CN103872715A - Handheld device and power circuit thereof - Google Patents
Handheld device and power circuit thereof Download PDFInfo
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- CN103872715A CN103872715A CN201210541681.3A CN201210541681A CN103872715A CN 103872715 A CN103872715 A CN 103872715A CN 201210541681 A CN201210541681 A CN 201210541681A CN 103872715 A CN103872715 A CN 103872715A
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- electronic switch
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Abstract
The invention relates to a handheld device, comprising a power circuit and a backlight drive unit. The power circuit comprises a power management unit, a comparator, a first electronic switch, a second electronic switch and a battery. When the voltage of an output terminal of the second electronic switch is smaller than the voltage of the battery, the first electronic switch is conducted; the second electronic switch is cut off; and the battery supplies power to the backlight drive unit. When the voltage of the output terminal of the second electronic switch is equal to the voltage of the battery, the first electronic switch is cut off; the second electronic switch is conducted; and the battery management unit supplies power to the backlight drive unit. The handheld device can effectively prevent conditions that the power management unit enters into a low-voltage protection mode when the backlight drive unit generates large current, and further causes handheld device from normal starting, from happening. The invention provides a power supply circuit.
Description
Technical field
The present invention relates to the power circuit of a kind of handheld device and a kind of handheld device.
Background technology
The many PMU (power management unit, Power Management Unit) that adopt of handheld device (as mobile phone) power.After handheld device start, PMU can meet the need for electricity of handheld device.But in the time that handheld device is started shooting, the backlight driving unit of handheld device can produce large electric current.In the time that this large electric current exceedes the maximum current that PMU allows to pass through, PMU starts under-voltage protection pattern, thereby makes the handheld device cannot normal boot-strap.Therefore, generally need to adopt allow the larger PMU of maximum current that passes through, certainly, the cost of the PMU that maximum current that this permission is passed through is larger is also higher.
Summary of the invention
In view of foregoing, be necessary to provide a kind of and can prevent that Power Management Unit from starting the power circuit of under-voltage protection pattern in the time that backlight driving unit produces large electric current.
Also be necessary to provide a kind of handheld device of applying described power circuit.
A kind of power circuit, be used to the backlight driving unit power supply of a handheld device, described power circuit comprises a Power Management Unit, one comparator, one first electronic switch, one second electronic switch, one battery and first to fourth resistance, the input pin of described Power Management Unit is connected with the positive pole of described battery, the minus earth of described battery, the control end of described the first electronic switch is connected with the output of described comparator, the power end of described the first electronic switch is connected with the positive pole of described battery, the output of described the first electronic switch is connected with described backlight driving unit, the control end of described the second electronic switch is connected with the output of described comparator, the power end of described the second electronic switch is connected with the output pin of described Power Management Unit, the output of described the second electronic switch is connected with described backlight driving unit, the in-phase input end of described comparator is connected with the output of described the second electronic switch and is seen through described the second grounding through resistance by described the first resistance, the inverting input of described comparator is connected with the positive pole of described battery and is passed through described the 4th grounding through resistance by described the 3rd resistance, in the time that the voltage of the output of described the second electronic switch is less than the voltage of described battery, the voltage of the in-phase input end of described comparator is less than the voltage of the inverting input of described comparator, output output one first control signal of described comparator, described the first electronic switch conducting, described the second electronic switch cut-off, described battery is given described backlight driving unit power supply by described the first electronic switch, in the time that the voltage of the output of described the second electronic switch equals the voltage of described battery, the voltage of the in-phase input end of described comparator is greater than the voltage of the anti-phase input of described comparator, output output one second control signal of described comparator, described the first electronic switch cut-off, described the second electronic switch conducting, the output pin of described Power Management Unit is given described backlight driving unit power supply by described the second electronic switch.
