Control circuit

Abstract

The utility model discloses a control circuit, and the circuit comprises an input end which is connected with a power supply part and is used for providing electric energy; the output end is connected with an electric part; the enabling end is used for controlling connection and disconnection of a line between the input end and the output end; the first switch is respectively connected with the input end and the enabling end and is used for receiving a level signal of the enabling end so as to enable the enabling end to be switched on or switched off; and the second switch is connected with the first switch and is used for receiving a level signal of the first switch so as to switch on or switch off the first switch, thereby controlling the on-off of a line between the input end and the output end. According to the invention, by controlling the on-off state of the triode, accurate control of product output can be realized under different enable end input conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to a control circuit. BACKGROUND

[0002] Radiation resistant DC / DC converters are devices used to provide power stably in a radiation environment. Such converters need to be able to withstand high doses of ionizing radiation while maintaining the normal operation of the circuit. In some applications, such as aerospace, military and nuclear industry, the enable terminal of the DC / DC converter needs to be compatible with TTL (Transistor-Transistor Logic) level in order to receive control signals from TTL logic circuits. Conventional DC / DC converter enable terminals are not directly compatible with TTL level input because their logic level does not match TTL level. SUMMARY

[0003] The purpose of the embodiment of the present application is to provide a control circuit, comprising:

[0004] an input terminal connected with a power supply for providing electric energy;

[0005] an output terminal connected with a power consumer;

[0006] an enable terminal for controlling the on-off of a line between the input terminal and the output terminal;

[0007] a first switch connected with the input terminal and the enable terminal respectively for accepting a level signal of the enable terminal to make it conduct or cut off;

[0008] a second switch connected with the first switch for accepting a level signal of the first switch to make it conduct or cut off, thereby controlling the on-off of the line between the input terminal and the output terminal.

[0009] As an optional embodiment, the first switch is a triode, the base of the first switch is connected with the enable terminal through a second resistor, the emitter of the first switch is connected with the input terminal through a first resistor, and the collector of the first switch is grounded.

[0010] As an optional embodiment, one end of the first resistor is connected with one end of a second diode, the other end of the second diode is connected with one end of a first diode, and the other end of the first diode is grounded.

[0011] As an optional embodiment, the second switch is a triode, the base of the second switch is connected with the collector of the first switch through a third resistor, the emitter of the second switch is grounded, and the collector of the second switch is connected with the output terminal.

[0012] As an optional embodiment, a first capacitor and a fourth resistor are further connected in parallel between the collector of the first switch and the third resistor, and the first capacitor and the fourth resistor are both grounded.

[0013] As an optional embodiment, a third diode is connected between the collector of the second switch and the output terminal.

[0014] The beneficial effects of the embodiments of the present application are as follows:

[0015] The control circuit of the present application can directly compatible with TTL level input, and control the on-off of the control circuit, that is, it can be seamlessly integrated with the existing TTL logic circuit without additional level conversion circuit, thereby simplifying the system design and reducing the cost.

[0016] The present application can realize precise control of product output under different enable end input conditions by controlling the switching state of the triode, is flexible to use, and the product can adapt to different working modes and application scenarios.

[0017] And allows users to replace different voltage stabilizing tubes according to different TTL high level voltages, so that the circuit can adapt to the needs of different customers, and enhances the market competitiveness of the product. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The circuit diagram of the embodiments of the present application.

[0019] Among them,

[0020] VIN, input terminal; VCC, output terminal; INH, enable terminal; Q1, first switch; Q2, second switch; D1, first diode; D2, second diode; D3, third diode; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; C1, first capacitor. DETAILED DESCRIPTION

[0021] The various schemes and features of the present application are described herein with reference to the accompanying drawings.

[0022] It should be understood that various modifications can be made to the embodiments of the present application. Therefore, the above description should not be regarded as limiting, but only as an example of the embodiments. Those skilled in the art will think of other modifications within the scope and spirit of the present application.

[0023] The accompanying drawings included in the specification and forming a part thereof illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0024] These and other characteristics of the present application will become patently apparent as the description proceeds in conjunction with the accompanying drawings, by way of non-limiting examples.

