CN102647078A - Synchronous switching type voltage-reducing chip - Google Patents
Synchronous switching type voltage-reducing chip Download PDFInfo
- Publication number
- CN102647078A CN102647078A CN2011100434115A CN201110043411A CN102647078A CN 102647078 A CN102647078 A CN 102647078A CN 2011100434115 A CN2011100434115 A CN 2011100434115A CN 201110043411 A CN201110043411 A CN 201110043411A CN 102647078 A CN102647078 A CN 102647078A
- Authority
- CN
- China
- Prior art keywords
- unit
- voltage
- input
- control
- output
- 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 relates to a synchronous switching type voltage-reducing chip comprising an input unit, a control switch, a voltage drop unit, a sampling unit, a judging unit and a control unit. The control unit comprises a first end, a second end and a control end, and the second end is connected with the first end. The input end of the input unit is connected to an external power supply, and the output end of the input unit is connected to the first end. The voltage drop unit has a rated current, and the voltage input end of the voltage drop unit is connected to the second end. The sampling unit is connected to the output end and is used for determining the voltage drop of the input unit. When the current flowing through the input unit is larger than the rated current, the sampling unit outputs a first comparison result. The judging unit is connected to the sampling unit and is used for generating a first judgment signal according to a first comparison result. The control unit is connected to the judging unit and is used for generating a first control signal to the control end so as to disconnect the first end and the second end according to the first judging signal, thus the external power supply and the voltage drop unit are disconnected.
Description
Technical field
The present invention relates to a kind of synchronous suitching type step-down chip.
Background technology
At present, suitching type step-down chip (Synchronous Buck Regulator) is widely used in the power module synchronously.Existing synchronous suitching type step-down chip generally comprises a voltage input end, a pressure drop unit and a voltage output end.Said voltage input end is connected to an external power source; Said pressure drop unit has a rated current; It is used for the voltage of external power source is adjusted downward to a predetermined operating voltage; Said voltage output end export said predetermined operating voltage and offer digital signal processor (digital signalprocessor, DSP), (graphics processing unit GPU) waits chip to GPU.
Yet; Existing suitching type step-down chip does not have the hot plug defencive function; Be said voltage input end when directly inserting external power source, the immediate current that can cause flowing into said pressure drop unit is excessive, when immediate current damages said synchronous suitching type step-down chip during greater than said rated current easily.
Summary of the invention
In view of this, be necessary to provide a kind of synchronous suitching type step-down chip with hot plug defencive function.
A kind of synchronous suitching type step-down chip, it comprises an input unit, a control switch, a pressure drop unit, a sampling unit, a judging unit and a control unit.Said control switch comprises one first end, second end that is connected with said first end and a control end.Said input unit comprises an input and an output, and said input is connected to an external power source, and said output is connected to said first end.Said pressure drop unit comprises a voltage input end and a voltage output end, and said voltage input end is connected to said second end, is used for voltage with said external source and is adjusted downward to a predetermined voltage and said predetermined voltage is exported from said voltage output end.Said pressure drop unit has a rated current.Said sampling unit is connected to said output, is used to measure the flow through pressure drop of said input unit of said external power source, and converts said pressure drop into a comparative voltage and one first reference voltage compares.When the electric current of the said input unit of flowing through during greater than said rated current, said comparative voltage is greater than said first reference voltage, one first comparative result of said sampling unit output.Said judging unit is connected to said sampling unit, is used for producing first according to said first comparative result and judges signal.Said control unit comprises a control input end and a control output end; Said control input end is connected to said judging unit; Said control output end is connected to said control end; Be used for judging that according to said first signal produces one first and controls signal to said control end and control said first end and the disconnection of said second end, make said external power source and said pressure drop unit break off.
With respect to prior art; When the electric current of the said input unit of flowing through during greater than the rated current of said pressure drop unit; Can said external power source and said pressure drop unit be broken off through said sampling unit, judging unit and comparing unit, protect said synchronous mode to switch the step-down chip thus.
Description of drawings
Fig. 1 is the circuit diagram of suitching type step-down chip of the present invention.
The main element symbol description
Synchronous suitching type step-down chip 100
First resistance R 1
The one N type FET M1
Voltage input end Vin
Voltage output end Vout
Divider resistance R2
The first comparator U1
Transformer V1
The 2nd N type FET M2
P type FET M3
The first current source S1
The second current source S2
Capacitor C 1
The second comparator U2
Not circuit N1
Gate driver 601
Voltage stabilizing didoe D1
Embodiment
See also Fig. 1, the synchronous suitching type step-down chip 100 of preferred embodiments of the present invention comprises an input unit 10, control switch 20, pressure drop unit 30, sampling unit 40, a judging unit 50 and a control unit 60.Said input unit connects an external power source VDD; Said control switch 20 is connected to said input unit 10; Said pressure drop unit 30 is connected to said control switch 20; Said sampling unit 40 is connected to said input unit 10, and said judging unit 50 is connected to said sampling unit 40, and said control unit 60 connects said judging unit 50 and said control switch 20.