A kind of handheld device, comprise a power circuit and a backlight driving unit, described power circuit comprises a Power Management Unit, one comparator, one first electronic switch, one second electronic switch, one battery and first to fourth resistance, the input pin of described Power Management Unit is connected with the positive pole of described battery, the minus earth of described battery, the control end of described the first electronic switch is connected with the output of described comparator, the power end of described the first electronic switch is connected with the positive pole of described battery, the output of described the first electronic switch is connected with described backlight driving unit, the control end of described the second electronic switch is connected with the output of described comparator, the power end of described the second electronic switch is connected with the output pin of described Power Management Unit, the output of described the second electronic switch is connected with described backlight driving unit, the in-phase input end of described comparator is connected with the output of described the second electronic switch and is seen through described the second grounding through resistance by described the first resistance, the inverting input of described comparator is connected with the positive pole of described battery and is passed through described the 4th grounding through resistance by described the 3rd resistance, in the time that the voltage of the output of described the second electronic switch is less than the voltage of described battery, the voltage of the in-phase input end of described comparator is less than the voltage of the inverting input of described comparator, output output one first control signal of described comparator, described the first electronic switch conducting, described the second electronic switch cut-off, described battery is given described backlight driving unit power supply by described the first electronic switch, in the time that the voltage of the output of described the second electronic switch equals the voltage of described battery, the voltage of the in-phase input end of described comparator is greater than the voltage of the anti-phase input of described comparator, output output one second control signal of described comparator, described the first electronic switch cut-off, described the second electronic switch conducting, the output pin of described Power Management Unit is given described backlight driving unit power supply by described the second electronic switch.
Handheld device of the present invention and power circuit are by arranging described comparator, described first and second electronic switch and described first to fourth resistance, realize in the time that described backlight driving unit produces large electric current, disconnect the output pin of described Power Management Unit and being connected of described backlight driving unit, and be that described backlight driving unit is powered with described battery.Thereby, effectively avoided described Power Management Unit in the time that described backlight driving unit produces large electric current, to enter under-voltage protection pattern, and then caused the situation that described handheld device cannot normal boot-strap to occur.
Accompanying drawing explanation
In conjunction with preferred embodiments, the present invention is described in further detail with reference to the accompanying drawings:
Fig. 1 is the circuit diagram of the preferred embodiments of handheld device of the present invention.
Main element symbol description
| |
10 |
| |
12 |
| |
20 |
| |
30 |
| |
100 |
| Battery | BAT |
| Electric capacity | C |
| Metal-oxide-semiconductor | Q1、Q2 |
| Resistance | R1-R6 |
| Comparator | U |
Following embodiment further illustrates the present invention in connection with above-mentioned accompanying drawing.
Embodiment
Please refer to Fig. 1, the preferred embodiments of handheld device 100 of the present invention comprises a power circuit 10 and a backlight driving unit 20.Described power circuit 10 is powered for described backlight driving unit 20.In the present embodiment, described handheld device 100 can be mobile phone or personal digital assistant (personal digital assistant, PAD).Described power circuit 10 is also other element power supply in described handheld device 100, to maintain the normal work of described handheld device 100.
Described power circuit 10 comprises a PMU (power management unit, Power Management Unit) 12, a battery BAT, a comparator U, a capacitor C, the two metal-oxide-semiconductor Q1 as electronic switch and Q2 and six resistance R 1-R6.Described PMU 12 comprises one first input pin I1, one second input pin I2 and an output pin IPSOUT.Described the first input pin I1 is for being connected with a charging device 30.Described the second input pin I2 is connected with the positive pole of described battery BAT.The minus earth of described battery BAT.The grid of described metal-oxide-semiconductor Q1 is connected with the output of described comparator U by described resistance R 5.The drain electrode of described metal-oxide-semiconductor Q1 is connected with the positive pole of described battery BAT.The source electrode of described metal-oxide-semiconductor Q1 is connected with described backlight driving unit 20.The grid of described metal-oxide-semiconductor Q2 is connected with the output of described comparator U by described resistance R 6.The drain electrode of described metal-oxide-semiconductor Q2 is connected with the output pin IPSOUT of described PMU 12.The source electrode of described metal-oxide-semiconductor Q2 is connected with described backlight driving unit 20.The in-phase input end of described comparator U is connected with the source electrode of described metal-oxide-semiconductor Q2 by described resistance R 1, and by described resistance R 2 ground connection, also by described capacitor C ground connection.The inverting input of described comparator U is connected with the positive pole of described battery BAT by described resistance R 3, and by described resistance R 4 ground connection.