[0025] It should also be understood that, while the present application has been described above with reference to particular means, materials and embodiments, the application is not limited to the particulars described and as many modifications can be made by those skilled in the art without departing from the spirit and scope of the application.

[0026] The above and other aspects, features and advantages of the present application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of non-limiting examples various embodiments of the application.

[0027] Specific embodiments of the present application are described hereinafter with reference to the drawings; however, it will be understood that the application is not limited to the embodiments described, but that they can be implemented in many ways. Well-known and / or redundant functions and structures are not described in detail to avoid obscuring the application unnecessarily. Therefore, specific structural and functional details disclosed herein are not intended to limit the scope of the claims but merely serve as examples of representative structures and / or methods consistent with the application.

[0028] The specification can use phrases such as "in one embodiment", "in another embodiment", "in yet another embodiment", or "in other embodiments", which can refer to one or more of the same or different embodiments of the application.

[0029] A control circuit of an embodiment of the present application, as shown in Figure 1 includes an input terminal VIN, an output terminal VCC, an enable terminal INH, a first switch Q1, and a second switch Q2. The first switch Q1 is a PNP transistor, and the second switch Q2 is an NPN transistor.

[0030] The input terminal VIN is connected to a power supply for providing power. The output terminal VCC is connected to a load for providing a stable operating voltage. The enable terminal INH is connected to a TTL logic circuit for controlling the on-off of the line between the input terminal VIN and the output terminal VCC.

[0031] The first switch Q1 is connected to the input terminal VIN and the enable terminal INH, respectively, for accepting the level signal of the enable terminal INH to make it conduct or cut off. A high level makes the first switch Q1 cut off, and a low level makes the first switch Q1 conduct.

[0032] The second switch Q2 is connected with the first switch Q1, and is used to accept the level signal of the first switch Q1 to make it conduct or cut off, so as to control the on-off of the circuit between the input end VIN and the output end VCC. High level makes the second switch Q2 conduct, and low level makes the second switch Q2 cut off.

[0033] The first switch Q1 is a PNP triode, the base of the first switch Q1 is connected with the enable end INH through the second resistor R2, the emitter of the first switch Q1 is connected with the input end VIN through the first resistor R1, and the collector of the first switch Q1 is grounded.

[0034] One end of the first resistor R1 is connected with one end of the second diode D2, the other end of the second diode D2 is connected with one end of the first diode D1, and the other end of the first diode D1 is grounded.

[0035] Specifically, when the base of the first switch Q1 receives high level, the first switch Q1 conducts. The second resistor R2 is used to limit the current flowing through the base of the first switch Q1, so as to protect the first switch Q1 from being damaged by excessive base current. The first resistor R1 is used to limit the current flowing through the first diode D1, so as to protect the first diode D1 from being damaged by excessive current.

[0036] The first diode D1 is a voltage stabilizing diode, which is used for voltage stabilization to ensure that the emitter voltage of the first switch Q1 does not exceed the maximum allowable value. Its voltage stabilization value is lower than the high level of TTL to ensure that the first switch Q1 can normally cut off.

[0037] When the first switch Q1 conducts, the second diode D2 provides a loop for the collector current of the first switch Q1, so as to prevent the first switch Q1 from being damaged due to sudden interruption of current.

[0038] The second switch Q2 is an NPN triode, the base of the second switch Q2 is connected with the collector of the first switch Q1 through the third resistor R3, the emitter of the second switch Q2 is grounded, and the collector of the second switch Q2 is connected with the output end VCC.

[0039] The first capacitor C1 and the fourth resistor R4 are connected in parallel between the collector of the first switch Q1 and the third resistor R3, and both the first capacitor C1 and the fourth resistor R4 are grounded.

[0040] Specifically, the third resistor R3 and the fourth resistor R4 are both used to limit the current flowing through the base of the second switch Q2, and the first capacitor C1 is used to smooth the current fluctuation when the first switch Q1 conducts, so as to reduce voltage spikes.

[0041] The third diode D3 is arranged between the collector of the second switch Q2 and the output terminal VCC.

