Power management system and method for optimizing static current

Abstract

The present invention discloses a power management system for optimizing quiescent current, including a battery, a power management module, a microcontroller and a load, wherein the battery is connected to the power management module; the microcontroller and the load are integrated together, or the microcontroller and the load are separately arranged; the power management module includes a switching circuit, an LDO voltage-stabilized power supply circuit and a battery power supply circuit; the microcontroller includes a voltage acquisition unit and a switch control unit; the voltage acquisition unit is used to acquire the voltage value of the battery; the switch control unit is used to receive the battery voltage value acquired by the voltage acquisition unit, and compare it with a preset threshold voltage, and generate a control signal according to the comparison result; the switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load, or the battery power supply circuit to supply power to the load according to the control signal output by the switch control unit. The power management system for optimizing quiescent current of the present invention can maintain a small quiescent current within the full voltage range, and extend the battery life of low-power products.

Description

Technical Field

[0001] The invention relates to a power management system for optimizing static current, and also relates to a power management method for optimizing static current. Background Art

[0002] The quiescent current of the microcontroller is an important parameter for the battery life of low-power products powered by batteries. The smaller the quiescent current of the microcontroller, the longer the battery life of the product using the microcontroller; conversely, the shorter it is. For low-power products with an operating current of only one or two hundred uA, using an LDO voltage-stabilized power supply circuit is an ideal choice, with high efficiency, low noise, small footprint, and low quiescent current.

[0003] The LDO voltage-stabilized power supply circuit mainly includes a series adjustment tube, a sampling resistor and a comparison amplifier. The sampling voltage is added to the inverting input terminal of the comparison amplifier and compared with the reference voltage added to the non-inverting input terminal. The difference between the two is amplified by the comparison amplifier to control the voltage drop of the series adjustment tube, thereby stabilizing the output voltage. out When it decreases, the difference between the reference voltage and the sampling voltage increases, the driving current output by the comparison amplifier increases, and the voltage drop of the series adjustment tube decreases, thereby increasing the output voltage. On the contrary, if the output voltage exceeds the required set value, the front driving current output by the comparison amplifier decreases, thereby reducing the output voltage. During the power supply process, the output voltage correction is performed continuously. This adjustment characteristic of the LDO voltage-stabilized power supply circuit determines that it has the following limitations: when the input voltage of the LDO is greater than its output voltage, the quiescent current of the LDO is very small and maintained at the uA level; when the input voltage of the LDO is less than or equal to its output voltage, its quiescent current is 5 to 10 times that of the first case. The reason is that when the input voltage is less than or equal to its output voltage, the comparison amplifier will quickly amplify the error signal between the output feedback voltage and the reference voltage, and then amplify it to the output through the series adjustment tube, trying to increase the output voltage.

[0004] The LDO voltage-stabilized power supply circuit with the above limitations cannot maintain a small quiescent current within the full voltage range when applied to battery-powered low-power products. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a charging system for optimizing quiescent current, which can maintain a relatively small quiescent current within the full voltage range and extend the battery life of low-power products.

[0006] In order to solve the above technical problems, the present invention provides a power management system for optimizing static current, comprising a battery, a power management module, a microcontroller and a load, wherein the battery is connected to the power management module; the microcontroller and the load are integrated together, or the microcontroller and the load are separately arranged;

[0007] The power management module includes a switch circuit, an LDO voltage-stabilized power supply circuit and a battery power supply circuit;

[0008] The microcontroller includes a voltage acquisition unit and a switch control unit; the voltage acquisition unit is used to acquire the voltage value of the battery; the switch control unit is used to receive the battery voltage value acquired by the voltage acquisition unit, and compare it with a preset threshold voltage, and generate a control signal according to the comparison result;

[0009] The switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load, or controls the battery power supply circuit to supply power to the load according to the control signal output by the switch control unit.

[0010] In a preferred embodiment of the present invention, it further includes that when the voltage value of the battery is greater than the threshold voltage, the switch circuit controls the LDO voltage stabilizing power supply circuit to supply power to the load; when the voltage value of the battery is less than or equal to the threshold voltage, the switch circuit controls the battery power supply circuit to supply power to the load.

