CN101995896A - LDO (Low Drop Output) circuit for mobile terminal - Google Patents
LDO (Low Drop Output) circuit for mobile terminal Download PDFInfo
- Publication number
- CN101995896A CN101995896A CN2010105395644A CN201010539564A CN101995896A CN 101995896 A CN101995896 A CN 101995896A CN 2010105395644 A CN2010105395644 A CN 2010105395644A CN 201010539564 A CN201010539564 A CN 201010539564A CN 101995896 A CN101995896 A CN 101995896A
- Authority
- CN
- China
- Prior art keywords
- ldo circuit
- mobile terminal
- operational amplifier
- oxide
- ldo
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses an LDO circuit for a mobile terminal which comprises an operational amplifier, an MOS (Metal Oxide Semiconductor) pipe and a voltage regulation module, wherein the reverse input end of the operational amplifier is connected with a PMIC (Power Management Integrated Circuit) module of the mobile terminal, the positive input end of the operational amplifier is connected with the output port the LDO circuit through the voltage regulation module, the output end of the computing amplifier is connected with the grid of the MOS pipe, the drain of the MOS pipe is connected with the output port of the LDO circuit, and the source electrode of the MOS pipe is connected with the power supply. A feedback circuit is formed through the operational amplifier and the MOS pipe, and the LDO terminal outputs a voltage required by the working of a mobile phone functional chip by setting the resistance of the voltage regulation module. The LDO circuit provided by the embodiment of the invention has few electronic components; and the electronic components are inexpensive, thus the cost of the mobile terminal is reduced, and the mobile terminal competitiveness in the market is increased.
Description
Technical field
The present invention relates to communication technical field, particularly a kind of used for mobile terminal LDO circuit.
Background technology
Cell-phone function is more and more, the power supply that various functions need also emerges in an endless stream, the voltage that needs 1.8V such as the functional chip that has, the functional chip that has needs the voltage of 3.3V, thereby can realize that cell voltage arrives the conversion of needed voltage through LDO device (low dropout regulator, low pressure difference linear voltage regulator) commonly used.
Traditional way is to increase the LDO chip to arrive the purpose that changes output voltage in mobile phone, but adopts the LDO chip can make the cost of mobile phone higher, has reduced the competitive power of mobile phone on market.
Thereby prior art is still waiting to improve and improve.
Summary of the invention
In view of above-mentioned the deficiencies in the prior art part, the object of the present invention is to provide a kind of used for mobile terminal LDO circuit, the required voltage of various functional chip work in the portable terminal can be provided.
In order to achieve the above object, the present invention has taked following technical scheme:
A kind of used for mobile terminal LDO circuit wherein, comprises operational amplifier, metal-oxide-semiconductor and Voltage Regulator Module; The reverse input end of described operational amplifier is connected with the PMIC module of portable terminal, and positive input is by the output port of Voltage Regulator Module connection LDO circuit, and the output terminal of operational amplifier connects the grid level of described metal-oxide-semiconductor; The drain electrode of described metal-oxide-semiconductor connects the output port of LDO circuit, and the source electrode of metal-oxide-semiconductor connects power supply.
Described used for mobile terminal LDO circuit, wherein, described Voltage Regulator Module comprises first resistance and second resistance; Described first resistance string is associated between the output port of the positive input of operational amplifier and LDO circuit, an end concatenation operation amplifier positive input of second resistance, other end ground connection.
Described used for mobile terminal LDO circuit wherein, also comprises first electric capacity, the reverse input end of an end concatenation operation amplifier of described first electric capacity, other end ground connection.
Described used for mobile terminal LDO circuit wherein, also comprises second electric capacity, and an end of described second electric capacity connects the drain electrode of metal-oxide-semiconductor, other end ground connection.
Described used for mobile terminal LDO circuit, wherein, described metal-oxide-semiconductor is the P channel MOS tube.
