CN201178376Y

CN201178376Y - Driving circuit of electric bicycle

Info

Publication number: CN201178376Y
Application number: CNU2008200571690U
Authority: CN
Inventors: 蒋海林; 纪刚
Original assignee: Will Semiconductor Ltd
Current assignee: Will Semiconductor Ltd
Priority date: 2008-04-11
Filing date: 2008-04-11
Publication date: 2009-01-07
Anticipated expiration: 2018-04-11

Abstract

The utility model discloses a drive circuit of an electric bicycle, which comprises a driver module circuit and an NMOS group, wherein, the driver module circuit is electrically connected with the NMOS group; and the driver module circuit comprises a high voltage grid driver, a first capacitor and a second capacitor. The drive circuit of the electric bicycle adopts WNM75N80 type NMOSFET, has smaller power consumption and greatly improves switch power supply efficiency.

Description

The drive circuit of electric bicycle

Technical field

The utility model relates to a kind of drive circuit, particularly a kind of drive circuit of electric bicycle.

Background technology

MOSFET is a kind of semiconductor device that utilizes field effect to control its size of current, this device not only has characteristics such as volume is little, in light weight, power consumption is low, the life-span is long concurrently, and also have that input impedance height, noise are little, advantages such as Heat stability is good, capability of resistance to radiation are strong, stable manufacturing process, therefore expanded its range of application widely.

MOSFET promptly is the Metal-oxide-semicondutor field effect transistor, and basic structure is to make the control grid with metal or polysilicon, and the control gate pole tension is modulated the size of current in the semiconductor channel, insulate with thin oxide layer between grid and raceway groove.Because be to use voltage control,, only gate capacitance is charged in moment so need not inject input current.MOSFET compares with traditional B JT (bipolar transistor), and the former is a voltage-controlled type, and the latter then is a current-control type: voltage-controlled type only needs to apply certain voltage between grid and source electrode, will produce the electric current that flows through source, drain electrode; And must loading certain electric current between base stage and emitter, current mode could produce the electric current that flows through collector electrode.Because Trench (groove) technology is increasingly mature, the raceway groove conducting resistance of MOSFET is more and more littler, has accomplished milliohm level level at present, is very suitable for power source conversion and switch in the low power dissipation design.MOSFET is in single tube is used simultaneously, the same model that various frequencies, power and switch application are arranged with bipolar transistor, but MOSFET is than the easier driving of BJT, all can be used for drive circuit such as CMOS/TTL/ light lotus root/pulse transformer or the like, and the high input impedance that its insulated gate the had incomparable advantage that is bipolar transistor.

Electric bicycle is as a kind of novel, environmental protection, the energy-conservation vehicles, be subjected to everybody liking deeply, annual all keep 10% growth rate, become the basic demand of electric bicycle system development so safety, system conformance are good, good stability, efficient height, cost are low etc.

Power supply service efficiency for the electronic product that improves, need to provide under the situation of great supply current (generally reaching more than the 20-30 ampere) simultaneously, MOS switch control valve in the power-supply management system just can not be integrated within the power management chip, can only select outside extended power (Power) MOSFET or BJT and external drive to realize the DC/DC function.And BJT is the current-mode control device, be not easy to drive, and autophage power is bigger, generally should not adopt.

The utility model content

The technical problems to be solved in the utility model is in order to overcome defective of the prior art, a kind of drive circuit of electric bicycle is provided, the drive circuit of this electric bicycle adopts WNM75N80 type NMOSFET, and oneself power consumption is smaller, greatly improves switch power efficiency.

The utility model solves above-mentioned technical problem by following technical proposals: a kind of drive circuit of electric bicycle, its substantive distinguishing features is, it comprises a driver module circuit and NMOS group, this driver module circuit and this NMOS group electrically connect, this driver module circuit comprises a high pressure gate drivers, one first electric capacity and one second electric capacity, this first electric capacity, this second electric capacity all and this high pressure gate drivers electrically connect.

Wherein, this NMOS group comprises NMOSFET pipe and the 2nd NMOSFET pipe.

Wherein, the source electrode of a NMOSFET pipe is connected with the drain electrode of the 2nd NMOSFET pipe.

Wherein, the drain electrode of a NMOSFET pipe directly is connected with high voltage source.

Wherein, NMOSFET pipe and the power MOSFET tube of the 2nd NMOSFET pipe for making by trench process.