[0011] In a preferred embodiment of the present invention, the switch circuit further includes a switch 1 K1 and a switch 2 K2, and the switch 1 and the switch 2 are turned on or off independently of each other; the switch 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch 2 is connected in series between the positive electrode of the battery and the load.

[0012] In a preferred embodiment of the present invention, the switching circuit further includes a single-pole double-throw switch, the single-pole double-throw switch has a switch contact 1 and a switch contact 2 associated with working states, the switch contact 1 is connected in series between the positive pole of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch contact 2 is connected in series between the positive pole of the battery and the load.

[0013] In a preferred embodiment of the present invention, the voltage acquisition unit further includes a sampling resistor 1 R1 and a sampling resistor 2 R2, and the sampling resistor 1 and the sampling resistor 2 are connected in series and connected as a whole between the positive electrode and the negative electrode of the battery; a node A where the sampling resistor 1 and the sampling resistor 2 are connected in series is connected to the input end of the voltage acquisition unit.

[0014] In a preferred embodiment of the present invention, the voltage acquisition unit further includes periodically acquiring the battery voltage, and the acquisition period is 1 to 5 minutes.

[0015] In order to solve the above technical problems, the present invention also provides a power management method for optimizing static current, which is used to supply power to a load, comprising the following steps:

[0016] The voltage acquisition unit acquires the voltage value Vi of the battery;

[0017] The switch control unit receives the battery voltage value Vi collected by the voltage collection unit, compares it with a preset threshold voltage Vr, and generates a control signal according to the comparison result;

[0018] The switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load, or the battery power supply circuit to supply power to the load according to the control signal output by the switch control unit: when the voltage value Vi of the battery is greater than a preset threshold voltage Vr, the switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load; when the voltage value Vi of the battery is less than or equal to the preset threshold voltage Vr, the switch circuit controls the battery power supply circuit to supply power to the load.

[0019] In a preferred embodiment of the present invention, the switching circuit further includes a single-pole double-throw switch, the single-pole double-throw switch has a switch contact 1 and a switch contact 2 associated with working states, the switch contact 1 is connected in series between the positive pole of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch contact 2 is connected in series between the positive pole of the battery and the load.

[0020] In a preferred embodiment of the present invention, the switch circuit further includes a switch 1 K1 and a switch 2 K2, and the switch 1 and the switch 2 are turned on or off independently of each other; the switch 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch 2 is connected in series between the positive electrode of the battery and the load.

[0021] In a preferred embodiment of the present invention, the voltage acquisition unit further includes periodically acquiring the battery voltage, and the acquisition period is 1 to 5 minutes.

[0022] The power management system of the present invention optimizes the static current, uses two power supply modes, namely, direct battery power supply and LDO conversion power supply, to replace the traditional single power supply mode of LDO conversion power supply to supply power to the load, and adjusts the current power supply mode according to the actual voltage value of the battery: when the voltage value of the battery is greater than a preset threshold voltage, the battery supplies power to the load after conversion by the LDO voltage-stabilizing power supply circuit; when the voltage value of the battery is less than or equal to the preset threshold voltage, the battery directly supplies power to the load. After use, the power management system can maintain a small static current within the full voltage range, thereby extending the battery life of low-power products.

[0023] The present invention optimizes the power management method of quiescent current, ensures that charging products can maintain a relatively small quiescent current within the full voltage range, and prolongs the battery life of low-power products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a circuit schematic diagram of a power management system in a preferred embodiment of the present invention;

[0025] Figure 2 is a circuit schematic diagram of a power management system in a second embodiment of the present invention;

[0026] Figure 3 It is a circuit schematic diagram of a power management system in which a battery supplies power to a load after being converted by an LDO voltage-stabilized power supply circuit in a preferred embodiment of the present invention;

[0027] Figure 4 It is a circuit schematic diagram of a power management system in which a battery power supply circuit supplies power to a load in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0029] Embodiment 1

[0030] like Figure 1-2 As shown, this embodiment discloses a power management system for optimizing static current, including a battery, a power management module, a microcontroller and a load, wherein the battery is connected to the power management module; according to actual use needs, the above-mentioned microcontroller and load are integrated together, or are independently set separately.

