CN201867672U - LDO (Low Dropout Regulator) circuit in mobile terminal - Google Patents
LDO (Low Dropout Regulator) circuit in mobile terminal Download PDFInfo
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- CN201867672U CN201867672U CN2010206014433U CN201020601443U CN201867672U CN 201867672 U CN201867672 U CN 201867672U CN 2010206014433 U CN2010206014433 U CN 2010206014433U CN 201020601443 U CN201020601443 U CN 201020601443U CN 201867672 U CN201867672 U CN 201867672U
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- ldo circuit
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- operational amplifier
- ldo
- portable terminal
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Abstract
The utility model discloses an LDO (Low Dropout Regulator) circuit in a mobile terminal, comprising an operational amplifier, an MOS (Metal Oxide Semiconductor) tube and a voltage regulating module. 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 of the LDO circuit by the voltage regulating module; the output end of the operational amplifier is connected with the grid electrode of the MOS tube; the drain electrode of the MOS tube is connected with the output port of the LDO circuit; and the source electrode of the MOS tube is connected with a power supply. In the LDO circuit in the mobile terminal, the operational amplifier and the MOS tube form a feedback circuit; by setting the resistance of the voltage regulating module, the LDO circuit can output the voltage needed by a functional chip of a mobile phone in working; and the LDO circuit adopts few electronic components which are cheap in price, so that the cost of the mobile terminal is lowered, and the competiveness of the mobile terminal on the market is improved.
Description
Technical field
The utility model relates to communication technical field, particularly a kind of LDO circuit that is used for portable terminal.
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 purpose of this utility model is to provide a kind of LDO circuit that is used for portable terminal, and the required voltage of various functional chip work in the portable terminal can be provided.
In order to achieve the above object, the utility model has been taked following technical scheme:
A kind of LDO circuit that is used for portable terminal 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.
The described LDO circuit that is used for portable terminal, 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.
The described LDO circuit that is used for portable terminal 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.
The described LDO circuit that is used for portable terminal 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.
The described LDO circuit that is used for portable terminal, wherein, described metal-oxide-semiconductor is the P channel MOS tube.
The described LDO circuit that is used for portable terminal, wherein, described portable terminal is a mobile phone.
A kind of LDO circuit that is used for portable terminal that the utility model provides, 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.The electronic component that the LDO circuit that the utility model embodiment 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 utility model embodiment.
The circuit theory diagrams of the LDO circuit that Fig. 2 provides for the utility model embodiment.
Embodiment
The utility model provides a kind of LDO circuit that is used for portable terminal, and is clearer, clear and definite for making the purpose of this utility model, technical scheme and effect, below with reference to accompanying drawing and give an actual example the utility model is further described.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
The LDO circuit that the utility model embodiment 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 utility model 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 utility model embodiment 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 LDO circuit that is used for portable terminal that the utility model provides, 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 utility model embodiment 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 the technical solution of the utility model and utility model design thereof, and all these changes or replacement all should belong to the protection domain of the appended claim of the utility model.
Claims (6)
1. a LDO circuit that is used for portable terminal 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. the LDO circuit that is used for portable terminal 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. the LDO circuit that is used for portable terminal 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. the LDO circuit that is used for portable terminal 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. the LDO circuit that is used for portable terminal according to claim 1 is characterized in that described metal-oxide-semiconductor is the P channel MOS tube.
6. the LDO circuit that is used for portable terminal 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 |
|---|---|---|---|
| CN2010206014433U CN201867672U (en) | 2010-11-11 | 2010-11-11 | LDO (Low Dropout Regulator) circuit in mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206014433U CN201867672U (en) | 2010-11-11 | 2010-11-11 | LDO (Low Dropout Regulator) circuit in mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201867672U true CN201867672U (en) | 2011-06-15 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206014433U Expired - Fee Related CN201867672U (en) | 2010-11-11 | 2010-11-11 | LDO (Low Dropout Regulator) circuit in mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201867672U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102595710A (en) * | 2012-01-16 | 2012-07-18 | 惠州Tcl移动通信有限公司 | Drive circuit of keyboard lamp of mobile terminal |
| CN105356422A (en) * | 2015-10-22 | 2016-02-24 | 上海斐讯数据通信技术有限公司 | Method and system for preventing overcurrent and overvoltage damages in test of electronic equipment |
| US9785222B2 (en) | 2014-12-22 | 2017-10-10 | Qualcomm Incorporated | Hybrid parallel regulator and power supply combination for improved efficiency and droop response with direct current driven output stage attached directly to the load |
| US9806707B2 (en) | 2014-02-07 | 2017-10-31 | Qualcomm Incorporated | Power distribution network (PDN) conditioner |
| US9891646B2 (en) | 2015-01-27 | 2018-02-13 | Qualcomm Incorporated | Capacitively-coupled hybrid parallel power supply |
-
2010
- 2010-11-11 CN CN2010206014433U patent/CN201867672U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102595710A (en) * | 2012-01-16 | 2012-07-18 | 惠州Tcl移动通信有限公司 | Drive circuit of keyboard lamp of mobile terminal |
| CN102595710B (en) * | 2012-01-16 | 2015-01-21 | 惠州Tcl移动通信有限公司 | Drive circuit of keyboard lamp of mobile terminal |
| US9806707B2 (en) | 2014-02-07 | 2017-10-31 | Qualcomm Incorporated | Power distribution network (PDN) conditioner |
| US9785222B2 (en) | 2014-12-22 | 2017-10-10 | Qualcomm Incorporated | Hybrid parallel regulator and power supply combination for improved efficiency and droop response with direct current driven output stage attached directly to the load |
| US9891646B2 (en) | 2015-01-27 | 2018-02-13 | Qualcomm Incorporated | Capacitively-coupled hybrid parallel power supply |
| CN105356422A (en) * | 2015-10-22 | 2016-02-24 | 上海斐讯数据通信技术有限公司 | Method and system for preventing overcurrent and overvoltage damages in test of electronic equipment |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110615 Termination date: 20121111 |