Described used for mobile terminal LDO circuit, wherein, described portable terminal is a mobile phone.
A kind of used for mobile terminal LDO circuit provided by the invention, it comprises operational amplifier, metal-oxide-semiconductor and Voltage Regulator Module, constitute feedback circuit by operational amplifier and metal-oxide-semiconductor,, make the required voltage of LDO circuit output cell-phone function chip operation then by the resistance of Voltage Regulator Module is set.The electronic component that the LDO circuit that the embodiment of the invention provides adopts is few, and the low price of the electron device that uses, and has reduced the cost of portable terminal, has increased the competitive power of portable terminal on market.
Description of drawings
The circuit block diagram of the LDO circuit that Fig. 1 provides for the embodiment of the invention.
The circuit theory diagrams of the LDO circuit that Fig. 2 provides for the embodiment of the invention.
Embodiment
The invention provides a kind of used for mobile terminal LDO circuit, clearer, clear and definite for making purpose of the present invention, technical scheme and effect, below with reference to accompanying drawing and give an actual example that the present invention is described in more detail.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
The LDO circuit that the embodiment of the invention provides be arranged on the circuit board of mobile phone with mobile phone in PMIC module 110(project management integrate circuit, power management chip) connects, be used for providing stable power voltage to the functional chip of mobile phone.
Wherein, the general power management chip of PMIC module 110 for using in the existing mobile phone, the voltage of its output is the reference voltage of whole cell phone system power supply, see also Fig. 1 and Fig. 2, described LDO circuit comprises operational amplifier U1, metal-oxide-semiconductor M1(Metal Oxide Semiconductor Field Effect Transistor, i.e. MOS type field effect transistor) and Voltage Regulator Module 120.
Wherein, the reverse input end of described operational amplifier U1 is connected with the PMIC module 110 of portable terminal, the positive input of operational amplifier U1 is by the output port Vout of Voltage Regulator Module 120 connection LDO circuit, and the output terminal of operational amplifier U1 connects the grid level G of described metal-oxide-semiconductor M1; The drain D of described metal-oxide-semiconductor M1 connects the output port Vout of LDO circuit, and the source S of metal-oxide-semiconductor M1 connects power supply Vbat or battery.
In the present embodiment, described metal-oxide-semiconductor M1 is the P channel MOS tube, and the main on-off action that rises in circuit can make the stable voltage of LDO circuit output.
Please continue to consult Fig. 2, described Voltage Regulator Module 120 comprises first resistance R 1 and second resistance R 2; Described first resistance R 1 is connected between the output port Vout of the positive input of operational amplifier U1 and LDO circuit, an end concatenation operation amplifier U1 positive input of second resistance R 2, other end ground connection.The present invention can make the required magnitude of voltage of functional chip work in the LDO circuit output portable terminal by the resistance that first resistance R 1 and second resistance R 2 are set.
In order to improve the stability of LDO circuit working, also comprise first capacitor C 1 at described LDO circuit, the reverse input end of an end concatenation operation amplifier U1 of described first capacitor C 1, the other end ground connection of first capacitor C 1.In this LDO circuit, described first capacitor C 1 mainly strobes, and makes operational amplifier U1 can obtain level and smooth stable voltage.
In a further embodiment, described LDO circuit also comprises second capacitor C 2, and an end of described second capacitor C 2 connects the drain electrode of metal-oxide-semiconductor M1, second capacitor C, 2 other end ground connection.This second capacitor C 2 mainly plays the bypass effect in circuit, the unnecessary voltage turn-on that makes the output of LDO circuit is to ground.
Below the realization principle of LDO circuit that the embodiment of the invention is provided be described in detail:
In the LDO circuit, operational amplifier U1 is used for constituting feedback circuit with metal-oxide-semiconductor M1, thereby realizes the stable output of voltage.
Vref is the reference voltage of PMIC module 110 in the mobile phone, and this voltage is the reference voltage of whole cell phone system power supply, generally about 1.2V.