[0031] The power management module includes a switch circuit, an LDO voltage-stabilized power supply circuit and a battery power supply circuit.

[0032] Specifically, the input end of the LDO voltage-stabilized power supply circuit is connected to the positive electrode of the battery, and the output end is connected to the load; the input end of the battery power supply circuit is connected to the positive electrode of the battery, and the output end is connected to the load. With this design, the load can have two power supply modes:

[0033] Power supply mode 1: the battery supplies power to the load after being converted by the LDO voltage stabilization circuit;

[0034] Power supply mode 2: The battery directly supplies power to the load through the battery power supply circuit.

[0035] In addition, when the microcontroller and the load are integrated together, the battery power supply circuit or the LDO voltage-stabilized power supply circuit supplies power to the load while also supplying power to the operation of the microcontroller; when the microcontroller and the load are separately set up, the battery power supply circuit or the LDO voltage-stabilized power supply circuit supplies power to the load.

[0036] The microcontroller includes a voltage acquisition unit and a switch control unit; specifically, the voltage acquisition unit is used to acquire the voltage value Vi of the battery, and transmit the acquired battery voltage value Vi to the switch control unit, and the switch control unit stores a preset threshold voltage Vr. In the technical solution of this embodiment, the preset threshold voltage Vr is a voltage value related to the LDO voltage-stabilized power supply circuit. In the technical solution of this embodiment, the LDO voltage-stabilized power supply circuit includes a low-dropout linear regulator LDO, and the preset threshold voltage Vr=V1+V2.

[0037] Among them, V1 is the input-output voltage difference of the low-dropout linear regulator LDO. Once the model of the low-dropout linear regulator LDO is selected, the input-output voltage difference V1 is a fixed value.

[0038] In addition, once the model of the low-dropout linear regulator LDO is selected, its stable output voltage value is a fixed value Vo, that is, its stable output voltage value Vo is a known parameter of the low-dropout linear regulator LDO. For example, the factory parameters of a low-dropout linear regulator LDO include a quiescent current of 5uA and an output voltage of 3.6V. The 3.6V here is the stable output voltage value Vo of the LDO.

[0039] The formula Vr=V1+V2, where V2 is Vo described above, which is the fixed voltage of the low dropout linear regulator LDO of the selected model.

[0040] The switch control unit compares the battery voltage value Vi and the threshold voltage Vr, and generates a control signal according to the comparison result. The switch circuit controls the LDO voltage stabilizing power supply circuit to supply power to the load, or the battery power supply circuit to supply power to the load according to the control signal output by the switch control unit.

[0041] Specifically, when Vi>Vr, the switch circuit controls the LDO voltage regulator circuit to supply power to the load, and enters the following state: Figure 3 The first power supply mode shown is: the battery supplies power to the load after being converted by the LDO voltage stabilization power supply circuit.

[0042] When Vi≤Vr, the switch circuit controls the battery power supply circuit to supply power to the load, and the Figure 4 The second power supply mode shown is: the battery directly supplies power to the load through the battery power supply circuit.

[0043] In the first power supply mode, the quiescent current of the power management system is: the quiescent current of the low-dropout linear regulator LDO + the quiescent current of the switching circuit + the quiescent current of the voltage acquisition unit.

[0044] In the second power supply mode, the quiescent current of the power management system is: the quiescent current of the switching circuit + the quiescent current of the voltage acquisition unit.

[0045] Compared with the traditional single power supply mode, the above two power supply mode switching power supply mode can save 30~40uA of static current within the full voltage range, which is beneficial to extend the battery life of low-power products.

[0046] As shown in Table 1, the voltage range of the battery is 2.5V to 4.2V, and V2 of the low-dropout linear regulator LDO is 3.6V. The static current distribution of the power management system in the technical solution of this embodiment within the full voltage range is:

[0047]

[0048] As shown in Table 2, the static current distribution of the power management system in the traditional power supply mode under the same conditions within the full voltage range is:

[0049]

[0050] Comparing Table 1 and Table 2, the power management system in the technical solution of this embodiment can maintain a small static current within the full voltage range, and extend the battery life of low-power products after use.

