CN102222942A - Power supply circuit and charging method for electronic equipment - Google Patents

Abstract

The invention provides a power supply circuit and a charging method for electronic equipment, relating to the field of charging technology. The power supply circuit comprises a charger, a charging chip, a battery and a power management unit, wherein the charger is connected to the charging chip in a pluggable way; the battery can be charged by the charging chip; the battery can supply power to the electronic equipment by the power management unit; the circuit further comprises a voltage stabilizer, a switch and a control unit; the voltage stabilizer is connected to the input terminal of the charging chip and the input terminal of the power management unit; the switch is connected between the output terminal of the charging chip and the input terminal of the power management unit; one end of the control unit is connected to the input terminal of the charging chip; the other end of the control unit is connected to the switch; when the control unit detects that the charger is connected to the charging chip, the control switch is in an open circuit state; and when the control unit detects that the input terminal of the charging chip is not connected to the charger, the control switch is in a conducted state.

Description

The power supply circuits of electronic equipment and charging method

Technical field

The present invention relates to charging technique, relate in particular to a kind of electronic device power supply circuit and charging method.

Background technology

Present electronic equipment (MP3, MP4, PDA, mobile phone etc.) all is by battery powered.Yet, after the battery over-discharge can, when promptly cell voltage is lower than the start voltage of electronic equipment, electronic equipment can't be started shooting, even plug charger, also needs the precharge of a period of time, after promptly will waiting cell voltage to reach the start voltage of electronic equipment, electronic equipment could be started shooting.

In the prior art, the power supply circuits of electronic equipment as shown in Figure 1, described power supply circuits comprise charger, charging chip, rechargeable battery and Power Management Unit.Charger links to each other with the input of charging chip, and the output of charging chip links to each other with battery, links to each other with the input of Power Management Unit simultaneously.

After the rechargeable battery over-discharge can; charged battery voltage is lower than electronic equipment start voltage; promptly insert charger; Power Management Unit determines charged battery voltage when being lower than electronic equipment start voltage, can steady operation and protection rechargeable battery in order to guarantee electronic equipment, and Power Management Unit can not given power electronic equipment; electronic equipment can't be started shooting; charger only is the rechargeable battery charging by charging chip, and rechargeable battery is in pre-charge state.

When the voltage of rechargeable battery greater than the electronic equipment voltage of starting shooting, when promptly Power Management Unit determined charged battery voltage greater than electronic equipment start voltage, the output output voltage of Power Management Unit was given electronic equipment, electronic equipment can normal boot-strap.At this moment, charger is by charging chip, not only will be for rechargeable battery charge, but also to be power electronic equipment, rechargeable battery is in normal charging condition.

In sum, if the rechargeable battery over-discharge can of electronic equipment, in charging process, must carry out precharge, under the rechargeable battery pre-charge state, electronic equipment can't use by normal boot-strap, like this, is not having under the situation of reserve battery, electronic equipment can not be used for a long time because of precharge, make troubles to the user.

Summary of the invention

The invention provides a kind of power supply circuits and charging method of electronic equipment, with after must carrying out precharge after the battery over-discharge can that overcomes electronic equipment and making the start voltage of its voltage greater than electronic equipment, the shortcoming that electronic equipment could normal boot-strap.

For achieving the above object, the invention provides following technical scheme:

A kind of power supply circuits of electronic equipment comprise charger, charging chip, battery, Power Management Unit; Wherein charger with can plug the ground mode be connected to charging chip, be battery charge via charging chip, battery via Power Management Unit to power electronic equipment; Described circuit further comprises pressurizer, switch and control unit, wherein,

Pressurizer is connected to the input of charging chip and the input of Power Management Unit;

Switch is connected between the input of charging chip output and Power Management Unit;

Control unit one end is connected to the input of charging chip, and the other end is connected to switch; Be connected to charging chip when control unit detects charger, then control switch is in off state, does not connect charger when control unit detects the charging chip input, and then control switch is in the state of conducting.

As a further improvement on the present invention, when charger is not connected to charging chip, described power supply circuits comprise one first current supply circuit, and described first current supply circuit comprises battery, switch and Power Management Unit, battery directly via Power Management Unit to power electronic equipment.

As a further improvement on the present invention, when charger is connected to charging chip, described power supply circuits comprise a charge circuit and a direct current supply circuit, and two loops are independent respectively, wherein charge circuit directly is a battery charge, and directly current supply circuit directly provides power supply to supply with electronic equipment via Power Management Unit.