Because the reverse input end of operational amplifier U1 directly is connected on the reference voltage output terminal mouth Vref of PMIC module 110, therefore, the reverse input end voltage of operational amplifier U1 is Vref.And because operational amplifier U1 is an ideal operational amplificr, so the positive input voltage V2 of operational amplifier U1 also is Vref.
And in the LDO circuit,
Therefore can obtain:
In formula (2), because Vref is the voltage of determining, so only need to adjust
Value, just can realize the different voltage of output port Vout output of LDO circuit.
For example, as the reference voltage Vref=1.2V of PMIC module 110 outputs, only need make
=1.5, promptly
, just can make the LDO circuit export the voltage of 1.8V.When the LDO circuit need be exported other magnitude of voltage, the resistance that only needs to regulate first resistance R 1 and second resistance R 2 got final product.
In sum, a kind of used for mobile terminal LDO circuit provided by the invention, it comprises operational amplifier, metal-oxide-semiconductor and Voltage Regulator Module, constitute feedback circuit by operational amplifier and metal-oxide-semiconductor, by the resistance of Voltage Regulator Module is set, make the required voltage of LDO circuit output cell-phone function chip operation then.Its electronic component that adopts of the LDO circuit that the embodiment of the invention provides is few, and the price of the electronic component that adopts is very cheap, has reduced the cost of portable terminal, has increased the competitive power of portable terminal on market.
Be understandable that, for those of ordinary skills, can be equal to replacement or change according to technical scheme of the present invention and inventive concept thereof, and all these changes or replacement all should belong to the protection domain of the appended claim of the present invention.
Claims (6)
1. a used for mobile terminal LDO circuit is characterized in that, comprises operational amplifier, metal-oxide-semiconductor and Voltage Regulator Module; The reverse input end of described operational amplifier is connected with the PMIC module of portable terminal, and positive input is by the output port of described Voltage Regulator Module connection LDO circuit, and the output terminal of operational amplifier connects the grid level of described metal-oxide-semiconductor; The drain electrode of described metal-oxide-semiconductor connects the output port of LDO circuit, and the source electrode of metal-oxide-semiconductor connects power supply.
2. used for mobile terminal LDO circuit according to claim 1 is characterized in that described Voltage Regulator Module comprises first resistance and second resistance; Described first resistance string is associated between the output port of the positive input of operational amplifier and LDO circuit, an end concatenation operation amplifier positive input of second resistance, other end ground connection.
3. used for mobile terminal LDO circuit according to claim 1 and 2 is characterized in that, also comprises first electric capacity, the reverse input end of an end concatenation operation amplifier of described first electric capacity, other end ground connection.
4. used for mobile terminal LDO circuit according to claim 1 and 2 is characterized in that, also comprises second electric capacity, and an end of described second electric capacity connects the drain electrode of metal-oxide-semiconductor, other end ground connection.
5. used for mobile terminal LDO circuit according to claim 1 is characterized in that described metal-oxide-semiconductor is the P channel MOS tube.
