CN104393862A - Miller capacitance characteristic based car power supply starting circuit - Google Patents
Miller capacitance characteristic based car power supply starting circuit Download PDFInfo
- Publication number
- CN104393862A CN104393862A CN201410742876.3A CN201410742876A CN104393862A CN 104393862 A CN104393862 A CN 104393862A CN 201410742876 A CN201410742876 A CN 201410742876A CN 104393862 A CN104393862 A CN 104393862A
- Authority
- CN
- China
- Prior art keywords
- resistance
- channel mos
- mos fet
- variable capacitance
- circuit
- 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
Landscapes
- Networks Using Active Elements (AREA)
Abstract
The invention relates to the field of car circuits and particularly relates to a Miller capacitance characteristic based car power supply starting circuit. The circuit comprises a power supply input end Vi, a power supply output end Vo, a resistor R3, an N-channel MOSFET tube and a variable capacitor Ci. A drain electrode of the N-channel MOSFET tube and one end of the variable capacitor Ci are connected with the power supply input end Vi, the grid electrode of the N-channel MOSFET tube and the other end of the variable capacitor Ci are connected with the power supply input end Vi, one end of the resistor R3 is connected with the grid electrode of the N-channel MOSFET tube, the other end of the resistor R3 is grounded, and a source electrode of the N-channel MOSFET tube is connected with the power supply output end Vo. The circuit is effective for systems with a plurality of power supplies and in demand of sequential control and is simple and low in cost.
Description
Technical field
The present invention relates to vehicle electronic circuit field, particularly relating to a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic.
Background technology
On-vehicle information amusing products function becomes complicated gradually, and system also becomes huge, and functional module also increases gradually, and each functional module all needs Power supply, causes power interface many, and level value also occurs a variety of.Simultaneously complicated function also causes system to have further requirement to power initiation sequential, in order to system stability works reliably, traditional technology generally carries out sequencing control with single-chip microcomputer to each system module, and cost is higher, system also becomes complicated, and workload is larger.
Summary of the invention
The invention provides a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic, utilizing the feature of miller capacitance characteristic, solve the problem that module starts sequential.
The present invention is achieved in that a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic, described circuit comprises power input Vi, power output end Vo, resistance R3, N-channel MOS FET manages and variable capacitance Ci, the drain electrode of described N-channel MOS FET pipe is connected power input Vi with one end of described variable capacitance Ci, the grid of described N-channel MOS FET pipe is connected power input Vi with the other end of described variable capacitance Ci, described resistance R3 one end connects the grid of described N-channel MOS FET pipe, the other end ground connection of described resistance R3, the source electrode of described N-channel MOS FET pipe meets described power output end Vo.
Further technical scheme of the present invention is: described power starting circuit also comprises resistance R1, the contact that the grid of described N-channel MOS FET pipe connects described power input Vi is A, the contact that the other end of described variable capacitance Ci connects described power input Vi is B, and described resistance R1 connects described contact A and described contact B.
Further technical scheme of the present invention is: the contact that one end of described variable capacitance Ci, described resistance R3 are connected with the grid of described N-channel MOS FET pipe is C, and described power starting circuit also comprises the resistance R2 connecting described contact A and described contact C.
Further technical scheme of the present invention is: the inside of described MOSFET pipe also comprises parasitic capacitance Cgd, and described variable capacitance Ci is far longer than parasitic capacitance Cgd.
Further technical scheme of the present invention is: it is microampere order that described resistance R2 and described resistance R3 need meet electric current Vi/ (resistance R2+ resistance R3).
Further technical scheme of the present invention is: resistance R3 > > resistance R2 > > resistance R1.
The invention has the beneficial effects as follows: the present invention is a kind of based on utilizing the vehicle power of miller capacitance characteristic to start timing method, can by configuring different variable capacitance Ci by this circuit, the complete ON time of MOSFET is made to change along with variable capacitance Ci and change, like this, the startup sequential of many power supplys just becomes very simple, and cost is also very low.
Accompanying drawing explanation
Fig. 1 is the circuit diagram that the embodiment of the present invention provides.
Fig. 2 is the MOSFET internal parasitic capacitances equivalent circuit diagram that the embodiment of the present invention provides.
Fig. 3 is that the parasitic capacitance that provides of the embodiment of the present invention is to the influence curve figure of MOSFET turn-on characteristics.
Fig. 4 is that variable capacitance electric capacity Ci changes the V-T curve chart caused.