In the present embodiment, described metal-oxide-semiconductor Q1 is a PMOS pipe, and described metal-oxide-semiconductor Q2 is a NMOS pipe.The resistance r1 of described resistance R 1 equates with the resistance r3 of described resistance R 3, and the resistance r2 of described resistance R 2 is greater than the resistance r4 of described resistance R 4.The voltage of described battery BAT is V
bAT, the voltage of the source electrode of described metal-oxide-semiconductor Q2 is V
0, the voltage of the in-phase input end of described comparator U is V
1, the voltage of the inverting input of described comparator U is V
2.V
1meet formula (1) V
1=V
0r2/ (r1+r2), V
2meet formula (2) V
2=V
bATr4/ (r3+r4).Described battery BAT is lithium battery.Described charging device 30 is a charger.In other embodiments, described metal-oxide-semiconductor Q1 is replaceable has the switch of identical function for positive-negative-positive triode and other.Described metal-oxide-semiconductor Q2 is replaceable for NPN type triode and other have the switch of identical function, and described backlight driving unit 20 can be other power consumption unit that can produce large electric current in described handheld device 100 in the time starting.
In the time that the first input pin I1 of described PMU 12 is not connected with described charging device 30, the voltage that described PMU 12 utilizes described battery BAT to provide is that described handheld device 100 is powered.In the time that the first input pin I1 of described PMU 12 is connected with described charging device 30, the voltage that described PMU 12 utilizes described charging device 30 to provide is that described handheld device 100 is powered or is described battery BAT charging.
In the time that described handheld device 100 is started shooting, the output pin IPSOUT of described PMU 12 is that described backlight driving unit 20 is powered by described metal-oxide-semiconductor Q2.When the moment that described backlight driving unit 20 starts, described backlight driving unit 20 can become to produce large electric current.The current value of described large electric current is the downward trend again that first rises, and therefore, in the time that described backlight driving unit 20 has just started, the current value of described large electric current does not arrive its peak value, can not exceed described PMU 12 yet and allow the maximum current passing through.Now, described large electric current flows into described PMU 12 by described metal-oxide-semiconductor Q2, and described PMU 12 can not start under-voltage protection pattern.
Because described PMU 12 self exists small resistor, in the time that described backlight driving unit 20 does not produce large electric current, 12 points of described PMU voltage minimum, negligible.But the large electric current of having produced in the time that described backlight driving unit 20 has just started flows into after described PMU 12, described PMU 12 will get most of voltage that described charging device 30 or described battery BAT provide, thereby makes the voltage V of the source electrode of described metal-oxide-semiconductor Q2
0dragged down.Now, the voltage V of the source electrode of described metal-oxide-semiconductor Q2
0be less than the voltage V of described battery BAT
bAT, known according to above-mentioned formula (1) and formula (2), the voltage V of the in-phase input end of described comparator U
1be less than the voltage V of the inverting input of described comparator U
2, the output of described comparator U is exported a low level signal, described metal-oxide-semiconductor Q1 conducting, and described metal-oxide-semiconductor Q2 cut-off, described battery BAT is that described backlight driving unit 20 is powered by described metal-oxide-semiconductor Q1.
When described battery BAT is described backlight driving unit 20 while powering by described metal-oxide-semiconductor Q1, the voltage V of the source electrode of described metal-oxide-semiconductor Q2
0equal the voltage V of described battery BAT
bAT, known according to above-mentioned formula (1) and formula (2), the voltage V of the in-phase input end of described comparator U
1be greater than the voltage V of the inverting input of described comparator U
2, the output of described comparator U is exported a high level signal, described metal-oxide-semiconductor Q1 cut-off, and described metal-oxide-semiconductor Q2 conducting, the output pin IPSOUT of described PMU 12 is that described backlight driving unit 20 is powered by described metal-oxide-semiconductor Q2.Because the time that described backlight driving unit 20 starts is very of short duration, and after described backlight driving unit 20 starts, described large current vanishes.Therefore, when described metal-oxide-semiconductor Q2 is when cut-off becomes conducting, described backlight driving unit 20 has started, and described large current vanishes disappears.After this, described metal-oxide-semiconductor Q2 will maintain conducting state, and the output pin IPSOUT of described PMU 12 is that described backlight driving unit 20 is powered by described metal-oxide-semiconductor Q2.
