CN103972942B - Electronic equipment - Google Patents

Abstract

An electronic device includes a pre-charging circuit and a battery, and the pre-charging circuit is connected with an external power source for charging the battery of the electronic device. The electronic device also includes a fast charging circuit including a switch, a comparator and a NOR gate. The switch is electrically connected between the external power supply and the battery; the comparator is electrically connected to the battery for comparing the battery voltage and the reference voltage; the NOR gate is electrically connected to the pre-charging circuit, the comparator and the switch, and is used to compare the result according to the comparator Output signals with the level signal output by the pre-charging circuit to control the switch on and off. The electronic device uses the original pre-charging circuit plus the designed fast charging circuit to charge the battery of the electronic device, which shortens the charging time.

Description

Electronic equipment

technical field

The invention relates to electronic equipment, in particular to a charging circuit for fast charging the electronic equipment.

Background technique

At present, as the functions of a series of handheld products such as mobile phones and e-books become more and more powerful, the battery capacity of these electronic products is also continuously improved to achieve longer-term use. However, with the existing design, the battery The charging current is below 2A, so when charging a battery with a large capacity, it takes a lot of time to fully charge the battery.

Contents of the invention

The invention provides an electronic device with a fast charging circuit. The fast charging circuit can reach a large charging current, thereby shortening the charging time of the electronic device.

The invention provides an electronic device including a pre-charging circuit and a battery, and the pre-charging circuit is connected with an external power source for charging the battery of the electronic device. The electronic device also includes a fast charging circuit including a switch, a comparator and a NOR gate. The switch is electrically connected between the external power supply and the battery; the comparator is electrically connected to the battery for comparing the battery voltage and the reference voltage; the NOR gate is electrically connected to the pre-charging circuit, the comparator and the switch, and is used for comparing the results according to the comparator Output signals with the level signal output by the pre-charging circuit to control the switch on and off.

Preferably, the precharge circuit outputs a low level to the NOR gate when the battery voltage is lower than the saturation voltage, and outputs a high level to the NOR gate when the battery voltage is not less than the saturation voltage.

Preferably, the comparator outputs a high level to the NOR gate when the battery voltage is lower than the reference voltage, and outputs a low level to the NOR gate when the battery voltage is not lower than the reference voltage.

Preferably, when both the comparator and the pre-charging circuit output a low-level signal, the NOR gate outputs a high-level signal to make the switch conduct; when the pre-charging circuit is inconsistent with the output level signal of the comparator, the NOR gate outputs a low level signal The level signal turns off the switch.

Preferably, the switch is an N-type non-metal oxide field effect transistor, one end of the switch connected to the external power supply is the drain of the N-type non-metal oxide field effect transistor, and one end of the switch connected to the battery is the N-type non-metal oxide field effect transistor. The source, the end connected to the switch and the NOR gate is the gate of the N-type non-metal oxide field effect transistor.

Preferably, the fast charging circuit also includes a first resistor and a second resistor, and the comparator includes a forward input terminal, a reverse input terminal, and an output terminal, wherein the reverse input terminal of the comparator is connected to the battery, and the output terminal of the comparator The NOR gate is connected, the first resistor is connected between the positive input terminal of the comparator and the external power supply, and the second resistor is connected between the positive input terminal of the comparator and ground.

Preferably, the NOR gate includes a first input terminal, a second input terminal and an output terminal, the first terminal is connected to an external power supply, the second input terminal is connected to a pre-charging circuit, and the output terminal is connected to a switch.

Preferably, the pre-charging circuit includes a low-current charging chip electrically connected between the external power supply and the battery, the low-current charging chip includes a detection pin, and the detection pin outputs a high-level signal when the battery voltage is close to the saturation voltage Give the NOR gate.

Preferably, the fast charging circuit further includes a diode, the anode of the diode is electrically connected to the switch, and the cathode is connected to the battery, so as to prevent battery current from flowing back.

The electronic equipment utilizes the above-mentioned original pre-charging circuit plus the designed fast charging circuit to charge the battery of the electronic equipment, shortening the charging time.

Description of drawings

FIG. 1 is an environment diagram and a specific circuit diagram of an embodiment of an electronic device of the present invention.

Description of main component symbols

electronic equipment 100

battery 10

Fast charging circuit 20

External power supply 30

Precharge circuit 40

Detect pin 41

Switch Q1

Drain D

Source S

Gate G

Diode D1

Comparator U1

NOR gate U2

First resistor R1

Second resistor R2

Reference voltage Vref

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

Please refer to FIG. 1 , which is an environmental diagram and a specific circuit diagram of an embodiment of an electronic device 100 of the present invention.