Embodiment
Parasitic capacitance Cgd: parasitic capacitance generally refers to inductance, resistance, the capacitance characteristic that chip pin etc. show at high frequencies.In fact, an equivalent resistance is in an electric capacity, and an inductance, and the series connection of a resistance, showing in low frequency situation is not clearly, and at high frequencies, equivalence value can increase, and can not ignore.We will take into account in the calculation.ESL is exactly equivalent inductance, and ESR is exactly equivalent resistance.No matter be resistance, electric capacity, inductance, or diode, triode, metal-oxide-semiconductor, also have IC, we will consider their equivalent capacitance value at high frequencies, inductance value.--Baidu is known.Described parasitic capacitance Cgd is exactly the inside equivalent capacity of described MOSFET in this article.
Cgs, Cgd and Cds as shown in Figure 2, are the internal parasitic capacitances of described MOSFET.
As Fig. 1 to 3, a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic, described circuit comprises power input Vi, power output end Vo, resistance R3, N-channel MOS FET manages and variable capacitance Ci, the drain electrode of described N-channel MOS FET pipe is connected power input Vi with one end of described variable capacitance Ci, the grid of described N-channel MOS FET pipe is connected power input Vi with the other end of described variable capacitance Ci, described resistance R3 one end connects the grid of described N-channel MOS FET pipe, the other end ground connection of described resistance R3, the source electrode of described N-channel MOS FET pipe meets described power output end Vo.Utilize the equivalent capacity of miller capacitance inside on the impact of the turn-on characteristics of MOSFET, by regulating the time of external capacitive variable capacitance Ci and adjustable switch.
Described power starting circuit also comprises resistance R1, the contact that the grid of described N-channel MOS FET pipe connects described power input Vi is A, the contact that the other end of described variable capacitance Ci connects described power input Vi is B, and described resistance R1 connects described contact A and described contact B.Reduce the terminal voltage of described variable capacitance electric capacity Ci and described MOSFET, avoid overtension to damage element.
The contact that one end of described variable capacitance Ci, described resistance R3 are connected with the grid of described N-channel MOS FET pipe is C, and described power starting circuit also comprises the resistance R2 connecting described contact A and described contact C.Reduce the terminal voltage of described variable capacitance electric capacity Ci and described MOSFET, avoid overtension to damage element.
The inside of described MOSFET pipe also comprises parasitic capacitance Cgd, and described variable capacitance Ci is far longer than parasitic capacitance Cgd.
It is microampere order that described resistance R2 and described resistance R3 need meet electric current Vi/ (resistance R2+ resistance R3).
Resistance R3 > > resistance R2 > > resistance R1.Resistance R3 > > resistance R2 > > resistance R1: namely described resistance R3 is far longer than described resistance R2, and described resistance R2 is far longer than described resistance R1.
The invention has the beneficial effects as follows: the present invention is a kind of based on utilizing the vehicle power of miller capacitance characteristic to start timing method, can by configuring different variable capacitance Ci by this circuit, the complete ON time of MOSFET is made to change along with variable capacitance Ci and change, like this, the startup sequential of many power supplys just becomes very simple, and cost is also very low.
Embodiments of the invention can also be introduced and be: the object of the invention is to utilize the inner miller capacitance of N-channel MOS FET on the impact of Vgs, shunt capacitance variable capacitance Ci between grid leak pole, N-channel MOS FET can be set by the transition time of amplification region to saturation region, N-channel MOS FET is serially connected on power supply backbone, utilize the change of variable capacitance electric capacity Ci on the impact of Vgs, thus the ON time of power supply can be controlled, make have the circuit starting requirement to become simple to power supply sequential, cost is also very low;
Power input Vi connecting resistance R1, the other one end of resistance R1 is connected to drain electrode and variable capacitance electric capacity Ci one end of N-channel MOS FET, the other termination N-channel MOS FET grid of variable capacitance electric capacity Ci.Power input Vi connecting resistance R2 simultaneously, the other termination of resistance R2 other termination N-channel MOS FET grid and a resistance R3, resistance R3 publicly.N-channel MOS FET source electrode connects power supply and exports Vo.
Choosing each Primary Component, resistance need meet resistance R3 > > resistance R2 > > resistance R1.
Choosing each Primary Component, electric capacity need meet variable capacitance Ci > > parasitic capacitance Cgd.
Resistance R3, resistance R2 are chosen, need meet: Vi/ (resistance R2+ resistance R3) is microampere order, simultaneously Vi* resistance R3/ (resistance R2+ resistance R3) > Vgs(th).