As a further improvement on the present invention, described charging circuit comprises charger, charging chip and battery, and charger charges the battery via charging chip.

As a further improvement on the present invention, described direct current supply circuit comprises charger, pressurizer, Power Management Unit, and wherein charger is directly given power electronic equipment by pressurizer, Power Management Unit.

Also a kind of charging method that adopts described power supply circuits of the present invention, described method comprises the steps:

Charger is connected to charging chip;

The control unit control switch is in off state;

To battery charge, simultaneously, charger provides power supply by pressurizer to charger, offers electronic equipment via Power Management Unit by charging chip.

The present invention is under the state of battery over-discharge can, insert charger, be that electronic equipment is directly powered then by direct current supply circuit, need not to wait for battery pre-charging, avoided after the rechargeable battery over-discharge can of electronic equipment under the rechargeable battery pre-charge state situation that electronic equipment can't normal boot-strap uses.Simultaneously, when inserting charger, directly current supply circuit is separate with the charge circuit that is battery charge, and promptly charging current can not shunted, and has effectively accelerated the charging rate of battery.

Description of drawings

Fig. 1 is the schematic diagram of electronic device power supply circuit in the prior art.

Fig. 2 is the schematic diagram of electronic device power supply circuit among the present invention.

Fig. 3 is another schematic diagram of electronic device power supply circuit among the present invention.

Embodiment

Below in conjunction with accompanying drawing electronic device power supply circuit of the present invention and charging method are described in further detail.

See also Fig. 2, electronic device power supply circuit of the present invention comprisescharger 10,charging chip 12,battery 13,switch 14,Power Management Unit 15,control unit 16, pressurizer 17 andelectronic equipment 18.

The output ofcharger 10 is connected tocharging chip 12 in pluggable mode, forcharging chip 12 provides power supply.The output ofcharger 10 is connected to the input of pressurizer 17 simultaneously, and the output of pressurizer 17 is connected to the input of Power Management Unit 15.The output ofcharging chip 12 is connected tobattery 13 and switch 14 simultaneously, and charge power supply is offeredbattery 13 and switch 14.Switch 14 is connected with the input of Power Management Unit 15.PowerManagement Unit 15 is connected toelectronic equipment 18, when detecting input voltage greater than the start voltage ofelectronic equipment 18, then exports supply power voltage and gives electronic equipment 18.Control unit 16control switchs 14 switch between conducting state or off state.

One, whencharger 10 is not connected tocharging chip 12,control unit 16control switchs 14 are in conducting state, and promptlybattery 13,switch 14,Power Management Unit 14 andelectronic equipment 18 constitute power supply circuits.

Battery 13 provides charge power supply viaPower Management Unit 15 to electronic equipment 18.Power Management Unit 15 real-time monitoring battery 13 voltages, ifbattery 13 voltages greater than the start voltage ofelectronic equipment 18,Power Management Unit 15 output supply power voltages are givenelectronic equipment 18; Ifrechargeable battery 13 voltages are less than the start voltage ofelectronic equipment 18,15 of Power Management Unit stop to export supply power voltage and giveelectronic equipment 18, andelectronic equipment 18 shutdown maybe can't be started shooting.

Two, whencharger 10 is connected tocharging chip 12,control unit 16control switchs 14 are in off state, comprise 2 circuit loops: charge circuit is to be made ofcharger 10,charging chip 12 andbattery 13; Directly current supply circuit is to be made ofcharger 10, pressurizer 17,Power Management Unit 15 andelectronic equipment 18.

The situation thatcharger 10 is connected to chargingchip 12 has three kinds: the firstth, andelectronic equipment 18 can't be powered because ofbattery 13 and be shut down; The secondth, the electric weight ofbattery 13 storages is not enough butelectronic equipment 18 also is in open state; The 3rd iselectronic equipment 18 shutdown, and the electric weight ofbattery 13 storages is also not enough.

1, shut down because ofbattery 13 electric weight are not enough whenelectronic equipment 18, this moment,battery 13 voltages were less than the start voltage ofelectronic equipment 18.

