A light-load detection system

Abstract

The present invention relates to the field of electronic technology, and in particular to a light load detection system, which includes: a detection module, whose input end is connected to the battery voltage to detect a detection signal corresponding to the output voltage value of the battery voltage; an encoding module, whose input end is connected to the output end of the detection module to encode the detection signal to output the encoding result; a logic module, whose input end is connected to the output end of the encoding module, to perform a logic operation according to the encoding result to obtain the load current corresponding to the detection signal; when it is detected that the load current corresponding to the detection signal is small, a light load exit signal is output. Beneficial effect: By detecting the detection signal corresponding to the output voltage value of the battery voltage, and then encoding and logically operating, the load current corresponding to the detection signal can be obtained by searching the code. When the load current found is small, a light load exit signal is detected, without adding external devices and additional chip pins, and it is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a light load detection system. Background Art

[0002] At present, more and more electronic devices need to be charged by lithium battery charging compartments. In order to improve the utilization efficiency of the battery compartment after each charge, the function of detecting the change of load current at the output end of the boost DC converter and exiting charging when the load is light is very practical and necessary.

[0003] However, in the prior art, the load current cannot be directly detected, but a differential operational amplifier is required to detect the voltage difference of the sensing resistor to detect the load current, and a precise external sensing resistor and a pin are required, which increases the complexity and cost of the detection circuit. Therefore, the above problem has become a difficult problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] In view of the above problems existing in the prior art, a light load detection system is now provided.

[0005] The specific technical solutions are as follows:

[0006] The present invention provides a light load detection system, which provides a battery voltage, and includes:

[0007] a detection module, the input end of which is connected to the battery voltage and is used to detect a detection signal corresponding to an output voltage value of the battery voltage;

[0008] an encoding module, the input end of which is connected to the output end of the detection module, and is used to encode the detection signal to output an encoding result;

[0009] a logic module, the input end of which is connected to the output end of the encoding module, and configured to perform a logic operation according to the encoding result to obtain a load current corresponding to the detection signal;

[0010] When it is detected that the load current corresponding to the detection signal is small, a light-load exit signal is output.

[0011] Preferably, the detection module includes a pulse width detection unit for detecting a pulse width signal corresponding to the output voltage value;

[0012] When the load current corresponding to the pulse width signal is small, the light load exit signal is output.

[0013] Preferably, the detection module includes an inductance detection unit, which is used to detect the inductance value corresponding to the output voltage value;

[0014] When the load current corresponding to the inductance value is small, the light-load exit signal is output.

[0015] Preferably, when the inductance value remains unchanged, the pulse width signal is proportional to the load current.

[0016] Preferably, when the pulse width signal remains unchanged, the inductance value is inversely proportional to the load current.

[0017] Preferably, the pulse width detection unit is a phase detector.

[0018] Preferably, the phase detector comprises:

[0019] a first inverter, wherein an input terminal of the first inverter is connected to the battery voltage;

[0020] a second inverter, wherein an input terminal of the second inverter is connected to an output terminal of the first inverter;

[0021] a third inverter, wherein an input terminal of the third inverter is connected to an output terminal of the second inverter;

[0022] a first trigger, wherein an input terminal of the first trigger is connected to an output terminal of the third inverter;

[0023] a fourth inverter, wherein an input terminal of the fourth inverter is connected to an output terminal of the first inverter;

[0024] a delay subunit, wherein an input end of the delay subunit is connected to an output end of the fourth inverter;

[0025] a fifth inverter, wherein an input terminal of the fifth inverter is connected to an output terminal of the delay subunit;

[0026] a second trigger, wherein an input terminal of the second trigger is connected to an output terminal of the fifth inverter;

[0027] A third trigger, wherein a first input terminal of the third trigger is connected to an output terminal of the third inverter, a second input terminal of the third trigger is connected to an output terminal of the second trigger, and an output terminal of the third trigger is connected to an input terminal of the encoding module.

[0028] Preferably, the delay subunit comprises a plurality of delay components, each of which comprises:

[0029] a delay line, the input end of which is connected to the output end of the fourth inverter, and is used for delaying a preset time after receiving the pulse width signal output by the fourth inverter;

[0030] A counter, the output of the counter is connected to the input of the delay line.

[0031] The above technical solution has the following advantages or beneficial effects: by detecting the detection signal corresponding to the output voltage value of the battery voltage, and then performing encoding and logical operations, the load current corresponding to the detection signal can be obtained by looking up the code. When the load current found is small, a light load exit signal is detected. There is no need to add external devices and additional chip pins, and it is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The embodiments of the present invention will be described more fully with reference to the attached drawings, which are provided for illustration and description only and are not intended to limit the scope of the present invention.