After adding variable capacitance electric capacity Ci between the grid leak pole of N-channel MOS FET, input capacitance is variable capacitance Ciss=Ci+Cgs+Cgd, and the unlatching of N-channel MOS FET can be divided into following 4 processes.In first process, input capacitance variable capacitance Ciss is charged, from 0V to Vth.In this process, most gate leve electric current charges to Cgs.Sub-fraction current direction parasitic capacitance Cgd and variable capacitance electric capacity Ci.When after voltage rise to threshold voltage, the voltage on parasitic capacitance Cgd and variable capacitance electric capacity Ci can reduction a little.This stage is called to open and postpones.Because the drain current of device and drain voltage all remain unchanged.Once grid step voltage is charged to threshold level Vgs(th) on, N-channel MOS FET just to start between DS conduction current.In second process, gate leve voltage rises to Miller platform from Vth.This stage is the linear operating region of device, and electric current is proportional to grid step voltage.In grid level region, electric current, just as first stage, flows to variable capacitance Ciss, and now the voltage of Vgs constantly increases.At the output of device, drain current increases along with the increase of gate leve voltage.But the DS voltage in this time remains on former level.
When entering the three phases of opening process, gate leve has been charged to and enough voltage platforms maintain whole load current has passed through, and rectifier diode is turned off.Also be from this moment.Drain voltage starts to decline and grid step voltage remains unchanged.This region of Vgs is exactly Miller platform, and rectifier diode is turned off.All grid level electric currents of driving chip perform the electric discharge to parasitic capacitance Cgd electric capacity by the change in voltage utilizing DS to hold.The electric current of DS end remains unchanged, because this time, this electric current was controlled by foreign current.
The final step of opening process is the conduction pathway in order to strengthen N-channel MOS FET by adding a higher voltage at grid.The final voltage magnitude of Vgs determines the on state resistance value under device ON state state, and this is by charging with to variable capacitance electric capacity Ciss.Therefore, grid level electric current is now by three capacitive division.When these three electric capacity are charged time, drain current is still constant.
Because parasitic capacitance Cgd and Cgs is the inner intrinsic parameter of N-channel MOS FET, we can not change, so change variable capacitance Ci, namely can change operating state and the service time of N-channel MOS FET.
As Fig. 4.Use this circuit, only need to utilize an electric capacity, namely can change the ON time of N-channel MOS FET.In the system of multiple feed, there are strict requirements is whether power by being connected in series N-channel MOS FET to control on backbone, N-channel MOS FET ON time can be set by variable capacitance Ci for each power initiation sequential, therefore circuit is very simple, and cost is also lower.
Traditional way general Shi You mono-road power supply is first powered to sequencing control MCU, is controlled sequential by this MCU, like this, needs in systems in which to add MCU and power conversion chip, needs to carry out programmed process to MCU simultaneously, and workload is large, and cost is also higher.
The research of the present invention by affecting for N-channel MOS FET conducting MOSFET inside miller capacitance, invent a kind of circuit of cheap and simple, N-channel MOS FET ON time is set by the size of the method miller capacitance adding electric capacity between N-channel MOS FET grid leak pole, need the system of sequencing control very effective for many power supplys, and this invention circuit is simple, cost is lower.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. one kind based on the vehicle power start-up circuit utilizing miller capacitance characteristic, it is characterized in that: described circuit comprises power input Vi, power output end Vo, resistance R3, N-channel MOS FET manages and variable capacitance Ci, the drain electrode of described N-channel MOS FET pipe is connected power input Vi with one end of described variable capacitance Ci, the grid of described N-channel MOS FET pipe is connected power input Vi with the other end of described variable capacitance Ci, described resistance R3 one end connects the grid of described N-channel MOS FET pipe, the other end ground connection of described resistance R3, the source electrode of described N-channel MOS FET pipe meets described power output end Vo.
2. a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic according to claim 1, it is characterized in that: described power starting circuit also comprises resistance R1, the contact that the grid of described N-channel MOS FET pipe connects described power input Vi is A, the contact that the other end of described variable capacitance Ci connects described power input Vi is B, and described resistance R1 connects described contact A and described contact B.
3. a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic according to claim 1 and 2, it is characterized in that: the contact that one end of described variable capacitance Ci, described resistance R3 are connected with the grid of described N-channel MOS FET pipe is C, described power starting circuit also comprises the resistance R2 connecting described contact A and described contact C.
4. a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic according to claim 3, it is characterized in that: the inside of described MOSFET pipe also comprises parasitic capacitance Cgd, described variable capacitance Ci is far longer than parasitic capacitance Cgd.
5. a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic according to claim 4, is characterized in that: it is microampere order that described resistance R2 and described resistance R3 need meet electric current Vi/ (resistance R2+ resistance R3).
