short-circuited, the conventional APC loop does not make a determination, but directly increases or decreases the operating current of the SFP + optical module, so that the SFP + optical module originally at a normal operating point is abnormally operated, thereby affecting communication services. In the APC control circuit for adaptive backlight according to the embodiments of the present invention, a function of determining a backlight sampling value is added to the MCU, and after the switching circuit is added, even if the backlight sampling circuit is short-circuited or open-circuited, the SFP + optical module can normally operate without affecting communication services. According to the APC control circuit of the self-adaptive backlight provided by the embodiment of the invention, the backlight sampling value judgment function is added in the MCU, and the switch circuit is added, or after the MCU has an internal IO switch function, even if the backlight sampling circuit is short-circuited or disconnected, the SFP + optical module can normally work, and the communication service is not influenced. The abnormal state of the module bias caused by the abnormal backlight detection circuit is solved, and the damage of the SFP + optical module and even client equipment caused by the large current accompanying the short circuit of the backlight circuit can be avoided.

In an embodiment, fig. 2 is a schematic structural diagram of an APC control circuit for adaptive backlight according to another embodiment of the present invention, as shown in fig. 2, based on the content of the foregoing embodiment, an APC control circuit for adaptive backlight according to another embodiment of the present invention includes an MCU104 with an IO port capable of being internally switched and an APC circuit 102; the signal output end of the backlight sampling circuit 200 is connected with the input end of the MCU104 with the internal switchable IO port, and the MCU104 with the internal switchable IO port is connected with the APC circuit 102 through the IIC. The "MCU with IO switch" in fig. 2 is the MCU104 with an IO port capable of internal switching in this embodiment.

In the APC control circuit for adaptive backlight in fig. 2, only the switch circuit 101 and the MCU103 in fig. 1 are replaced with the MCU104 capable of switching the IO port internally. The technical concept and operation principle of the APC control circuit for adaptive backlight in fig. 2 are the same as those of the APC control circuit for adaptive backlight in fig. 1, and the detailed description of the present embodiment is omitted here.

In summary, the present invention provides an APC control circuit for adaptive backlight, in which a backlight sampling value determining function is added in an MCU, and a switch circuit is added, or after the MCU has an internal IO switch function, even if the backlight sampling circuit itself is short-circuited or open-circuited, an SFP + optical module can also work normally without affecting communication services. The abnormal state of the module bias caused by the abnormal backlight detection circuit is solved, and the damage of the SFP + optical module and even client equipment caused by the large current accompanying the short circuit of the backlight circuit can be avoided.

The embodiments of the present invention can be arbitrarily combined to achieve different technical effects.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.