Boost circuit of an infrared remote control

Abstract

The present invention relates to a boost circuit for an infrared remote controller, which includes an inductor, a first PMOS transistor, a capacitor and a second NMOS transistor. By adopting the boost circuit for the infrared remote controller in the present invention and using synchronous rectification technology, not only the power loss of the diode in the rectification process is eliminated, the utilization efficiency of the battery energy is improved, and the service life of the battery is prolonged, but also through an externally connected filter capacitor, when the boost circuit is in the code-sending working state or the stop working state, the load can be powered by the charge stored in the capacitor, and the internal circuit will not have abnormal conditions due to the inductor being unable to supply power to the internal circuit.

Description

Technical Field

[0001] The present invention relates to the field of control technologies, and particularly to the field of circuit technologies, specifically referring to a boost circuit for an infrared remote control. Background Art

[0002] Comparative document 1 (CN 106843027A) discloses a single-battery infrared circuit and a remote control using the same. It adopts the principle of a switching power supply. During the boosting period, the inductor is first charged, and after the charging is completed, the inductor supplies power to the load (microcontroller). However, the circuit using this method has the defects of unstable operation and high power consumption. At the same time, in comparative document 1, the parasitic diode DP1 of the PMOS transistor is used for rectification. Since there is a forward voltage drop of about 0.6V when the parasitic diode is conducting, energy waste will occur during the rectification stage.

[0003] Based on this, there is an urgent need for a circuit structure that can improve stability and working efficiency, so that the remote control using this circuit has sufficient continuous voltage to work, which can not only maintain working stability but also improve working efficiency. Summary of the Invention

[0004] The object of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a boost circuit for an infrared remote control that can improve the battery energy utilization rate.

[0005] In order to achieve the above object, the boost circuit of the infrared remote control of the present invention has the following composition:

[0006] The boost circuit of the infrared remote control is mainly characterized in that the boost circuit includes:

[0007] An inductor, one end of which is connected to the positive terminal of the input voltage;

[0008] A first PMOS transistor, the drain of which is connected to the other end of the inductor, the gate of the first PMOS transistor is used to input a first timing signal, and the source of the first PMOS transistor is the output terminal of the boost circuit;

[0009] A capacitor, the positive electrode of which is connected to the output terminal of the boost circuit, and the negative electrode of the capacitor is grounded;

[0010] A second NMOS transistor, the drain of which is connected between the drain of the first PMOS transistor and the other end of the inductor, the gate of the second NMOS transistor is used to input a second timing signal, and the source of the second NMOS transistor is grounded.

[0011] The boost circuit of the infrared remote controller has a boost working state. In the boost working state, the first timing signal and the second timing signal are synchronous first pulse signals.

[0012] The frequency range of the first pulse signal of the boost circuit of the infrared remote controller is 50KHz to 150KHz.

[0013] The boost circuit of the infrared remote controller further includes:

[0014] A third NMOS transistor. The drain of the third NMOS transistor is used to connect an infrared diode to send a remote control code to the other end of the inductor. The gate of the third NMOS transistor inputs a third timing signal, and the source of the third NMOS transistor is grounded.

[0015] The boost circuit of the infrared remote controller has a code-sending working state. In the code-sending working state, the first timing signal and the third timing signal are both continuous high-level signals, and the second timing signal is a second pulse signal.

[0016] The frequency range of the second pulse signal of the boost circuit of the infrared remote controller is 20KHz to 64KHz.

[0017] The frequency of the second pulse signal of the boost circuit of the infrared remote controller is 38KHz.

[0018] The negative terminal of the input voltage of the boost circuit of the infrared remote controller is grounded.

[0019] The first PMOS transistor, the second NMOS transistor, and the third NMOS transistor of the boost circuit of the infrared remote controller are integrated in the chip of the infrared remote controller, and the output terminal of the boost circuit is the VDD terminal of the chip.

[0020] The input voltage is a single dry battery.

