Wake-up circuit for MCU

Abstract

The utility model discloses a wake-up circuit used for an MCU. The wake-up circuit comprises a first wake-up sub-circuit and a second wake-up sub-circuit. The input end of the first wake-up sub-circuit is connected with a first signal output end (X1) of the whole vehicle, and the output end of the first wake-up sub-circuit is connected with a first detection interface (I1) of the MCU; the input end of the second wake-up sub-circuit is connected with a second signal output end (X2) of the whole vehicle, and the output end of the second wake-up sub-circuit is connected with a second detection interface (I2) of the MCU; the output end of the first wake-up sub-circuit and the output end of the second wake-up sub-circuit are connected in parallel and then are connected with a wake-up interface (I0) of the MCU.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a wake-up circuit for an MCU. Background Art

[0002] In automotive electronics, to ensure sufficiently low quiescent current after entering sleep mode, only the INT (interrupt) interface for wake-up is often retained. If only one INT (interrupt) interface is retained after the MCU enters sleep mode, it cannot support wake-up requests from more than two external interrupts, thus failing to meet customer requirements. Summary of the Invention

[0003] Aiming at the technical problem in the prior art that the MCU cannot perform multi-path wake-up judgment, the utility model proposes a wake-up circuit for the MCU.

[0004] In order to achieve the above objectives, the present invention provides the following technical solutions:

[0005] A wake-up circuit for an MCU, comprising a first wake-up sub-circuit and a second wake-up sub-circuit;

[0006] The input end of the first wake-up sub-circuit is connected to the first signal output end X1 of the whole vehicle, and the output end of the first wake-up sub-circuit is connected to the first detection interface I1 of the MCU; the input end of the second wake-up sub-circuit is connected to the second signal output end X2 of the whole vehicle, and the output end of the second wake-up sub-circuit is connected to the second detection interface I2 of the MCU; the output end of the first wake-up sub-circuit and the output end of the second wake-up sub-circuit are connected in parallel to the wake-up interface I0 of the MCU.

[0007] Preferably, the first wake-up sub-circuit is:

[0008] The first signal output terminal of the vehicle is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to one end of the third resistor, and the other end of the third resistor is connected to one end of the first capacitor, one end of the fourth resistor, and one end of the fifth resistor, respectively; the other end of the first capacitor is grounded, and the other end of the fourth resistor is grounded; the other end of the fifth resistor is connected to the base of the first switch, and the emitter of the first switch is grounded;

[0009] The collector of the first switch is respectively connected to one end of the sixth resistor, one end of the second capacitor, the cathode of the first diode, and the cathode of the second diode, the other end of the sixth resistor is input with the first voltage, and the other end of the second capacitor is grounded; the anode of the first diode is respectively connected to one end of the seventh resistor and the first detection interface of the MCU, and the other end of the seventh resistor is input with the second voltage; the anode of the second diode is respectively connected to one end of the eighth resistor and one end of the third capacitor, the other end of the eighth resistor is input with the third voltage, and the other end of the third capacitor is grounded.

[0010] Preferably, the model of the first switch is S-LMBT3904LT1G.

[0011] Preferably, the model of the first diode and the second diode is RB531SM-30FHT2R.

[0012] Preferably, the second wake-up sub-circuit is:

[0013] The second signal output end of the vehicle is connected to one end of a ninth resistor, the other end of the ninth resistor is connected to one end of a tenth resistor, the other end of the tenth resistor is connected to one end of an eleventh resistor, and the other end of the eleventh resistor is connected to one end of a fourth capacitor, one end of a twelfth resistor, and one end of a thirteenth resistor, respectively; the other end of the fourth capacitor is grounded, and the other end of the twelfth resistor is grounded; the other end of the thirteenth resistor is connected to the base of the second switch, and the emitter of the second switch is grounded;

[0014] The collector of the second switch is respectively connected to one end of the fourteenth resistor, one end of the fifth capacitor, the cathode of the third diode, and the cathode of the fourth diode. The other end of the fourteenth resistor is input with the fourth voltage, and the other end of the fifth capacitor is grounded. The anode of the third diode is respectively connected to one end of the fifteenth resistor and one end of the third capacitor. The other end of the fifteenth resistor is connected to the wake-up interface of the MCU.

[0015] The anode of the fourth diode is connected to one end of the sixteenth resistor and the second detection interface of the MCU respectively, and the other end of the sixteenth resistor is input with the fifth voltage.

[0016] Preferably, the model of the second switch is S-LMBT3904LT1G.