[0033] Figure 1 is a functional block diagram of an embodiment of the present invention;

[0034] Figure 2 A principle block diagram of a detection module according to an embodiment of the present invention;

[0035] Figure 3 Another principle block diagram of a detection module according to an embodiment of the present invention;

[0036] Figure 4 Schematic diagram of the circuit structure of the phase detector according to an embodiment of the present invention;

[0037] Figure 5 FIG. 4 is a schematic diagram of the circuit structure of a delay component according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0041] The present invention provides a light load detection system, providing a battery voltage V, such as Figure 1 As shown, including:

[0042] a detection module 1, the input end of which is connected to the battery voltage V, and is used to detect a detection signal corresponding to an output voltage value of the battery voltage V;

[0043] an encoding module 2, the input end of the encoding module 2 being connected to the output end of the detection module 1, and being used for encoding the detection signal to output an encoding result;

[0044] a logic module 3, the input end of the logic module 3 is connected to the output end of the encoding module 2, and is used for performing a logic operation according to the encoding result to obtain a load current corresponding to the detection signal;

[0045] When it is detected that the load current corresponding to the detection signal is small, a light-load exit signal is output.

[0046] Since the load current cannot be detected directly, in this embodiment, the detection module 1 is provided to detect a detection signal corresponding to the output voltage value of the battery voltage V, and the detection signal is further encoded to form a coding table.

[0047] Furthermore, logical operations are performed according to the coding table to obtain the load current corresponding to the detection signal. When the load current corresponding to the detected detection signal is small, a light load exit signal is detected. There is no need to add external devices and additional chip pins, and it is simple and reliable.

[0048] In a preferred embodiment, Figure 2 As shown, the detection module 1 includes a pulse width detection unit 10, which is used to detect a pulse width signal corresponding to the load current;

[0049] When the output voltage value corresponding to the pulse width signal is small, a light load exit signal is output.

[0050] Specifically, in this embodiment, the load current is indirectly detected by detecting the pulse width, that is, by detecting the pulse width signal corresponding to the output voltage value, the load current of the load connected to the power supply voltage V can be obtained. When the load current corresponding to the pulse width signal is detected to be small, a light load exit signal can be detected.

[0051] In a preferred embodiment, Figure 3 As shown, the detection module 1 includes an inductance detection unit 11, which is used to detect the inductance value corresponding to the output voltage value;

[0052] When the load current corresponding to the inductance value is small, a light load exit signal is output.

[0053] Specifically, in this embodiment, the load current is indirectly detected by detecting the inductance value, that is, by detecting the inductance value corresponding to the output voltage value, the load current of the load connected to the power supply voltage V can be obtained. When the load current corresponding to the detected inductance value is small, a light load exit signal can be detected.

[0054] In a preferred embodiment, when the inductance value remains unchanged, the pulse width signal is proportional to the load current.

[0055] Specifically, when the inductance value remains unchanged, the pulse width signal has a one-to-one correspondence with the load current and is encoded, such as shown in the following Table 1:

[0056] Table 1

[0057] Pulse width signal Load current coding 200ns 1mA 001 300ns 2.25mA 010 400ns 4mA 011 500ns 6.25mA 100 600ns 9mA 101 700ns 12.25mA 110

[0058] As shown in Table 1, it is easy to set the relationship between the detected pulse width signal and the load current through coding. When the inductance value remains unchanged, the larger the pulse signal, the larger the corresponding load current. For example, the pulse signal corresponding to code 001 is 200ns, and the corresponding load current is 1mA, the pulse signal corresponding to code 010 is 300ns, and the corresponding load current is 2.25mA, etc. Therefore, the load current can be directly obtained by looking up the coding.

[0059] It should be noted that the encoding in this embodiment can be autonomously encoded according to actual needs.

[0060] In a preferred embodiment, when the pulse width signal remains unchanged, the inductance value is inversely proportional to the load current.

[0061] Specifically, when the pulse width signal is constant, the inductance value and the load current have a one-to-one correspondence and are encoded, such as shown in the following Table 2:

[0062] Table 2

[0063] Inductance Load current coding 4.7uH 2.13mA 001 3.3uH 3.03mA 010 2.2uH 4.55mA 011 500ns 6.67mA 100 1.5uH 10mA 101

[0064] As shown in Table 2 above, by setting the relationship between the detected inductance value and the load current through coding, when the pulse width signal remains unchanged, the smaller the inductance value, the larger the load current, and the larger the inductance value, the smaller the load current, thereby achieving the purpose of detecting the load current.

[0065] In a preferred embodiment, the pulse width detection unit 10 is a phase detector PD.

[0066] Specifically, in this embodiment, the pulse width detection unit 10 in the above technical solution can be implemented by using a phase detector PD. It should be noted that the phase detector PD used in the present invention is only used to illustrate the feasibility and should not be used to limit the protection scope of the present application.