Said input unit 10 is one first resistance R 1.Said first resistance R 1 comprises an input 101 and an output 102.The input 101 of said first resistance R 1 is connected to said external power source VDD, and in this execution mode, said external power source VDD is 12 volts, and the resistance of said first resistance R 1 is 0.02 ohm.
Said control switch 20 comprises one first end, second end and a control end.Particularly, said control switch 20 is one the one N type FET M1, and said first end, second end and control end are respectively source electrode, drain electrode and the grid of a said N type FET M1.The source electrode of a said N type FET M1 is connected to the output 102 of said first resistance R 1.
Said pressure drop unit 30 has a rated current, comprises a voltage input end Vin and a voltage output end Vout, and said voltage input end Vin is connected to the drain electrode of a said N type FET M1.Said pressure drop unit 30 be used for the voltage from said voltage input end Vin input be adjusted downward to a predetermined voltage and with said predetermined voltage from voltage output end Vout output, then said predetermined voltage is offered other electric elements (not shown).In this execution mode, said predetermined voltage is 3.3 volts.
Said sampling unit 40 comprises a divider resistance R2, first a comparator U1 and a transformer V1.Said divider resistance R2 is connected between the output 102 of positive input terminal and said first resistance R 1 of the said first comparator U1.Said transformer V1 is connected between the negative input end and said external power source VDD of the said first comparator U1.Said transformer V1 is used for said external power source VDD is adjusted to after one first reference voltage Vref 1 negative input end that said first reference voltage Vref 1 is inputed to the said first comparator U1.In this execution mode, said first reference voltage Vref 1 is 47 millivolts, and the resistance of said divider resistance R2 is 1 kilohm.
Said judging unit 50 comprise one the 2nd N type FET M2, P type FET M3, first current source S1, second current source S2, capacitor C 1, second comparator U2, with a not circuit N1.The grid of said the 2nd N type FET M2 is connected to the output of the said first comparator U1, its drain electrode is connected to said P type FET M3 behind the said second current source S2 through the source electrode that is connected to an internal electric source Vcc, said the 2nd N type FET M2 behind the said first current source S1 drain electrode.Said internal electric source Vcc is used for to said first current source S1 power supply.The grid of said P type FET M3 is connected to the output of the said first comparator U1, the source ground of said P type FET M3.Said capacitor C 1 is connected between the source electrode and ground of said the 2nd N type FET M2.The positive input terminal of the said second comparator U2 is connected to the source electrode of said the 2nd N type effect pipe M2, and the negative input end of the said second comparator U2 is connected to said second reference voltage Vref 2.The input of said not circuit N1 is connected to the output of the said second comparator U2.In this execution mode, said internal electric source Vcc is 5 volts, and said first current source is 65 micromicroamperes.Said second current source is 3.5 micromicroamperes, and said second reference voltage Vref 2 is 1.23 volts.
Said control unit 60 comprises a gate driver 601 (gate driver), a charge pump 602 (charge pump) and a voltage stabilizing didoe D1.The input of said gate driver 601 is the control input end of said control unit 60, and the control input end of said gate driver 601 is connected to the output of said not circuit N1.Said charge pump 602 is connected to said internal electric source Vcc and said gate driver 601, and said internal electric source Vcc is used for to said charge pump 602 chargings.The output of said charge pump 602 is the control output end of said control unit 60, and the output of said charge pump 602 is connected to the grid of a said N type FET M1.The backward end of said voltage stabilizing didoe D1 is connected to the output of said charge pump 602, its forward end ground connection.The reverse breakdown voltage of said voltage stabilizing didoe D1 is 16.2 volts.
When initial; Said external power source VDD provides high level to the source electrode of a said N type FET M1 after said first resistance R 1; Said gate driver 601 output one high level are also controlled said charge pump 602 output high level; Therefore, source electrode and the drain electrode of a said N type FET M1 are conducted.The flow through electric current I of said first resistance R 1 of said external power source VDD produces a pressure drop Δ V in said first resistance R 1, and the voltage of the output 102 of said first resistance R 1 promptly equals said pressure drop Δ V.Said pressure drop Δ V converts a comparative voltage to behind said divider resistance R2, said comparative voltage inputs to the positive input terminal of the said first comparator U1.
Understandable, when said electric current I increases, said pressure drop Δ V will increase, and said comparative voltage also will increase, and when said electric current I reaches a critical value, said comparative voltage will equal said first reference voltage Vref 1.In this execution mode, be said rated current with the said critical value setting of electric current I.When said electric current I during greater than said rated current, said comparative voltage is greater than said first reference voltage Vref 1.