Whencharger 10 was connected to chargingchip 12, directlycharger 10 was givenPower Management Unit 15 by pressurizer 17 output supply power voltages in the current supply circuit, andPower Management Unit 15 output supply power voltages are givenelectronic equipment 18, butelectronic equipment 18 normal boot-straps.Simultaneously,charger 10 directly givesbattery 13 chargings bycharging chip 12 in the charge circuit.Becauseswitch 14 is in off state, charging current can not shunted toelectronic equipment 18, and promptly the charging current ofbattery 13 can be guaranteed, and therefore can reduce the charging interval.

2, whenbattery 13 voltages during greater than the start voltage ofelectronic equipment 18 andelectronic equipment 18 be in open state.

Be connected to the moment ofcharging chip 12 when charger 10, be thatcharger 10 and battery givePower Management Unit 15 power supplies simultaneously, the voltage that the voltage that Power ManagementUnit judgement charger 10 is exported via pressurizer 17 provides greater thanbattery 13, then switch to charger 10 rapidly by pressurizer 17 power supplies, and makeswitch 14 be in off state.At this moment, directlycharger 10 is givenPower Management Unit 15 by pressurizer 17 output supply power voltages in the current supply circuit, forelectronic equipment 18 provides supply power voltage.Simultaneously,charger 10 directly givesrechargeable battery 13 chargings bycharging chip 12 in the charge circuit.Becauseswitch 14 is in off state, charging current can not shunted toelectronic equipment 18, and promptly the charging current ofbattery 13 can be guaranteed, and therefore can reduce the charging interval.

3, whenbattery 13 voltages during greater than the start voltage ofelectronic equipment 18 andelectronic equipment 18 be in off-mode.

Whencharger 10 is connected tocharging chip 12, directlycharger 10 is givenPower Management Unit 15 by pressurizer 17 output supply power voltages in the current supply circuit, because not start ofelectronic equipment 18,15 of Power Management Unit can not exported supply power voltage and give electronic equipment 18.Simultaneously,charger 10 givesrechargeable battery 13 chargings bycharging chip 12, and at this moment,switch 14 is in off state, and the charging current ofbattery 13 can be guaranteed, and therefore can reduce the charging interval.

The present invention is based on above-mentioned power supply circuits a kind of new charging method also is provided, described method comprises the steps:

Charger is connected to charging chip;

The control unit control switch is in off state;

To battery charge, simultaneously, charger provides power supply by pressurizer to charger, offers electronic equipment via Power Management Unit by charging chip.

See also Fig. 3, be preferred embodiment of the present invention, pressurizer 17 adopts LDO (low dropoutregulator, low pressure difference linear voltage regulator), andswitch 14 adopts the P channel MOS tube.

In preferred embodiment of the present invention, the physical circuit ofcontrol unit 16 comprises capacitor C 1, diode D2 and resistance R 1, R2.Capacitor C 1 and resistance R 2 parallel circuitss one end are connected to the grid of P channel MOS tube, other end ground connection; Circuit one end of resistance R 1 and diode D2 parallel connection is connected to the grid of P channel MOS tube, and the other end is connected to the output of charger 10.Wherein the negative electrode of diode D2 links to each other with the charger output, and the anode of diode D2 links to each other with the grid of P channel MOS tube.

The positive pole of capacitor C 2 links to each other with Power Management Unit input VBAT, and the negative pole of capacitor C 2 links to each other with ground.

When not inserting charger, the grid of P channel MOS tube V1 is dragged down by R2, so metal-oxide-semiconductor V1 conducting.Rechargeable battery provides electric current I 4, and through P channel MOS tube V1, promptly I4=I2=I6 offers Power Management Unit and uses, and promptly VSYS=VBAT-VDS because V1 VDS under the saturation conduction state is very little, can ignore, and the Power Management Unit input voltage approximates VBAT.

Insert charger, the G utmost point (grid) of P channel MOS tube V1 is drawn high, and P channel MOS tube V1 is in off state.

When cell voltage is lower than electronic equipment start voltage, insert charger, LDO output 4.2V power supply is given Power Management Unit, and Power Management Unit output supply power voltage is given electronic equipment, and electronic equipment can normal boot-strap, can not be subjected to the influence of the voltage of battery own.Simultaneously, charger charges the battery by charging chip, i.e. I3=I1.Because the shutoff of V1, and VSYS＞VBAT, so VSYS is cut off to path between the VBAT.When therefore having realized that charging chip charges to rechargeable battery, can not shunt a part and give power electronic equipment from charging current, promptly the charging current of battery can be guaranteed, and therefore can reduce the charging interval.