[0067] In a preferred embodiment, Figure 4 As shown, the phase detector PD includes:

[0068] a first inverter P1, wherein an input terminal of the first inverter P1 is connected to a battery voltage V;

[0069] a second inverter P2, wherein an input end of the second inverter P2 is connected to an output end of the first inverter P1;

[0070] a third inverter P3, wherein an input end of the third inverter P3 is connected to an output end of the second inverter P2;

[0071] a first trigger D1, wherein an input terminal of the first trigger D1 is connected to an output terminal of the third inverter P3;

[0072] a fourth inverter P4, wherein an input terminal of the fourth inverter P4 is connected to an output terminal of the first inverter P1;

[0073] a delay subunit 100, wherein the input end of the delay subunit 100 is connected to the output end of the fourth inverter P4;

[0074] a fifth inverter P5, wherein an input terminal of the fifth inverter P5 is connected to an output terminal of the delay subunit 100;

[0075] a second trigger D2, wherein an input terminal of the second trigger D2 is connected to an output terminal of the fifth inverter P5;

[0076] A third trigger D3, a first input terminal of the third trigger D3 is connected to the output terminal of the third inverter P3, a second input terminal of the third trigger P3 is connected to the output terminal of the second trigger D2, and an output terminal of the third trigger P3 is connected to the input terminal of the encoding module 2.

[0077] Specifically, in this embodiment, the phase detector PD is used as a phase detection locking window.

[0078] In a preferred embodiment, the delay subunit 100 includes a plurality of delay components 110, such as Figure 5 As shown, each delay component 110 includes:

[0079] a delay line 111, wherein an input end of the delay line 111 is connected to an output end of the fourth inverter P4, and is used for delaying a preset time after receiving a pulse width signal output by the fourth inverter P4;

[0080] A counter 112 , the output of which is connected to the input of the delay line 111 .

[0081] Specifically, in this embodiment, the delay subunit 100 in the above technical solution includes a plurality of delay components 110. It should be noted that the number of delay components 110 required in this embodiment is determined by the phase detector PD in the above technical solution. When the number of phases detected by the phase detector PD is insufficient, the purpose of ensuring that the number of phases of the phase detector PD is sufficient can be achieved by adding delay components 110.

[0082] Furthermore, within the preset time delayed by the delay line 111 , the number of pulses within the preset time is counted by the counter 112 .

[0083] In a preferred embodiment, the delay subunit 100 further includes a buffer and an AND gate, wherein the buffer is connected between the fourth inverter P4 and the delay line 111 , and the AND gate is connected to the counter 112 .

[0084] It should be noted that the various devices included in the delay component 110 in the present invention are only used to illustrate the feasibility and should not be used to limit the protection scope of the present application.

[0085] The above technical solution has the following advantages or beneficial effects: by detecting the detection signal corresponding to the output voltage value of the battery voltage, and then performing encoding and logical operations, the load current corresponding to the detection signal can be obtained by looking up the code. When the load current found is small, a light load exit signal is detected. There is no need to add external devices and additional chip pins, and it is simple and reliable.

[0086] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A light load detection system provides a battery voltage, characterized in that: include: a detection module, the input end of which is connected to the battery voltage and is used to detect a detection signal corresponding to an output voltage value of the battery voltage; an encoding module, the input end of which is connected to the output end of the detection module, and is used to encode the detection signal to output an encoding result; a logic module, the input end of which is connected to the output end of the encoding module, and configured to perform a logic operation according to the encoding result to obtain a load current corresponding to the detection signal; When it is detected that the load current corresponding to the detection signal is small, a light load exit signal is output; The detection module includes a pulse width detection unit, which is used to detect the pulse width signal corresponding to the output voltage value; When the load current corresponding to the pulse width signal is small, the light load exit signal is output; The pulse width detection unit is a phase detector; The phase detector comprises: a first inverter, wherein an input terminal of the first inverter is connected to the battery voltage; a second inverter, wherein an input terminal of the second inverter is connected to an output terminal of the first inverter; a third inverter, wherein an input terminal of the third inverter is connected to an output terminal of the second inverter; a first trigger, wherein an input terminal of the first trigger is connected to an output terminal of the third inverter; a fourth inverter, wherein an input terminal of the fourth inverter is connected to an output terminal of the first inverter; a delay subunit, wherein an input end of the delay subunit is connected to an output end of the fourth inverter; a fifth inverter, wherein an input terminal of the fifth inverter is connected to an output terminal of the delay subunit; a second trigger, wherein an input terminal of the second trigger is connected to an output terminal of the fifth inverter; a third trigger, wherein a first input terminal of the third trigger is connected to the output terminal of the third inverter, a second input terminal of the third trigger is connected to the output terminal of the second trigger, and an output terminal of the third trigger is connected to the input terminal of the encoding module; The delay subunit includes a plurality of delay components, each of which includes: a delay line, the input end of which is connected to the output end of the fourth inverter, and is used for delaying a preset time after receiving the pulse width signal output by the fourth inverter; a counter, wherein an output terminal of the counter is connected to an input terminal of the delay line; The number of the delay components is determined by the phase detector. When the number of phases detected by the phase detector is insufficient, the delay components are added to ensure that the number of phases of the phase detector is sufficient.

2. The light load detection system according to claim 1, characterized in that: The detection module includes an inductance detection unit, which is used to detect the inductance value corresponding to the output voltage value; When the load current corresponding to the inductance value is small, the light-load exit signal is output.

3. The light load detection system according to claim 2, characterized in that: When the inductance value remains unchanged, the pulse width signal is proportional to the load current.

4. The light load detection system according to claim 2, characterized in that: When the pulse width signal remains unchanged, the inductance value is inversely proportional to the load current.

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