阅读说明：本技术 一种高兼容性光功率采样监控电路及方法 (High-compatibility optical power sampling monitoring circuit and method ) 是由 魏兴 吴春付 王艳红 于 2020-04-23 设计创作，主要内容包括：本发明公开了一种高兼容性光功率采样监控电路及方法,电路包括控制器、驱动器、激光器、PNP管镜像电路、NPN管镜像电路、第一电阻、第二电阻、第三电阻、第四电阻、第五电阻和第六电阻；控制器与驱动器的第一端连接；驱动器的第二端通过第四电阻与激光器的第一端连接,驱动器的第四端通过第一电阻与PNP管镜像电路的第一端连接；PNP管镜像电路的第二端通过第五电阻与激光器的第三端连接；NPN管镜像电路的第一端通过第二电阻连接在驱动器与PNP管镜像电路之间,且通过第三电阻连接在PNP管镜像电路与激光器之间；NPN管镜像电路的第二端通过第六电阻与激光器的第三端连接。本发明实现了不同模式的电流采样解决方案,增加了产品兼容性,降低了开发成本。(The invention discloses a high-compatibility optical power sampling monitoring circuit and a method, wherein the circuit comprises a controller, a driver, a laser, a PNP tube mirror image circuit, an NPN tube mirror image circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; the controller is connected with the first end of the driver; the second end of the driver is connected with the first end of the laser through a fourth resistor, and the fourth end of the driver is connected with the first end of the PNP tube mirror image circuit through a first resistor; the second end of the PNP tube mirror image circuit is connected with the third end of the laser through a fifth resistor; the first end of the NPN tube mirror image circuit is connected between the driver and the PNP tube mirror image circuit through a second resistor, and is connected between the PNP tube mirror image circuit and the laser through a third resistor; and the second end of the NPN tube mirror image circuit is connected with the third end of the laser through a sixth resistor. The invention realizes current sampling solutions in different modes, increases product compatibility and reduces development cost.)

1. A high-compatibility optical power sampling monitoring circuit is characterized by comprising a controller, a driver, a laser, a PNP tube mirror image circuit, an NPN tube mirror image circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor;

the controller is connected with the first end of the driver;

the second end of the driver is connected with the first end of the laser through the fourth resistor, the third end of the driver is connected with the second end of the laser, and the fourth end of the driver is connected with the first end of the PNP tube mirror image circuit through the first resistor;

the second end of the PNP tube mirror image circuit is connected with the third end of the laser through the fifth resistor;

the first end of the NPN tube mirror image circuit is connected between the driver and the PNP tube mirror image circuit through the second resistor, and is connected between the PNP tube mirror image circuit and the laser through the third resistor; and the second end of the NPN tube mirror image circuit is connected with the third end of the laser through the sixth resistor.

2. The high-compatibility optical power sampling monitoring circuit according to claim 1, wherein the PNP transistor mirror circuit includes a first PNP transistor and a second PNP transistor;

the emitting electrode of the first PNP tube and the emitting electrode of the second PNP tube are connected in parallel and then are connected with the positive electrode of the power supply;

the collector and the base of the first PNP tube are respectively connected with the fifth resistor;

and the collector of the second PNP tube is connected with the second resistor, and the base of the second PNP tube is connected with the fifth resistor.

3. The optical power sampling monitor circuit of claim 2, wherein the first PNP transistor and the second PNP transistor have the same characteristics.

4. The high-compatibility optical power sampling monitoring circuit according to claim 2, wherein the NPN transistor mirror circuit includes a first NPN transistor and a second NPN transistor;

the emitter of the first NPN tube and the emitter of the second NPN tube are connected in parallel and then are connected with the negative voltage conversion circuit; the negative voltage conversion circuit is used for generating a negative power supply voltage;

a collector of the first NPN tube is connected with the third resistor, and a base of the first NPN tube is connected with the sixth resistor;

and the collector and the base of the second NPN tube are respectively connected with the sixth resistor.

5. The circuit of claim 4, wherein the first NPN transistor and the second NPN transistor have the same characteristics.

6. The high compatibility optical power sampling monitoring circuit of claim 1, wherein the driver comprises a laser diode and a photodiode;

one end of the photodiode is grounded, and the other end of the photodiode is connected with the fifth resistor and the sixth resistor respectively;

the cathode of the laser diode is connected between the photodiode and the ground, and the anode of the laser diode is connected with the driver.