[0017] Preferably, the model of the third diode and the fourth diode is RB531SM-30FHT2R.

[0018] In summary, due to the adoption of the above technical solution, compared with the prior art, the present invention has at least the following beneficial effects:

[0019] The utility model first wakes up the MCU from sleep mode by identifying an external signal, and then the MCU identifies the source of the wake-up signal in multiple wake-up sub-circuits, thereby waking up the MCU, meeting the customer's requirements for multiple signal inputs and improving practicality and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of an exemplary wake-up circuit for an MCU according to the present invention.

[0021] Figure 2The figure is a schematic diagram of a wake-up circuit principle for an MCU according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the following examples and specific implementation methods. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the present invention fall within the scope of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0024] like Figure 1 As shown, the utility model provides a wake-up circuit for MCU, including a first wake-up sub-circuit and a second wake-up sub-circuit;

[0025] The input end of the first wake-up sub-circuit is connected to the first signal output end X1 of the whole vehicle, and the output end of the first wake-up sub-circuit is connected to the first detection interface I1 of the MCU; the input end of the second wake-up sub-circuit is connected to the second signal output end X2 of the whole vehicle, and the output end of the second wake-up sub-circuit is connected to the second detection interface I2 of the MCU; the output end of the first wake-up sub-circuit and the output end of the second wake-up sub-circuit are connected in parallel to the wake-up interface I0 of the MCU.

[0026] When the first signal output terminal X1 and / or the second signal output terminal X2 of the vehicle outputs a wake-up signal, the corresponding first wake-up sub-circuit and / or the second wake-up sub-circuit operates, and the MCU's wake-up interface I0 detects an external signal input, thereby waking up the MCU; then the MCU's first detection interface I1 and / or the second detection interface I2 detect the corresponding level status to determine which wake-up signal is the wake-up source.

[0027] In this embodiment, Figure 2 As shown, the first wake-up sub-circuit includes a first switch Q1:

[0028] The first signal output terminal X1 of the vehicle is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is respectively connected to one end of the first capacitor C1, one end of the fourth resistor R4, and one end of the fifth resistor R5. The other end of the first capacitor C1 is grounded, and the other end of the fourth resistor R4 is grounded. The other end of the fifth resistor R5 is connected to the base of the first switch Q1, and the emitter of the first switch Q1 is grounded.

[0029] The collector of the first switch Q1 is respectively connected to one end of the sixth resistor R6, one end of the second capacitor C2, the cathode of the first diode D1, and the cathode of the second diode D2. The other end of the sixth resistor R6 is input with the first voltage (5V), and the other end of the second capacitor C2 is grounded. The anode of the first diode D1 is respectively connected to one end of the seventh resistor R7 and the first detection interface I1 of the MCU. The other end of the seventh resistor R7 is input with the second voltage (5V). The anode of the second diode D2 is respectively connected to one end of the eighth resistor R8 and one end of the third capacitor C3. The other end of the eighth resistor R8 is input with the third voltage (5V), and the other end of the third capacitor C3 is grounded.

[0030] In this embodiment, the model of the first switch Q1 is S-LMBT3904LT1G; the model of the first diode D1 and the second diode D2 is RB531SM-30FHT2R.

[0031] In this embodiment, the second wake-up sub-circuit includes a second switch Q2:

[0032] The second signal output terminal X2 of the vehicle is connected to one end of a ninth resistor R9, the other end of the ninth resistor R9 is connected to one end of a tenth resistor R10, the other end of the tenth resistor R10 is connected to one end of an eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to one end of a fourth capacitor C4, one end of a twelfth resistor R12, and one end of a thirteenth resistor R13, respectively. The other end of the fourth capacitor C4 is grounded, and the other end of the twelfth resistor R12 is grounded. The other end of the thirteenth resistor R13 is connected to the base of the second switch Q2, and the emitter of the second switch Q2 is grounded.

[0033] The collector of the second switch Q2 is respectively connected to one end of the fourteenth resistor R14, one end of the fifth capacitor C5, the cathode of the third diode D3, and the cathode of the fourth diode D4. The other end of the fourteenth resistor R14 is input with the fourth voltage (5V), and the other end of the fifth capacitor C5 is grounded. The anode of the third diode D3 is respectively connected to one end of the fifteenth resistor R15 and one end of the third capacitor C3. The other end of the fifteenth resistor R15 is connected to the wake-up interface I0 of the MCU.