[0021] For the boost circuit of the infrared remote controller in the present invention, the synchronous rectification technology is adopted, which not only eliminates the power loss of the diode during the rectification process, improves the utilization efficiency of the battery energy, and prolongs the service life of the battery, but also through an external filter capacitor, when the boost circuit is in the code-sending working state or the stop working state, the load can be powered by the charge stored in the capacitor, and the internal circuit will not have abnormal conditions due to the inductor being unable to supply power to the internal circuit. Description of the Drawings

[0022] Figure 1 It is a schematic connection structure diagram of the boost circuit of the infrared remote controller of the present invention.

[0023] Figure 2It is the control timing diagram of the boost circuit of the infrared remote controller of the present invention.

[0024] Figure 3 It is the simplified circuit schematic diagram of the boost circuit of the infrared remote controller of the present invention. Detailed implementation manners

[0025] In order to more clearly describe the technical content of the present invention, the following will be further described in combination with specific embodiments.

[0026] The boost circuit of the infrared remote controller includes:

[0027] An inductor, one end of the inductor is connected to the positive terminal of the input voltage;

[0028] A first PMOS transistor, the drain of the first PMOS transistor is connected to the other end of the inductor, the gate of the first PMOS transistor is used to input a first timing signal, and the source of the first PMOS transistor is the output terminal of the boost circuit;

[0029] A capacitor, the positive electrode of the capacitor is connected to the output terminal of the boost circuit, and the negative electrode of the capacitor is grounded;

[0030] A second NMOS transistor, the drain of the second NMOS transistor is connected between the drain of the first PMOS transistor and the other end of the inductor, the gate of the second NMOS transistor is used to input a second timing signal, and the source of the second NMOS transistor is grounded.

[0031] The boost circuit of the infrared remote controller has a boost working state. In the boost working state, the first timing signal and the second timing signal are synchronous first pulse signals.

[0032] The frequency range of the first pulse signal of the boost circuit of the infrared remote controller is 50KHz to 150KHz.

[0033] The boost circuit of the infrared remote controller further includes:

[0034] A third NMOS transistor, the connection between the drain of the third NMOS transistor and the other end of the inductor is used to connect an infrared diode to send a remote control code. The gate of the third NMOS transistor inputs a third timing signal, and the source of the third NMOS transistor is grounded.

[0035] The boost circuit of the infrared remote controller has a code-sending working state. In the code-sending working state, the first timing signal and the third timing signal are both continuous high-level signals, and the second timing signal is a second pulse signal.

[0036] The frequency range of the second pulse signal of the boost circuit of the infrared remote control is 20KHz to 64KHz.

[0037] The frequency of the second pulse signal of the boost circuit of the infrared remote control is 38KHz.

[0038] The negative terminal of the input voltage of the boost circuit of the infrared remote control is grounded.

[0039] The first PMOS transistor, the second NMOS transistor, and the third NMOS of the boost circuit of the infrared remote control are integrated in the chip of the infrared remote control, and the output terminal of the boost circuit is the VDD terminal of the chip.

[0040] The input voltage is a single dry battery.

[0041] In a specific embodiment, please refer to Figure 1 , there are 3 MOS transistors inside the remote control circuit 201, which are the PMOS transistor MP1, the NMOS transistor MN2, and the NMOS transistor NM3. These 3 MOS transistors cooperate to achieve the boost function and the code sending function. The difference is that the present invention adds a VDD port to the remote control circuit 201. The VDD port is connected to the source electrode of the PMOS transistor MP1 inside the remote control circuit 201, and the VDD port is connected to the capacitor C1 outside the remote control circuit 201 to filter VDD, ensuring that there is still enough energy source to work during the inductor charging period and the circuit code sending period. The capacitor C1 can generally use 47μF or 100μF, which can achieve a better filtering effect.

[0042] In a specific embodiment, please refer to Figure 2 , the present invention uses synchronous rectification technology for rectification. The optimized control timing is shown in Figure 2 . It can be seen from the figure that during the boost period, the gate control signal PG1 of the PMOS transistor MP1 is no longer kept high level, but is consistent with the gate control signal of the NMOS transistor MN2 during the boost period. During the discharge stage of the inductor L2, NG2 becomes low level to control MN2 to cut off, and at the same time the PG1 signal also becomes low level to control MP1 to conduct. The inductor current flows through the communication of MP1, and the voltage drop across both ends of the PMOS transistor MP1 is only dozens of mV, greatly reducing the energy waste during the rectification stage and prolonging the life of the dry battery. Therefore, the synchronous rectification method of the present invention improves the current rectification efficiency, reduces the battery power consumption, and can extend the service life of the battery.