When said comparative voltage during greater than said first reference voltage Vref 1, the said first comparator U1 will export first comparative result, and said first comparative result is a high level.Said first comparative result is sent to the grid of said the 2nd N type FET M2 and the grid of said P type FET M3 respectively.Said the 2nd N type FET M2 conducting, said P type FET M3 breaks off.The said first current source S 1 will charge to said capacitor C 1; The positive input terminal of the said second comparator U2 will be detected the voltage of said capacitor C 1; When the voltage of the positive input terminal of the said second comparator U2 during greater than said second reference voltage Vref 2; The said second comparator U2 will export a high level to said not circuit N1, state not circuit N1 and export said low level (first judges signal) to said gate driver 601.Said gate driver 601 is closed said charge pump 602 according to the low level that receives (first judges signal); Make the grid of said charge pump 602 output low levels (first control signal) to a said N type FET; Source electrode and its drain electrode of a said N type FET M1 are broken off; And then said external power source VDD and said pressure drop unit 30 are broken off, protect said synchronous suitching type step-down chip 100 not to be damaged.
When said comparative voltage during less than first reference voltage Vref 1, the said first comparator U1 will export second comparative result, and said second comparative result is a low level.Said second comparative result is sent to the grid of said the 2nd N type FET M2 and the grid of said P type FET M3 respectively.Said the 2nd N type FET M2 will break off, and said P type FET M3 is with conducting.Said capacitor C 1 is discharged through the said second current source S2 ground connection; The positive input terminal of the said second comparator U2 is detected the voltage of said capacitor C 1 less than said second reference voltage Vref 2; The said second comparator U2 will export a low level and export said not circuit N1 to, and the said second comparator U2 is reversed high level (second judges signal) to said gate driver 601 with the low level of output through said not circuit N1.Said gate driver 601 is kept the output high level according to the said charge pump 602 of the high level that receives (second judges signal) control; Make the grid of charge pump 602 output high level (second control signal) to said N type FETs; Keep the source electrode of a said N type FET M1 and the conducting state of its drain electrode; Make said external power source VDD and 30 conductings of said pressure drop unit; Said external power source is imported from said voltage input end Vin, by said pressure drop unit 30 said external power source is adjusted downward to behind the said predetermined voltage by said voltage output end Vout output.In this execution mode, said predetermined voltage is 3.3 volts.In a word; Those skilled in the art will be appreciated that; Above execution mode only is to be used for explaining the present invention; And be not to be used as qualification of the present invention, as long as within connotation scope of the present invention, appropriate change that above embodiment did is all dropped within the scope that the present invention requires to protect with changing.
Claims (9)
1. synchronous suitching type step-down chip, it comprises an input unit, a control switch, a pressure drop unit, a sampling unit, a judging unit and a control unit; Said control switch comprises one first end, second end that is connected with said first end and a control end;
Said input unit comprises an input and an output, and said input is connected to an external power source, and said output is connected to said first end;
Said pressure drop unit comprises a voltage input end and a voltage output end, and said voltage input end is connected to said second end, is used for voltage with said external source and is adjusted downward to a predetermined voltage and said predetermined voltage is exported from said voltage output end; Said pressure drop unit has a rated current;
Said sampling unit is connected to said output, is used to measure the flow through pressure drop of said input unit of said external power source, and converts said pressure drop into a comparative voltage and one first reference voltage compares;
When the electric current of the said input unit of flowing through during greater than said rated current, said comparative voltage is greater than said first reference voltage, one first comparative result of said sampling unit output;
Said judging unit is connected to said sampling unit, is used for producing first according to said first comparative result and judges signal;
Said control unit comprises a control input end and a control output end; Said control input end is connected to said judging unit; Said control output end is connected to said control end; Be used for judging that according to said first signal produces one first and controls signal to said control end and control said first end and break off mutually with said second end, make the disconnection of said external power source and said pressure drop unit.
2. synchronous suitching type step-down chip as claimed in claim 1 is characterized in that, when the electric current that flows through said input unit during less than institute's rated current, said comparative voltage is less than said first reference voltage, and said sampling unit is exported one second comparative result; Said judging unit also is used for producing second according to said second comparative result and judges signal; Said control unit also is used for judging that according to said second signal produces one second and controls signal to said control end and keep said first end and said second end is conducted.
3. synchronous suitching type step-down chip as claimed in claim 1 is characterized in that said input unit is one first resistance.
4. synchronous suitching type step-down chip as claimed in claim 1 is characterized in that said control switch is one the one a N type FET, and said first end, second end and control end are respectively source electrode, drain electrode and the grid of a said N type FET.