[0034] An anode of the fourth diode D4 is connected to one end of the sixteenth resistor R16 and the second detection interface I2 of the MCU respectively, and the other end of the sixteenth resistor R16 is input with the fifth voltage (5V).

[0035] In this embodiment, the model of the second switch Q2 is S-LMBT3904LT1G; the model of the third diode D3 and the fourth diode D4 is RB531SM-30FHT2R.

[0036] When the X1 input is high, Q1 turns on, and D1 and D2 are turned on at the same time. Current flows from the 5V power supply of R7 / R8 to diodes D1 / D2, and then flows to GND through Q1. At this time, the voltage at the anode of D1 / D2 is the forward voltage of the diode. The forward voltage of this type of diode is 0.35V. The anode of the diode is connected to the MCU. Therefore, the MCU detects a low level at this time and determines that the external wake-up is X1.

[0037] In this embodiment, the first, second, third, fourth, and fifth voltages are all 5V input voltages, which are used to pull up the entire wake-up circuit during sleep. C3 is used for filtering to ensure the stability of the detection interface I0 signal detection.

[0038] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A wake-up circuit for MCU, characterized in that , including a first wake-up sub-circuit and a second wake-up sub-circuit; The input end of the first awakening subcircuit is connected to the first signal output end (X1) of the vehicle, and the output end of the first awakening subcircuit is connected to the first detection interface (I1) of the MCU; the input end of the second awakening subcircuit is connected to the second signal output end (X2) of the vehicle, and the output end of the second awakening subcircuit is connected to the second detection interface (I2) of the MCU; the output end of the first awakening subcircuit and the output end of the second awakening subcircuit are connected in parallel to the awakening interface (I0) of the MCU.

2. A wake-up circuit for MCU as claimed in claim 1, characterized in that ,The first wake-up sub-circuit is: The first signal output terminal of the vehicle is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to one end of the third resistor, and the other end of the third resistor is connected to one end of the first capacitor, one end of the fourth resistor, and one end of the fifth resistor, respectively; the other end of the first capacitor is grounded, and the other end of the fourth resistor is grounded; the other end of the fifth resistor is connected to the base of the first switch, and the emitter of the first switch is grounded; The collector of the first switch is respectively connected to one end of the sixth resistor, one end of the second capacitor, the cathode of the first diode, and the cathode of the second diode, the other end of the sixth resistor is input with the first voltage, and the other end of the second capacitor is grounded; the anode of the first diode is respectively connected to one end of the seventh resistor and the first detection interface of the MCU, and the other end of the seventh resistor is input with the second voltage; the anode of the second diode is respectively connected to one end of the eighth resistor and one end of the third capacitor, the other end of the eighth resistor is input with the third voltage, and the other end of the third capacitor is grounded.

3. A wake-up circuit for MCU as claimed in claim 2, characterized in that ,The model of the first switch is S-LMBT3904LT1G.

4. A wake-up circuit for MCU as claimed in claim 2, characterized in that ,The models of the first diode and the second diode are RB531SM-30FHT2R.

5. A wake-up circuit for MCU as claimed in claim 1, characterized in that ,The second wake-up sub-circuit is: The second signal output end of the vehicle is connected to one end of a ninth resistor, the other end of the ninth resistor is connected to one end of a tenth resistor, the other end of the tenth resistor is connected to one end of an eleventh resistor, and the other end of the eleventh resistor is connected to one end of a fourth capacitor, one end of a twelfth resistor, and one end of a thirteenth resistor, respectively; the other end of the fourth capacitor is grounded, and the other end of the twelfth resistor is grounded; the other end of the thirteenth resistor is connected to the base of the second switch, and the emitter of the second switch is grounded; The collector of the second switch is respectively connected to one end of the fourteenth resistor, one end of the fifth capacitor, the cathode of the third diode, and the cathode of the fourth diode. The other end of the fourteenth resistor is input with the fourth voltage, and the other end of the fifth capacitor is grounded. The anode of the third diode is respectively connected to one end of the fifteenth resistor and one end of the third capacitor. The other end of the fifteenth resistor is connected to the wake-up interface of the MCU. The anode of the fourth diode is connected to one end of the sixteenth resistor and the second detection interface of the MCU respectively, and the other end of the sixteenth resistor is input with the fifth voltage.

6. A wake-up circuit for MCU as claimed in claim 5, characterized in that ,The model of the second switch is S-LMBT3904LT1G.

7. A wake-up circuit for MCU as claimed in claim 5, characterized in that , the model of the third diode and the fourth diode is RB531SM-30FHT2R.

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