In this embodiment, the electronic device 100 includes a pre-charging circuit 40 and a fast charging circuit 20 . Both the fast charging circuit 20 and the pre-charging circuit 40 are electrically connected between the external power source 30 and the battery 10 of the electronic device 100 . When the fast charging circuit 20 is working, the fast charging circuit 20 and the pre-charging circuit 40 charge the battery 10 of the electronic device 100 at the same time; In this embodiment, the electronic device 100 may be a portable electronic product such as a smart phone, a tablet computer, and an e-book.

The pre-charging circuit 40 is connected to the external power source 30 for charging the battery 10 of the electronic device 100 . In this embodiment, the pre-charging circuit 40 includes a low-current charging chip, which is electrically connected between the external power supply 30 and the battery 10. The low-current charging chip includes a detection pin 41, and the detection pin 41 detects that the battery 10 When the voltage is not less than the saturation voltage, it outputs a high-level signal to the fast charging circuit 20; when the detection pin 41 detects that the voltage of the battery 10 is lower than the saturation voltage, it outputs a low-level signal to the fast charging circuit 20.

In this embodiment, the fast charging circuit 20 includes a switch Q1 , a comparator U1 and a NOR gate U2 . The switch Q1 is electrically connected between the external power supply 30 and the battery 10 , and is used to control the operation and sleep of the fast charging circuit 20 . In this embodiment, the switch Q1 is an N-type non-metal oxide field effect transistor, the end of the switch Q1 connected to the external power supply 30 is the drain D of the N-type non-metal oxide field effect transistor, and the end of the switch Q1 connected to the battery 10 is The source S of the N-type non-metal oxide field effect transistor, the end connected to the switch Q1 and the NOR gate U2 is the gate G of the N-type non-metal oxide field effect transistor.

The comparator U1 is electrically connected to the battery 10 for comparing the voltage of the battery 10 with the reference voltage Vref. In this embodiment, the comparator U1 includes a positive input terminal, a negative input terminal, and an output terminal, the negative input terminal is electrically connected to the battery 10, the positive input terminal is connected to the reference voltage Vref, and the output terminal is NORed. The gate U2 is electrically connected to the comparator U1 for comparing the voltage of the battery 10 with the reference voltage Vref of the comparator U1, and outputs different level signals according to the comparison result and the level signal output by the pre-charging circuit 40 to control the switch Q1 to be turned on or off.

The NOR gate U2 is electrically connected to the pre-charging circuit 40 , the comparator U1 and the switch Q1 , and is used to output a signal according to the comparison result of the comparator U1 and the level signal output by the pre-charging circuit 40 to control the switch Q1 to be turned on or off. In this embodiment, the NOR gate U2 includes a first input terminal, a second input terminal, and an output terminal, the first input terminal is electrically connected to the output terminal of the comparator U1, and the second input terminal is electrically connected to the pre-charging circuit 40, The output terminal is electrically connected to the gate G of the switch Q1.

In other embodiments, the fast charging circuit 20 further includes a first resistor R1 and a second resistor R2, wherein one end of the first resistor R1 is electrically connected to the positive input end of the comparator U1, and the other end is used to receive the reference voltage Vref. One end of the second resistor R2 is electrically connected to the positive input end of the comparator U1, and the other end is grounded. The first resistor R1 and the second resistor R2 are used to adjust the reference voltage Vref of the comparator U1.

In other implementations, the fast charging circuit 20 further includes a diode D1, the anode of which is electrically connected to the source of the switch Q1, and the cathode is electrically connected to the battery 10, for preventing the battery 10 from flowing back when the battery is not being charged.

The dormancy and operation of the fast charging circuit 20 are controlled by the switch Q1, and the on and off of the switch Q1 is controlled by the level signal output by the NOR gate U2, and the level signal output by the NOR gate U2 is controlled by the pre-charging circuit 40 and The level signal output by comparator U1 is controlled.

The comparator U1 outputs a high level when the voltage of the battery 10 is lower than the reference voltage Vref, and outputs a low level when the voltage of the battery 10 is not lower than the reference voltage Vref. When both the comparator U1 and the pre-charging circuit 40 output a low-level signal, the NOR gate U2 outputs a high-level signal to turn on the switch Q1; when the pre-charging circuit 40 and the comparator U1 output level signals are inconsistent, the NOR The gate U2 outputs a low-level signal to turn off the switch Q1.

In this embodiment, when the switch Q1 is turned on, the fast charging circuit 20 starts to work, and the fast charging circuit 20 and the pre-charging circuit 40 charge the battery 10 of the electronic device 100 at the same time; when the switch Q1 is turned off, the fast charging circuit 20 sleeps , only the battery 10 of the electronic device 100 is charged by the pre-charging circuit 40 alone.