7. The optical power sampling monitor circuit according to claim 1, wherein the controller and the driver are connected via an I2C bus.

8. The optical power sampling monitoring circuit according to claim 7, further comprising two pull-up resistors, a seventh resistor and an eighth resistor;

a first end of the seventh resistor is connected with a serial clock line in the I2C bus, and a second end of the seventh resistor is connected with a positive power supply voltage;

the eighth resistor has a first terminal connected to the serial data line in the I2C bus and a second terminal connected to a positive supply voltage.

9. A high-compatibility optical power sampling monitoring method implemented by using the high-compatibility optical power sampling monitoring circuit according to any one of claims 1 to 8, the method comprising:

judging whether a photodiode in the laser is grounded at an anode or a cathode, and judging whether the driver is in a Sink current sampling mode or a Source current sampling mode;

when the anode of the photodiode is grounded and the driver is in a Sink current sampling mode, the second resistor, the third resistor, the fourth resistor and the sixth resistor are disconnected, and the PNP tube mirror image circuit works to support the Sink current sampling mode of the driver;

when the anode of the photodiode is grounded and the driver is in a Source current sampling mode, the first resistor, the second resistor, the third resistor, the fifth resistor and the sixth resistor are disconnected, and the mPD is directly driven through the Source current sampling mode of the driver;

when the cathode of the photodiode is grounded and the driver is in a Source current sampling mode, the first resistor, the third resistor, the fourth resistor and the fifth resistor are disconnected, and the NPN tube mirror image circuit works to support the Source current sampling mode of the driver;

when the cathode of the photodiode is grounded and the driver is in a Sink current sampling mode, the second resistor, the fourth resistor and the fifth resistor are disconnected, and the NPN tube mirror image circuit works to support the Sink current sampling mode of the driver.

Technical Field

The invention relates to the technical field of optical fiber communication, in particular to a high-compatibility optical power sampling monitoring circuit and a method.

Background

A PD (Photo-Diode) is mainly used to monitor the emitted light Power in the Optical module, and implement an APC (Automatic Optical Power Control) function and a DDMI (Digital Diagnostic Monitoring Interface) for providing the emitted light Power, wherein the APC function is to maintain the emitted light Power stable by setting a target Monitoring current, and then dynamically adjust L D (L a laser Diode) bias current to Control the emitted light Power according to the sampled PD backlight current, so that the sampled current approaches the target Monitoring current, and the emitted light Power Monitoring is to read the ADC value of the driver chip (driver) through an IIC (Inter-Integrated Circuit, Integrated Circuit bus) via an MCU (Micro controller unit, single chip), and then update and store the ADC value in a corresponding protocol area in real time after the MCU is converted.

Currently, in optical module applications, in the first aspect, the pin definitions of PDs are not completely the same for different device manufacturers. The common connection mode has two types, wherein one type is that the PD anode is connected with GND, and the other type is that the PD cathode is connected with GND. Different circuit designs are required for driving, so that repeated board beating is caused, and the product development cost is greatly increased. In the second aspect, although most of the driver chips provided by manufacturers support two current sampling modes, namely Sink and Source, a small number of the driver chips of manufacturers only support the Sink current sampling mode, and the conventional design is that the optical power monitoring is realized by sampling the voltage of an ADC, which cannot realize the APC function to control the optical power.

In view of the above, a high compatibility circuit is needed to solve the drawbacks of the prior art.

Disclosure of Invention

The invention provides a high-compatibility optical power sampling monitoring circuit and a method thereof, which are used for solving the defects of the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

in a first aspect, an embodiment of the present invention provides a high-compatibility optical power sampling monitoring circuit, including a controller, a driver, a laser, a PNP transistor mirror circuit, an NPN transistor mirror circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor;

the controller is connected with the first end of the driver;

the second end of the driver is connected with the first end of the laser through the fourth resistor, the third end of the driver is connected with the second end of the laser, and the fourth end of the driver is connected with the first end of the PNP tube mirror image circuit through the first resistor;

the second end of the PNP tube mirror image circuit is connected with the third end of the laser through the fifth resistor;

the first end of the NPN tube mirror image circuit is connected between the driver and the PNP tube mirror image circuit through the second resistor, and is connected between the PNP tube mirror image circuit and the laser through the third resistor; and the second end of the NPN tube mirror image circuit is connected with the third end of the laser through the sixth resistor.