6. used for mobile terminal LDO circuit according to claim 1 is characterized in that described portable terminal is a mobile phone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105395644A CN101995896A (en) | 2010-11-11 | 2010-11-11 | LDO (Low Drop Output) circuit for mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105395644A CN101995896A (en) | 2010-11-11 | 2010-11-11 | LDO (Low Drop Output) circuit for mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101995896A true CN101995896A (en) | 2011-03-30 |
Family
ID=43786154
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105395644A Pending CN101995896A (en) | 2010-11-11 | 2010-11-11 | LDO (Low Drop Output) circuit for mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101995896A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107045369A (en) * | 2017-02-07 | 2017-08-15 | 努比亚技术有限公司 | A kind of power circuit, terminal and voltage output method |
| CN114089802A (en) * | 2021-11-30 | 2022-02-25 | 荣耀终端有限公司 | Power supply circuit, terminal device and voltage control method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1989683A (en) * | 2004-05-03 | 2007-06-27 | 崇贸科技股份有限公司 | Low dropout voltage regulator providing adaptive compensation |
| CN101075143A (en) * | 2006-05-17 | 2007-11-21 | 深圳安凯微电子技术有限公司 | Low-voltage linear adjuster |
| CN101763131A (en) * | 2008-12-24 | 2010-06-30 | 东部高科股份有限公司 | Low-dropout voltage regulator and operating method of the same |
| CN101853040A (en) * | 2010-07-05 | 2010-10-06 | 复旦大学 | High mains rejection ratio low dropout voltage linear voltage regulator with feedforward transconductance |
-
2010
- 2010-11-11 CN CN2010105395644A patent/CN101995896A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1989683A (en) * | 2004-05-03 | 2007-06-27 | 崇贸科技股份有限公司 | Low dropout voltage regulator providing adaptive compensation |
| CN101075143A (en) * | 2006-05-17 | 2007-11-21 | 深圳安凯微电子技术有限公司 | Low-voltage linear adjuster |
| CN101763131A (en) * | 2008-12-24 | 2010-06-30 | 东部高科股份有限公司 | Low-dropout voltage regulator and operating method of the same |
| CN101853040A (en) * | 2010-07-05 | 2010-10-06 | 复旦大学 | High mains rejection ratio low dropout voltage linear voltage regulator with feedforward transconductance |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107045369A (en) * | 2017-02-07 | 2017-08-15 | 努比亚技术有限公司 | A kind of power circuit, terminal and voltage output method |
| CN114089802A (en) * | 2021-11-30 | 2022-02-25 | 荣耀终端有限公司 | Power supply circuit, terminal device and voltage control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106774580B (en) | A kind of LDO circuit of fast transient response high PSRR | |
| CN103917012B (en) | A kind of white LED driver system with under-voltage locking and overheat protector module | |
| CN105334900B (en) | Fast transient response low pressure difference linear voltage regulator | |
| CN103218003B (en) | Low-dropout voltage stabilizer with multiple power sources input | |
| CN102204072B (en) | Delayed control transfer circuit and power supply system | |
| CN105446404A (en) | Low dropout linear regulator circuit, chip and electric device | |
| CN201867672U (en) | LDO (Low Dropout Regulator) circuit in mobile terminal | |
| CN105242734A (en) | High-power LDO circuit without externally setting capacitor | |
| CN203204489U (en) | Low-dropout regulator with multi-power input | |
| CN104536506B (en) | Linear voltage regulator | |
| CN101931375A (en) | Amplifying circuit with high power supply rejection ratio | |
| CN108241396A (en) | A kind of low pressure difference linear voltage regulator for improving transient response speed | |
| CN104615185B (en) | A kind of reference voltage source start-up circuit | |
| CN203522681U (en) | Double-time-delay power-on sequential control circuit | |
| CN102707755A (en) | Linear voltage regulator with built-in compensation capacitor | |
| CN103792982A (en) | Low dropout linear regulator without external capacitor | |
| CN107272808B (en) | A kind of LDO circuit applied to integrated chip | |
| CN107704005A (en) | Negative voltage linear stable | |
| CN202711106U (en) | Linear voltage regulator with internally-installed compensation capacitor | |
| CN109725673A (en) | A kind of fully integrated multi output stack low pressure difference linear voltage regulator | |
| CN104317345A (en) | Low dropout regulator on basis of active feedback network | |
| CN103713679B (en) | A kind of LDO circuit based on discrete component | |
| CN101995896A (en) | LDO (Low Drop Output) circuit for mobile terminal | |
| US20140375250A1 (en) | Charging apparatus | |
| CN103760942B (en) | Be applicable to the transient state intensifier circuit of low pressure difference linear voltage regulator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20110330 |