As mentioned above, when the power of the battery 10 of the electronic device 100 is extremely low, such as 10% of the current of the fast charging circuit 20, the voltage of the battery 10 is lower than the reference voltage Vref of the comparator U1, and the output terminal of the comparator U1 will output a high voltage. The level signal is given to the first input terminal of the NOR gate U2, and the precharge circuit 40 outputs a low level signal to the second input terminal of the NOR gate U2 at the same time, and the NOR gate U2 outputs a low level signal, so that the switch Q1 is turned off, Therefore, the fast charging circuit 20 sleeps, and only the pre-charging circuit 40 charges the battery 10 of the electronic device 100 .

After the battery 10 is pre-charged for a period of time, the voltage of the battery 10 gradually increases and is greater than the reference voltage Vref of the comparator U1, and the output interface of the comparator U1 will output a low-level signal to the first input terminal of the NOR gate U2, At the same time, the pre-charging circuit 40 outputs a low-level signal to the second input terminal of the NOR gate U2, and the NOR gate U2 outputs a high-level signal, so that the switch Q1 is turned on, so that the fast charging circuit 20 works, so that the fast charging circuit 20 and the The pre-charging circuit 40 rapidly charges the battery 10 of the electronic device 100 at the same time.

When the voltage of the battery 10 is greater than the saturation voltage, the voltage of the battery 10 is greater than the reference voltage Vref of the comparator U1, and the output interface of the comparator U1 will output a low-level signal to the first input terminal of the NOR gate U2, but the pre-charging circuit 40 Output a high-level signal to the second input terminal of the NOR gate U2, and the NOR gate U2 outputs a low-level signal, so that the switch Q1 is turned off, so that the fast charging circuit 20 is dormant, and only the pre-charging circuit 40 is used for the battery of the electronic device 100. 10 charges.

Thus, in the present invention, when the fast charging circuit 20 is working, the fast charging circuit 20 can accelerate the charging of the battery 10 and shorten the charging time; when the fast charging circuit 20 is in sleep mode, only the pre-charging circuit 40 normally charges the battery 10 to protect the battery 10. out of battery 10.

Claims (7)

1. an electronic equipment, including pre-charge circuit and battery, described pre-charge circuit and external power source It is connected, for the battery of described electronic equipment is charged, it is characterised in that described electronics sets For also including that quick-charging circuit, described quick-charging circuit include:

Switch, is electrically connected between described external power source and described battery；

Comparator, is electrically connected to described battery, for relatively described cell voltage and reference voltage； And

Nor gate, is electrically connected to described pre-charge circuit, described comparator and described switch, is used for The level signal of the comparative result according to comparator and described pre-charge circuit output come output signal with Control switch conduction and cut-off；

When described switch cut-off, described quick-charging circuit disconnects the company with described external power source Connecing, described battery is charged by the most described pre-charge circuit；When described switch conduction, institute Stating the connection of quick-charging circuit conducting and described external power source, described quick-charging circuit is with described Described battery is charged by pre-charge circuit simultaneously, thus shortens the charging interval of described battery.

2. electronic equipment as claimed in claim 1, it is characterised in that described pre-charge circuit is described The voltage of battery gives described nor gate less than output low level during saturation voltage, at the electricity of described battery Pressure gives described nor gate not less than output high level during saturation voltage.

3. electronic equipment as claimed in claim 2, it is characterised in that described comparator is at described battery Voltage gives described nor gate less than output high level during described reference voltage, and at described cell voltage Described nor gate is given not less than output low level during described reference voltage.

4. electronic equipment as claimed in claim 3, it is characterised in that described nor gate is in described comparison When device and described pre-charge circuit all output low level signals, output high level signal make described in open Close conducting, and when described pre-charge circuit and described comparator outputs level signals are inconsistent, defeated Go out low level signal and make described switch cut-off.

5. electronic equipment as claimed in claim 1, it is characterised in that described switch is that N-type is nonmetal Oxidation field effect transistor, one end that described switch is connected with described external power source is the nonmetal oxidation of N-type The drain electrode of field effect transistor, one end that described switch is connected with described battery is N-type nonmetal oxidation field The source electrode of effect pipe, one end that described switch is connected with described nor gate is N-type nonmetal oxidation field Effect tube grid.

6. electronic equipment as claimed in claim 1, it is characterised in that described pre-charge circuit includes low Electric current charging chip, is electrically connected between described external power source and described battery, and described low current fills Electrical chip includes detecting pin, and described detecting pin is detecting described cell voltage not less than saturated During voltage, output high level signal gives described nor gate.

7. electronic equipment as claimed in claim 1, it is characterised in that described quick-charging circuit also wraps Including diode, described diode anode is electrically connected to described switch, and negative electrode is connected with described battery, For preventing the current reflux of described battery.