Claims (10)
1. a power circuit, be used to the backlight driving unit power supply of a handheld device, described power circuit comprises a Power Management Unit, one comparator, one first electronic switch, one second electronic switch, one battery and first to fourth resistance, the input pin of described Power Management Unit is connected with the positive pole of described battery, the minus earth of described battery, the control end of described the first electronic switch is connected with the output of described comparator, the power end of described the first electronic switch is connected with the positive pole of described battery, the output of described the first electronic switch is connected with described backlight driving unit, the control end of described the second electronic switch is connected with the output of described comparator, the power end of described the second electronic switch is connected with the output pin of described Power Management Unit, the output of described the second electronic switch is connected with described backlight driving unit, the in-phase input end of described comparator is connected with the output of described the second electronic switch and is seen through described the second grounding through resistance by described the first resistance, the inverting input of described comparator is connected with the positive pole of described battery and is passed through described the 4th grounding through resistance by described the 3rd resistance, in the time that the voltage of the output of described the second electronic switch is less than the voltage of described battery, the voltage of the in-phase input end of described comparator is less than the voltage of the inverting input of described comparator, output output one first control signal of described comparator, described the first electronic switch conducting, described the second electronic switch cut-off, described battery is given described backlight driving unit power supply by described the first electronic switch, in the time that the voltage of the output of described the second electronic switch equals the voltage of described battery, the voltage of the in-phase input end of described comparator is greater than the voltage of the anti-phase input of described comparator, output output one second control signal of described comparator, described the first electronic switch cut-off, described the second electronic switch conducting, the output pin of described Power Management Unit is given described backlight driving unit power supply by described the second electronic switch.
2. power circuit as claimed in claim 1, is characterized in that: the resistance of described the first resistance equates with the resistance of described the 3rd resistance, and the resistance of described the second resistance is greater than the resistance of described the 4th resistance.
3. power circuit as claimed in claim 1, it is characterized in that: described power circuit also comprises an electric capacity, one the 5th resistance and one the 6th resistance, the in-phase input end of described comparator is by described capacity earth, and the output of described comparator is connected with the control end of described the first electronic switch and is passed through described the 6th resistance by described the 5th resistance and is connected with the control end of described the second electronic switch.
4. power circuit as claimed in claim 1, is characterized in that: described the first control signal is a low level signal, and described the second control signal is a high level signal.
5. power circuit as claimed in claim 4, it is characterized in that: described the first electronic switch is a PMOS field effect transistor, control end, power end and the output of described the first electronic switch corresponds respectively to grid, drain electrode and the source electrode of PMOS field effect transistor, described the second electronic switch is a NMOS field effect transistor, and control end, power end and the output of described the second electronic switch corresponds respectively to grid, drain electrode and the source electrode of NMOS field effect transistor.
6. a handheld device, comprise a power circuit and a backlight driving unit, described power circuit comprises a Power Management Unit, one comparator, one first electronic switch, one second electronic switch, one battery and first to fourth resistance, the input pin of described Power Management Unit is connected with the positive pole of described battery, the minus earth of described battery, the control end of described the first electronic switch is connected with the output of described comparator, the power end of described the first electronic switch is connected with the positive pole of described battery, the output of described the first electronic switch is connected with described backlight driving unit, the control end of described the second electronic switch is connected with the output of described comparator, the power end of described the second electronic switch is connected with the output pin of described Power Management Unit, the output of described the second electronic switch is connected with described backlight driving unit, the in-phase input end of described comparator is connected with the output of described the second electronic switch and is seen through described the second grounding through resistance by described the first resistance, the inverting input of described comparator is connected with the positive pole of described battery and is passed through described the 4th grounding through resistance by described the 3rd resistance, in the time that the voltage of the output of described the second electronic switch is less than the voltage of described battery, the voltage of the in-phase input end of described comparator is less than the voltage of the inverting input of described comparator, output output one first control signal of described comparator, described the first electronic switch conducting, described the second electronic switch cut-off, described battery is given described backlight driving unit power supply by described the first electronic switch, in the time that the voltage of the output of described the second electronic switch equals the voltage of described battery, the voltage of the in-phase input end of described comparator is greater than the voltage of the anti-phase input of described comparator, output output one second control signal of described comparator, described the first electronic switch cut-off, described the second electronic switch conducting, the output pin of described Power Management Unit is given described backlight driving unit power supply by described the second electronic switch.
7. handheld device as claimed in claim 6, is characterized in that: the resistance of described the first resistance equates with the resistance of described the 3rd resistance, and the resistance of described the second resistance is greater than the resistance of described the 4th resistance.