5. synchronous suitching type step-down chip as claimed in claim 3 is characterized in that said sampling unit comprises a divider resistance, first comparator and a transformer; Said divider resistance is connected between the output of positive input terminal and said first resistance of said first comparator; Said transformer is connected between the negative input end and said external power source of said first comparator, and said transformer is used for said external power source is adjusted to behind said first reference voltage negative input end that said first reference voltage is inputed to said first comparator.
6. synchronous suitching type step-down chip as claimed in claim 1 is characterized in that said control unit comprises a gate driver, a charge pump and a voltage stabilizing didoe, and the input of said gate driver is connected to the output of said not circuit; The input of said charge pump is connected to said external power source, and said electric charge delivery side of pump is connected to the grid of a said N type FET, and the backward end of said voltage stabilizing didoe is connected to said electric charge delivery side of pump, its forward end ground connection.
7. synchronous suitching type step-down chip as claimed in claim 6 is characterized in that the reverse breakdown voltage of said voltage stabilizing didoe is 16.2 volts.
8. synchronous suitching type step-down chip as claimed in claim 2 is characterized in that said external power source is 12 volts, and said predetermined voltage is 3.3 volts.
9. synchronous suitching type step-down chip as claimed in claim 3 is characterized in that said first resistance is 0.02 ohm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100434115A CN102647078A (en) | 2011-02-22 | 2011-02-22 | Synchronous switching type voltage-reducing chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100434115A CN102647078A (en) | 2011-02-22 | 2011-02-22 | Synchronous switching type voltage-reducing chip |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102647078A true CN102647078A (en) | 2012-08-22 |
Family
ID=46659718
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011100434115A Pending CN102647078A (en) | 2011-02-22 | 2011-02-22 | Synchronous switching type voltage-reducing chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102647078A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101188381A (en) * | 2006-11-22 | 2008-05-28 | 恩益禧电子股份有限公司 | DC-DC converter |
| US20090212851A1 (en) * | 2008-02-27 | 2009-08-27 | Osamu Yamashita | Power supply unit |
| CN101594048A (en) * | 2009-03-19 | 2009-12-02 | 深圳市联德合微电子有限公司 | A kind of PWM type buck converter with overcurrent protection function |
-
2011
- 2011-02-22 CN CN2011100434115A patent/CN102647078A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101188381A (en) * | 2006-11-22 | 2008-05-28 | 恩益禧电子股份有限公司 | DC-DC converter |
| US20090212851A1 (en) * | 2008-02-27 | 2009-08-27 | Osamu Yamashita | Power supply unit |
| CN101594048A (en) * | 2009-03-19 | 2009-12-02 | 深圳市联德合微电子有限公司 | A kind of PWM type buck converter with overcurrent protection function |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9859737B2 (en) | Method and apparatus for performing system power management in electronic device equipped with battery | |
| US9075422B2 (en) | Voltage regulator circuit with adaptive current limit and method for operating the voltage regulator circuit | |
| CN104331141A (en) | Overcurrent protection circuit and server thereof | |
| US20130293213A1 (en) | Start-up circuit and method thereof | |
| CN104466886B (en) | Load protection circuit and load protective method | |
| US20140229748A1 (en) | Apparatus and method for optimizing use of nvdc chargers | |
| CN101656528A (en) | Semiconductor switch control device | |
| US9590510B1 (en) | Cable IR drop compensation | |
| CN103036196B (en) | Over-pressure safety device and method | |
| US10470283B2 (en) | Discharge method and circuit for USB connector | |
| CN102882246B (en) | Use the system and method that master device is charged by detachable apparatus | |
| CN104143818B (en) | Prevent the device that current-limiting circuit is excessively adjusted | |
| CN201622302U (en) | Overvoltage and overcurrent detecting circuit | |
| CN103457302B (en) | Charging circuit and there is the electronic installation of this charging circuit | |
| CN103604974A (en) | Low-power current detection circuit for current mode DC/DC converter | |
| CN102761239A (en) | Constant current and voltage starting circuit of switch power supply controller | |
| CN102148564B (en) | Voltage conversion circuit | |
| TW201705661A (en) | Power supply module and power supply method using the same | |
| CN202632145U (en) | Low-dropout voltage regulator | |
| US9055649B2 (en) | Control circuit and control method of light emitting device circuit | |
| CN107040250A (en) | A kind of voltage mode drive circuit | |
| CN106033241A (en) | Interface power supply circuit | |
| CN205960636U (en) | Surge current control circuit and power supply unit | |
| CN106602532A (en) | Current limiting circuit, driving method thereof, PMIC protection system and display device protection system | |
| CN103163925B (en) | High efficiency low drop-out 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 | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120822 |