[0051] In the preferred technical solution of the present invention, the switch circuit includes switch 1 K1 and switch 2 K2; the switch 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch 2 is connected in series between the positive electrode of the battery and the load. When switch 1 K1 is turned on and switch 2 K2 is turned off, the current power supply mode of the microcontroller is the first power supply mode; when switch 2 K2 is turned on and switch 1 K1 is turned off, the current power supply mode of the microcontroller is the second power supply mode.

[0052] In addition, during actual use, the on or off of switch one or switch two has a delay. When the on delay of the on switch is longer than the off delay of the off switch, the power supply of the microcontroller cannot be continuous, and there is a momentary power outage. The momentary power outage of the microcontroller will have a fatal impact on the chip. Based on this, in order to achieve continuous power supply of the microcontroller, in the preferred technical solution of the present invention, the above-mentioned switch one K1 and switch two K2 are two independently working switches, which are independently turned on or off. In the first power supply mode (powered by the LDO voltage-stabilized power supply circuit): first turn on switch two K2, and then turn off switch one K1; in the second power supply mode (powered by the battery power supply circuit): first turn on switch one K1, and then switch two K2, so as to achieve continuous power supply of the microcontroller.

[0053] As another technical solution of the present invention, without considering the continuous power supply of the microcontroller, the switch circuit includes a single-pole double-throw switch, the single-pole double-throw switch has a switch contact 1 and a switch contact 2 associated with the working state, the switch contact 1 is connected in series between the positive pole of the battery and the input end of the LDO voltage-stabilized power supply circuit, or between the output end of the LDO voltage-stabilized power supply circuit and the power input end of the microcontroller; the switch contact 2 is connected in series between the positive pole of the battery and the power input end of the microcontroller. When the switch contact 1 is turned on and the switch contact 2 is turned off, the current power supply mode of the microcontroller is the first power supply mode; when the switch contact 2 is turned on and the switch contact 1 is turned off, the current power supply mode of the microcontroller is the second power supply mode.

[0054] The voltage acquisition unit is used to acquire the voltage value of the battery. The voltage acquisition unit periodically acquires the battery voltage, and the acquisition period is 1 to 5 minutes.

[0055] The voltage acquisition unit includes a sampling resistor R1 and a sampling resistor R2. The sampling resistor R1 and the sampling resistor R2 are connected in series and connected between the positive electrode and the negative electrode of the battery. The series node A between the sampling resistor R1 and the sampling resistor R2 is connected to the input end of the voltage acquisition unit.

[0056] On the other hand, in the technical solution of this embodiment, the two power supply modes of the microcontroller are dynamically adjustable. Without replacing components, a power management system can be used in a variety of scenarios.

[0057] Embodiment 2

[0058] This embodiment discloses a power management method for optimizing static current. The power management system in the first embodiment is used to charge a microcontroller. The components of the power management system are shown in the first embodiment and will not be described in detail here. The method for power management using the power management system specifically includes the following steps:

[0059] Collect the battery voltage value Vi;

[0060] Compare the battery voltage value Vi with a preset threshold voltage Vr;

[0061] When the voltage value Vi of the battery is greater than a preset threshold voltage Vr, the switch circuit controls the LDO voltage stabilizing power supply circuit to supply power to the load, and the battery supplies power to the load after conversion by the LDO voltage stabilizing power supply circuit;

[0062] When the voltage value Vi of the battery is less than or equal to a preset threshold voltage Vr, the switch circuit controls the battery power supply circuit to supply power to the load, and the battery directly supplies power to the load.

[0063] The battery supplies power to the above load after conversion by the LDO voltage stabilizing power supply circuit, and the battery directly supplies power to the load. The implementation and switching process of these two power supply modes are the same as those described in Example 1 and will not be repeated here.

[0064] The present invention optimizes the power management method of quiescent current, ensures that charging products can maintain a relatively small quiescent current within the full voltage range, and prolongs the battery life of low-power products.