[0042] Specifically, the third diode D3 is arranged to provide a current loop for the input terminal VIN when the second switch Q2 is turned on, so that the input terminal VIN cannot normally supply power to the output terminal VCC, and prevent the second switch Q3 from being damaged by the reverse current generated by the abnormality.

[0043] In summary, the working principle of the control circuit is as follows:

[0044] When the enable terminal INH inputs a TTL high level or is left floating, the first switch Q1 (PNP transistor) is turned off because the high level turns off the first switch Q1. At this time, the base of the first switch Q1 receives a high level signal through the second resistor R2, the emitter is connected with the input terminal VIN through the first resistor R1, and the collector is grounded.

[0045] Since the first switch Q1 is turned off, no current flows from the collector of the first switch Q1 to the base of the second switch Q2 (NPN transistor) through the third resistor R3, and the second switch Q2 is also turned off. The base of the second switch Q2 is connected with the collector of the first switch Q1 through the third resistor R3, the emitter is grounded, and the collector is connected with the output terminal VCC.

[0046] The input terminal VIN can normally supply power to the output terminal VCC, and the load works normally.

[0047] ② When the enable terminal INH inputs a TTL low level or is grounded, the first switch Q1 is turned on, and the low level turns on the first switch Q1. At this time, the base of the first switch Q1 receives a low level signal. The second resistor R2 limits the current flowing through the base of the first switch Q1, protecting the first switch Q1. The first resistor R1 limits the current flowing through the first diode D1, protecting the first diode D1. The first diode D1 is a voltage stabilizing diode, which ensures that the emitter voltage of the first switch Q1 does not exceed the maximum allowed value, and its voltage stabilizing value is lower than the TTL high level, ensuring that the first switch Q1 can be normally turned off. When the first switch Q1 is turned on, the second diode D2 provides a collector current loop to prevent the first switch Q1 from being damaged due to current interruption.

[0048] After the first switch Q1 is turned on, current flows from the collector of the first switch Q1 to the base of the second switch Q2 through the third resistor R3, turning on the second switch Q2. The third resistor R3 and the fourth resistor R4 limit the current flowing through the base of the second switch Q2, and the first capacitor C1 smoothens the current fluctuation when the first switch Q1 is turned on, reducing voltage spikes.

[0049] When the second switch Q2 is turned on, the third diode D3 provides a current loop, the input end VIN cannot normally supply power to the output end VCC, and the electrical component cannot normally work, and abnormal reverse current is prevented from damaging the output end VCC.

[0050] The above examples are only exemplary embodiments of the present application and are not intended to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements are also considered to fall within the protection scope of the present application.

Claims

1. A control circuit, characterized in that, include: The input terminal connects to the power supply unit to provide electrical energy; The output terminal connects to the electrical component. The enable terminal is used to control the connection or disconnection of the line between the input terminal and the output terminal; A first switch is connected to the input terminal and the enable terminal respectively, and is used to receive the level signal of the enable terminal to turn it on or off. The second switch, connected to the first switch, is used to receive the level signal from the first switch to turn it on or off, thereby controlling the connection or disconnection of the line between the input terminal and the output terminal.

2. The control circuit as described in claim 1, characterized in that, The first switch is a transistor. The base of the first switch is connected to the enable terminal through a second resistor, the emitter is connected to the input terminal through a first resistor, and the collector is grounded.

3. The control circuit as described in claim 2, characterized in that, One end of the first resistor is connected to one end of the second diode, the other end of the second diode is connected to one end of the first diode, and the other end of the first diode is grounded.

4. The control circuit as described in claim 1, characterized in that, The second switch is a transistor. The base of the second switch is connected to the collector of the first switch through a third resistor. Its emitter is grounded, and its collector is connected to the output terminal.

5. The control circuit as described in claim 1, characterized in that, A first capacitor and a fourth resistor are connected in parallel between the collector of the first switch and the third resistor, and both the first capacitor and the fourth resistor are grounded.

6. The control circuit as described in claim 1, characterized in that, A third diode is provided between the collector of the second switch and the output terminal.

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