6. a kind of vehicle power start-up circuit based on utilizing miller capacitance characteristic according to claim 5, is characterized in that: resistance R3 > > resistance R2 > > resistance R1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410742876.3A CN104393862A (en) | 2014-12-08 | 2014-12-08 | Miller capacitance characteristic based car power supply starting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410742876.3A CN104393862A (en) | 2014-12-08 | 2014-12-08 | Miller capacitance characteristic based car power supply starting circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104393862A true CN104393862A (en) | 2015-03-04 |
Family
ID=52611711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410742876.3A Pending CN104393862A (en) | 2014-12-08 | 2014-12-08 | Miller capacitance characteristic based car power supply starting circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104393862A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108712159A (en) * | 2018-05-03 | 2018-10-26 | 福建科立讯通信有限公司 | A kind of the igniting start-up circuit and method of Vehicle mounted station |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674438A (en) * | 2004-03-23 | 2005-09-28 | 华为技术有限公司 | Circuit for positive power source inputting load electrifying slow starting |
| CN201029021Y (en) * | 2006-08-18 | 2008-02-27 | 杭州华三通信技术有限公司 | Electrical start delaying circuit of positive power |
| US7492212B1 (en) * | 2007-08-21 | 2009-02-17 | Infineon Technologies Ag | Adaptive capacitance for transistor |
| CN201499153U (en) * | 2009-08-27 | 2010-06-02 | 青岛海信宽带多媒体技术有限公司 | Slow start circuit and optical module comprising same |
-
2014
- 2014-12-08 CN CN201410742876.3A patent/CN104393862A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674438A (en) * | 2004-03-23 | 2005-09-28 | 华为技术有限公司 | Circuit for positive power source inputting load electrifying slow starting |
| CN201029021Y (en) * | 2006-08-18 | 2008-02-27 | 杭州华三通信技术有限公司 | Electrical start delaying circuit of positive power |
| US7492212B1 (en) * | 2007-08-21 | 2009-02-17 | Infineon Technologies Ag | Adaptive capacitance for transistor |
| CN201499153U (en) * | 2009-08-27 | 2010-06-02 | 青岛海信宽带多媒体技术有限公司 | Slow start circuit and optical module comprising same |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108712159A (en) * | 2018-05-03 | 2018-10-26 | 福建科立讯通信有限公司 | A kind of the igniting start-up circuit and method of Vehicle mounted station |
| CN108712159B (en) * | 2018-05-03 | 2023-11-28 | 福建科立讯通信有限公司 | Ignition starting circuit and method for vehicle-mounted platform |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104218803B (en) | Bootstrap voltage charging circuit and voltage conversion circuit | |
| CN104170254A (en) | System and apparatus for driver circuit for protection of gates of GaN FETs | |
| CN103647440B (en) | A kind of soft starting circuit and comprise the DC-DC circuit of this soft starting circuit | |
| CN1859001B (en) | DC power slow start circuit | |
| CN104467372B (en) | Switch power controller and control method thereof | |
| CN103441660A (en) | Direct current power supply slow starting circuit of gateway device | |
| CN103795385A (en) | Power tube drive method and circuit, and direct-current solid power controller | |
| CN103532353A (en) | Bootstrap power-supply MOSFET/IGBT (metal-oxide-semiconductor field effect transistor/insulated gate bipolar translator) driving circuit with high negative voltage | |
| CN205484701U (en) | Last electricity time of ICPMU and relapse powering up and down stability test circuit | |
| CN201569970U (en) | Power soft-start device suitable for USB interface equipment | |
| CN106301332B (en) | Circuit for discharging slow-start power supply loop | |
| CN103701308A (en) | Synchronizing power tube driving and bootstrap capacitor charging circuit | |
| CN203434954U (en) | Switching circuit with adjustable rise time and digital product | |
| CN103064376A (en) | Concentrated power supply rack-mounted equipment function module hot plug control system | |
| TW201417276A (en) | Composite semiconductor device | |
| CN203339958U (en) | Peak current detection-based line voltage compensation circuit | |
| CN205249037U (en) | Switch triode from supply circuit , LED drive module and integrated circuit | |
| CN102035409B (en) | Switching power supply control chip | |
| CN107204761B (en) | Power tube driving circuit | |
| US8520353B2 (en) | Electronic device with surge suppression circuit | |
| CN203747779U (en) | Power tube drive circuit and direct-current solid state power controller | |
| US9602096B2 (en) | Power electronic device with improved efficiency and electromagnetic radiation characteristics | |
| CN203933358U (en) | A kind of field effect transistor drive circuit for high frequency low voltage system | |
| CN104979804A (en) | Output over-voltage protection circuit | |
| CN105490515B (en) | Start-up circuit with nF level capacitive loads |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150304 |