When cell voltage is higher than electronic equipment start voltage and electronic equipment is in off-mode, insert charger, LDO output this moment 4.2V power supply is given Power Management Unit, becauseelectronic equipment 18 is in off-mode, Power Management Unit does not have output voltage and gives electronic equipment.Simultaneously charger charges to rechargeable battery by charging chip, promptly can think I3=I1.Because the shutoff of V1, and VSYS＞VBAT, so VSYS is cut off to path between the VBAT.When therefore having realized that charging chip charges to rechargeable battery, can not shunt a part and give power electronic equipment from charging current, promptly the charging current of battery can be guaranteed, and therefore can reduce the charging interval.

When cell voltage is higher than electronic equipment start voltage and electronic equipment place open state, when inserting charger, power electronic equipment can switch, and promptly gives power electronic equipment from being switched to by LDO to power electronic equipment by battery.At this moment, under the keeping of C1, metal-oxide-semiconductor V1 continues conducting, and LDO output 4.2V power supply is higher than the VBAT power supply, so Power Management Unit is automatically from the LDO power taking, i.e. I6=0, I2=I5.Along with charger charges to C1 by R1, the last voltage of C1 raises gradually, and after time second, the C1 charging is finished through about R1*C1, and metal-oxide-semiconductor V1 grid uprises, and V1 turn-offs.When pulling out charger, power electronic equipment also can switch, and promptly gives power electronic equipment from being switched to by battery to power electronic equipment by D1.At this moment, C1 discharges rapidly by diode D2, metal-oxide-semiconductor V1 grid step-down, and metal-oxide-semiconductor V1 opens, and connects the path of VBAT to the Power Management Unit power supply.This switching time is very short, and little of nanosecond, the capacitor C 2 that is connected between transfer period on the VSYS provides transient current for system.In order to guarantee power supply seamless switching, system's power supply steadily, require R1*C1 much larger than LDO/DC-DC power supply output delay time, C2 is generally tens microfarads and gets final product.

More than by embodiment the present invention is had been described in detail, but these are not to be construed as limiting the invention.Protection scope of the present invention is not exceeded with above-mentioned execution mode, as long as the equivalence that those of ordinary skills do according to disclosed content is modified or changed, all should include the protection range of putting down in writing in claims in.

Claims (6)

1. the power supply circuits of an electronic equipment comprise charger, charging chip, battery, Power Management Unit; Wherein charger with can plug the ground mode be connected to charging chip, be battery charge via charging chip, battery via Power Management Unit to power electronic equipment; It is characterized in that: described power supply circuits further comprise pressurizer, switch and control unit, wherein,

Pressurizer is connected to the input of charging chip and the input of Power Management Unit;

Switch is connected between the input of charging chip output and Power Management Unit;

Control unit one end is connected to the input of charging chip, and the other end is connected to switch; Be connected to charging chip when control unit detects charger, then control switch is in off state, does not connect charger when control unit detects the charging chip input, and then control switch is in the state of conducting.

2. the power supply circuits of electronic equipment as claimed in claim 1, it is characterized in that: when charger is not connected to charging chip, described power supply circuits comprise one first current supply circuit, described first current supply circuit comprises battery, switch and Power Management Unit, battery directly via Power Management Unit to power electronic equipment.

3. the power supply circuits of electronic equipment as claimed in claim 1, it is characterized in that: when charger is connected to charging chip, described power supply circuits comprise a charge circuit and a direct current supply circuit, and two loops are independent respectively, wherein charge circuit directly is a battery charge, and directly current supply circuit directly provides power supply to supply with electronic equipment via Power Management Unit.

4. the power supply circuits of electronic equipment as claimed in claim 3, it is characterized in that: described charging circuit comprises charger, charging chip and battery, and charger charges the battery via charging chip.

5. the power supply circuits of electronic equipment as claimed in claim 3, it is characterized in that: described direct current supply circuit comprises charger, pressurizer, Power Management Unit, wherein charger is directly given power electronic equipment by pressurizer, Power Management Unit.

6. one kind is adopted the charging method of power supply circuits according to claim 1, and it is characterized in that: described method comprises the steps:

Charger is connected to charging chip;

The control unit control switch is in off state;

To battery charge, simultaneously, charger provides power supply by pressurizer to charger, offers electronic equipment via Power Management Unit by charging chip.

Images