8. handheld device as claimed in claim 6, it is characterized in that: described power circuit also comprises an electric capacity, one the 5th resistance and one the 6th resistance, the in-phase input end of described comparator is by described capacity earth, and the output of described comparator is connected with the control end of described the first electronic switch and is passed through described the 6th resistance by described the 5th resistance and is connected with the control end of described the second electronic switch.
9. handheld device as claimed in claim 6, is characterized in that: described the first control signal is a low level signal, and described the second control signal is a high level signal.
10. handheld device as claimed in claim 9, it is characterized in that: described the first electronic switch is a PMOS field effect transistor, control end, power end and the output of described the first electronic switch corresponds respectively to grid, drain electrode and the source electrode of PMOS field effect transistor, described the second electronic switch is a NMOS field effect transistor, and control end, power end and the output of described the second electronic switch corresponds respectively to grid, drain electrode and the source electrode of NMOS field effect transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210541681.3A CN103872715A (en) | 2012-12-14 | 2012-12-14 | Handheld device and power circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210541681.3A CN103872715A (en) | 2012-12-14 | 2012-12-14 | Handheld device and power circuit thereof |
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| Publication Number | Publication Date |
|---|---|
| CN103872715A true CN103872715A (en) | 2014-06-18 |
Family
ID=50910973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210541681.3A Pending CN103872715A (en) | 2012-12-14 | 2012-12-14 | Handheld device and power circuit thereof |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104485714A (en) * | 2014-12-28 | 2015-04-01 | 湖南森泰能源科技股份有限公司 | Power management control device and control method thereof |
| CN104753145A (en) * | 2015-04-20 | 2015-07-01 | 宁波萨瑞通讯有限公司 | Self-locking power switch |
| CN105576761A (en) * | 2016-01-22 | 2016-05-11 | 江苏中海昇物联科技有限公司 | Multi-power supply circuit of engineering equipment monitoring device and engineering equipment monitoring device |
| CN108258904A (en) * | 2017-12-01 | 2018-07-06 | 珠海格力电器股份有限公司 | DC power supply and its method of supplying power to |
| CN111316528A (en) * | 2018-07-27 | 2020-06-19 | 华为技术有限公司 | Power supply circuit of terminal equipment, terminal equipment and power supply method |
-
2012
- 2012-12-14 CN CN201210541681.3A patent/CN103872715A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104485714A (en) * | 2014-12-28 | 2015-04-01 | 湖南森泰能源科技股份有限公司 | Power management control device and control method thereof |
| CN104485714B (en) * | 2014-12-28 | 2016-08-24 | 湖南金杯新能源发展有限公司 | Device for managing and controlling electrical source and control method thereof |
| CN104753145A (en) * | 2015-04-20 | 2015-07-01 | 宁波萨瑞通讯有限公司 | Self-locking power switch |
| CN104753145B (en) * | 2015-04-20 | 2017-04-05 | 宁波萨瑞通讯有限公司 | A kind of on and off switch with auto-lock function |
| CN105576761A (en) * | 2016-01-22 | 2016-05-11 | 江苏中海昇物联科技有限公司 | Multi-power supply circuit of engineering equipment monitoring device and engineering equipment monitoring device |
| CN105576761B (en) * | 2016-01-22 | 2018-12-04 | 江苏中海昇物联科技有限公司 | The multiple feed circuit and engineering equipment monitoring device of engineering equipment monitoring device |
| CN108258904A (en) * | 2017-12-01 | 2018-07-06 | 珠海格力电器股份有限公司 | DC power supply and its method of supplying power to |
| CN111316528A (en) * | 2018-07-27 | 2020-06-19 | 华为技术有限公司 | Power supply circuit of terminal equipment, terminal equipment and power supply method |
| CN111316528B (en) * | 2018-07-27 | 2022-11-01 | 荣耀终端有限公司 | Power supply circuit of terminal equipment, terminal equipment and power supply method |
| CN115632454A (en) * | 2018-07-27 | 2023-01-20 | 荣耀终端有限公司 | Power supply circuit of terminal equipment, terminal equipment and power supply method |
| CN115632454B (en) * | 2018-07-27 | 2023-10-13 | 荣耀终端有限公司 | Power supply circuit of terminal equipment, terminal equipment and power supply method |
| US11949272B2 (en) | 2018-07-27 | 2024-04-02 | Honor Device Co., Ltd. | Power supply circuit of terminal device, terminal device, and power supply method |
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Application publication date: 20140618 |