[0043] In a specific embodiment, please refer to Figure 3, S_MP1 is the equivalent switch model of PMOS transistor MP1, and S_MN2 is the equivalent switch model of NMOS transistor MN2. Since both MP1 and MN2 operate in the switching mode and have only two states: on and off, they can be equivalent to switches. During the boost period Figure 3 the switches S_MN2 and S_MP1 in Figure 3 are alternately turned on. When S_MN2 is closed, the inductor L2 is connected across the battery BAT2, and the inductor current increases linearly. At this time, S_MP1 is open, and the capacitor C1 connected to the VDD port of the remote control circuit discharges to supply power to the internal circuit of the remote control circuit; then S_MN3 is turned off and S_MP1 is turned on. The inductor current flows through S_MP1 to supply power to the internal circuit of the remote control circuit and simultaneously charges the capacitor C1. The switch S_MP1 in the inductor discharge loop eliminates the power loss on the diode DP1, improves the efficiency of the boost circuit, and can extend the service life of the battery.

[0044] The boost circuit of the infrared remote control in the present invention is adopted. By using the synchronous rectification technology, it not only eliminates the power loss of the diode during the rectification process, improves the utilization efficiency of the battery energy, and extends the service life of the battery, but also, through an external filter capacitor, enables the load to be powered by the charge stored in the capacitor when the boost circuit is in the state of sending codes or stopped working, without causing abnormal conditions in the internal circuit due to the inability of the inductor to supply power to the internal circuit.

[0045] In this specification, the present invention has been described with reference to its specific embodiments. However, it is obvious that various modifications and transformations can still be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.

Claims

1. A boosting circuit for an infrared remote control, characterized in that, The described boost circuit includes: An inductor, one end of which is connected to the positive terminal of the input voltage; A first PMOS transistor, the drain of which is connected to the other end of the inductor, the gate of the first PMOS transistor is used to input a first timing signal, and the source of the first PMOS transistor is the output terminal of the boost circuit; A capacitor, the positive electrode of which is connected to the output terminal of the boost circuit, and the negative electrode of the capacitor is grounded; A second NMOS transistor, the drain of which is connected between the drain of the first PMOS transistor and the other end of the inductor, the gate of the second NMOS transistor is used to input a second timing signal, and the source of the second NMOS transistor is grounded; Wherein, the boost circuit has a boost working state, and in the boost working state, the first timing signal and the second timing signal are synchronous first pulse signals.

2. The boost circuit of the infrared remote controller according to claim 1, characterized in that The frequency range of the first pulse signal is 50KHz to 150KHz.

3. The boost circuit of the infrared remote controller according to claim 1, characterized in that The boost circuit further includes: A third NMOS transistor, between the drain of which and the other end of the inductor is used to connect an infrared diode for sending a remote control code, the gate of the third NMOS transistor inputs a third timing signal, and the source of the third NMOS transistor is grounded.

4. The boost circuit of the infrared remote controller according to claim 3, characterized in that, The boost circuit has a code-sending working state, and in the code-sending working state, the first timing signal and the third timing signal are both continuous high-level signals, and the second timing signal is a second pulse signal.

5. The boost circuit of the infrared remote controller according to claim 4, characterized in that The frequency range of the second pulse signal is 20KHz to 64KHz.

6. The boost circuit of the infrared remote controller according to claim 5, wherein The frequency of the second pulse signal is 38KHz.

7. The boost circuit of the infrared remote controller according to any one of claims 1 to 6, characterized in that, The negative terminal of the input voltage is grounded.

8. The boost circuit of the infrared remote controller according to any one of claims 1 to 6, characterized in that The first PMOS transistor, the second NMOS transistor and the third NMOS transistor are integrated in the chip of the infrared remote controller, and the output terminal of the boost circuit is the VDD terminal of the chip.

9. The boost circuit of the infrared remote controller according to claim 1, wherein, The input voltage is a single dry battery.

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