Further, in the high-compatibility optical power sampling monitoring circuit, the PNP transistor mirror circuit includes a first PNP transistor and a second PNP transistor;

the emitting electrode of the first PNP tube and the emitting electrode of the second PNP tube are connected in parallel and then are connected with the positive electrode of the power supply;

the collector and the base of the first PNP tube are respectively connected with the fifth resistor;

and the collector of the second PNP tube is connected with the second resistor, and the base of the second PNP tube is connected with the fifth resistor.

Further, in the high-compatibility optical power sampling monitoring circuit, the characteristics of the first PNP transistor and the second PNP transistor are consistent.

Further, in the high-compatibility optical power sampling monitoring circuit, the NPN transistor mirror circuit includes a first NPN transistor and a second NPN transistor;

the emitter of the first NPN tube and the emitter of the second NPN tube are connected in parallel and then are connected with the negative voltage conversion circuit; the negative voltage conversion circuit is used for generating a negative power supply voltage;

a collector of the first NPN tube is connected with the third resistor, and a base of the first NPN tube is connected with the sixth resistor;

and the collector and the base of the second NPN tube are respectively connected with the sixth resistor.

Further, in the high-compatibility optical power sampling monitoring circuit, the characteristics of the first NPN tube and the second NPN tube are consistent.

Further, in the high-compatibility optical power sampling monitoring circuit, the driver comprises a laser diode and a photodiode;

one end of the photodiode is grounded, and the other end of the photodiode is connected with the fifth resistor and the sixth resistor respectively;

the cathode of the laser diode is connected between the photodiode and the ground, and the anode of the laser diode is connected with the driver.

Further, in the high-compatibility optical power sampling monitoring circuit, the controller and the driver are connected through an I2C bus.

Furthermore, the high-compatibility optical power sampling monitoring circuit further comprises two pull-up resistors, namely a seventh resistor and an eighth resistor;

a first end of the seventh resistor is connected with a serial clock line in the I2C bus, and a second end of the seventh resistor is connected with a positive power supply voltage;

the eighth resistor has a first terminal connected to the serial data line in the I2C bus and a second terminal connected to a positive supply voltage.

In a second aspect, an embodiment of the present invention provides a high-compatibility optical power sampling monitoring method, which is implemented by using the high-compatibility optical power sampling monitoring circuit according to the first aspect, and the method includes:

judging whether a photodiode in the laser is grounded at an anode or a cathode, and judging whether the driver is in a Sink current sampling mode or a Source current sampling mode;

when the anode of the photodiode is grounded and the driver is in a Sink current sampling mode, the second resistor, the third resistor, the fourth resistor and the sixth resistor are disconnected, and the PNP tube mirror image circuit works to support the Sink current sampling mode of the driver;

when the anode of the photodiode is grounded and the driver is in a Source current sampling mode, the first resistor, the second resistor, the third resistor, the fifth resistor and the sixth resistor are disconnected, and the mPD is directly driven through the Source current sampling mode of the driver;

when the cathode of the photodiode is grounded and the driver is in a Source current sampling mode, the first resistor, the third resistor, the fourth resistor and the fifth resistor are disconnected, and the NPN tube mirror image circuit works to support the Source current sampling mode of the driver;

when the cathode of the photodiode is grounded and the driver is in a Sink current sampling mode, the second resistor, the fourth resistor and the fifth resistor are disconnected, and the NPN tube mirror image circuit works to support the Sink current sampling mode of the driver.

The high-compatibility optical power sampling monitoring circuit and the method provided by the embodiment of the invention have the advantages that the circuit design structure is simple, different pin modes of the laser and the function collocation of the driver are considered, current sampling solutions of different modes are realized, repeated board beating is not needed, the compatibility of a product development platform is increased, and the product development cost is reduced.

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, and 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 these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a high-compatibility optical power sampling monitoring circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a high-compatibility optical power sampling monitoring circuit according to an embodiment of the present invention;

fig. 3 is a schematic flowchart of a high-compatibility optical power sampling monitoring method according to an embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

In the description of the present invention, it is to be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Furthermore, the terms "long", "short", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention, but do not indicate or imply that the referred devices or elements must have the specific orientations, be configured to operate in the specific orientations, and thus are not to be construed as limitations of the present invention.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.