[0065] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A power management system for optimizing quiescent current, characterized in that: It includes a battery, a power management module, a microcontroller and a load, wherein the battery is connected to the power management module; the microcontroller and the load are integrated together, or the microcontroller and the load are separately arranged; The power management module includes a switch circuit, an LDO voltage-stabilized power supply circuit and a battery power supply circuit; The microcontroller includes a voltage acquisition unit and a switch control unit; the voltage acquisition unit is used to acquire the voltage value of the battery; The switch control unit is used to receive the battery voltage value collected by the voltage collection unit, compare it with a preset threshold voltage, and generate a control signal according to the comparison result; The switch circuit controls the LDO voltage stabilizing power supply circuit to supply power to the load according to the control signal output by the switch control unit, or controls the battery power supply circuit to supply power to the load; When the voltage value of the battery is greater than the threshold voltage, the switch circuit controls the LDO voltage stabilization power supply circuit to supply power to the load; when the voltage value of the battery is less than or equal to the threshold voltage, the switch circuit controls the battery power supply circuit to supply power to the load; Wherein, the threshold voltage is equal to the sum of the input-output voltage difference of the low voltage dropout linear regulator LDO in the LDO voltage-stabilized power supply circuit and the stable output value of the low voltage dropout linear regulator LDO; A stable output value of the low-dropout linear regulator LDO is obtained according to the model of the low-dropout linear regulator LDO.

2. The power management system for optimizing static current according to claim 1, characterized in that: The switch circuit comprises a switch 1 (K1) and a switch 2 (K2), wherein the switch 1 and the switch 2 are turned on or off independently of each other; the switch 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch 2 is connected in series between the positive electrode of the battery and the load.

3. The power management system for optimizing static current according to claim 1, characterized in that: The switch circuit includes a single-pole double-throw switch, which has a switch contact 1 and a switch contact 2 associated with working states. The switch contact 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch contact 2 is connected in series between the positive electrode of the battery and the load.

4. The power management system for optimizing static current according to claim 1, characterized in that: The voltage acquisition unit includes a sampling resistor 1 (R1) and a sampling resistor 2 (R2), wherein the sampling resistor 1 and the sampling resistor 2 are connected in series and are connected between the positive electrode and the negative electrode of the battery; a node A where the sampling resistor 1 and the sampling resistor 2 are connected in series is connected to an input end of the voltage acquisition unit.

5. The power management system for optimizing static current according to claim 1 or 4, characterized in that: The voltage acquisition unit periodically acquires the battery voltage, and the acquisition period is 1 to 5 minutes.

6. A power management method for optimizing quiescent current, used to supply power to a load, characterized in that: The following steps are included: The voltage acquisition unit acquires the voltage value Vi of the battery; The switch control unit receives the battery voltage value Vi collected by the voltage collection unit, compares it with a preset threshold voltage Vr, and generates a control signal according to the comparison result; The switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load, or controls the battery power supply circuit to supply power to the load according to the control signal output by the switch control unit: when the voltage value Vi of the battery is greater than the preset threshold voltage Vr, the switch circuit controls the LDO voltage-stabilized power supply circuit to supply power to the load; when the voltage value Vi of the battery is less than or equal to the preset threshold voltage Vr, the switch circuit controls the battery power supply circuit to supply power to the load; Wherein, the threshold voltage Vr is equal to the sum of the input-output voltage difference of the low voltage dropout linear regulator LDO in the LDO voltage-stabilized power supply circuit and the stable output value of the low voltage dropout linear regulator LDO; A stable output value of the low-dropout linear regulator LDO is obtained according to the model of the low-dropout linear regulator LDO.

7. The power management method for optimizing static current according to claim 6, characterized in that: The switch circuit includes a switch 1 K1 and a switch 2 K2, and the switch 1 and the switch 2 are turned on or off independently of each other; the switch 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch 2 is connected in series between the positive electrode of the battery and the load.

8. The power management method for optimizing static current according to claim 6, characterized in that: The switch circuit includes a single-pole double-throw switch, which has a switch contact 1 and a switch contact 2 associated with working states. The switch contact 1 is connected in series between the positive electrode of the battery and the input end of the LDO voltage-stabilized power supply circuit, or in series between the output end of the LDO voltage-stabilized power supply circuit and the load; the switch contact 2 is connected in series between the positive electrode of the battery and the load.

9. The power management method for optimizing static current according to claim 6, characterized in that: The voltage acquisition unit periodically acquires the battery voltage, and the acquisition period is 1 to 5 minutes.

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