Wherein, this high pressure gate drivers comprises a power end, a high signal pins and a low signal pin, and this power end receives outside power supply, and this high signal pins and this low signal pin receive outside high and low pulse-width signal respectively.

Wherein, this high pressure gate drivers comprises that also a upper end drives output pin, a upper end drive controlling pin and a lower end and drives output pin, this upper end drives output pin and is connected with the grid of a NMOSFET pipe, this upper end drive controlling pin is connected with source electrode with a NMOSFET pipe, and this lower end drives output pin and is connected with the grid of the 2nd NMOSFET pipe.

Wherein, this first electric capacity is filter capacitor, and it is between power end and ground connection.

Wherein, this high pressure gate drivers also comprises a upper end driving power pin, and this second electric capacity is bootstrap capacitor, and this second electric capacity is between upper end driving power pin and upper end drive controlling pin.

Wherein, the drive circuit of this electric bicycle is a synchronous rectification reduction voltage circuit.

Positive progressive effect of the present utility model is:

1, circuit structure is simple, and required peripheral components is few, be applicable in most of Switching Power Supply large-current electric origin system, and oneself power consumption is smaller, greatly improves switch power efficiency;

2, owing to adopt the integrated circuit (IC) chip control model, the consistency of system parameters, stability are better;

3, adopt the WNM75N80 type NMOSFET of Trench technology manufacturing simultaneously, greatly reduced system's production cost, obtained certain market approval at present, have very high practical value with domestic corporation's independent development.

Description of drawings

Fig. 1 is the theory diagram of the utility model one embodiment.

Fig. 2 is the circuit theory diagrams of Fig. 1.

Embodiment

Lift a preferred embodiment below, and come the clearer the utility model that intactly illustrates in conjunction with the accompanying drawings.

Fig. 1 is the theory diagram of the utility model one embodiment.As shown in Figure 1, the drive circuit of the utility model electric bicycle is synchronous rectification step-down (BUCK) circuit, it comprises a driver module circuit and NMOS group, this driver module circuit and this NMOS group electrically connect, and power supply and signal input provide power supply and pulse-width modulation (PWM) signal to this driver module circuit respectively.

Fig. 2 is the circuit theory diagrams of Fig. 1.As shown in Figure 2, this driver module circuit comprises a high pressure gate drivers, first capacitor C 1 and second capacitor C 2, this high pressure gate drivers adopts the LM5107 type, its high signal pins HI and low signal pin LI accept the high and low pwm signal from the outside respectively, its power end VDD connects power supply and is powered by this power supply, this first capacitor C 1 is the filter capacitor of 1uF, and this first capacitor C 1 is between power end VDD and ground connection.This NMOS group comprises that two NMOSFET manage one the one NMOSFET pipe N1 and the 2nd NMOSFET pipe N2, the source electrode of the one NMOSFET pipe N1 is connected with the drain electrode of the 2nd NMOSFET pipe N2, the drain electrode of the one NMOSFET pipe N1 directly is connected with high voltage source HV, and the voltage of this high voltage source HV is about 0-60V.Power (Power) the MOSFET---WNM75N80 type MOSFET pipe that these two NMOSFET pipes all adopt Trench technology to make, the resistance R between its drain electrode and the source electrode _{DS (ON)}Have only several milliohms, so autophage power is very little, to improving the service efficiency of power-supply system, can play remarkable effect, and the low voltage characteristic that opens that WNM75N80 type MOSFET pipe has makes drive circuit become simply, have simultaneously range of safety operation big etc. advantage.The puncture voltage of WNM75N80 type MOSFET pipe internal indicator: Vds is greater than 80V, and the Id electric current is 80A, and conducting resistance is about 9m Ω (Vgs=10V), V _{GS (TH)}=2.7V (Vds=Vgs is during Igs=250uA) adopts the fabulous TO220 packing forms of heat dispersion.Wherein, the upper end of high pressure gate drivers drives output pin HO and is connected with the grid of NMOSFET pipe N1, its lower end drives output pin LO and is connected with the grid of the 2nd NMOSFET pipe N2, and its upper end drive controlling pin HS is connected its grounding leg Vss ground connection with the source electrode of NMOSFET pipe N1.Second capacitor C 2 is a bootstrap capacitor, and it is between the upper end of high pressure gate drivers driving power HB pin and upper end drive controlling HS pin, and this boostrap circuit is mainly given the power supply of the drive circuit in the high pressure gate drivers.

The concrete principle of the drive circuit of the utility model electric bicycle is: at first provide power supply and pwm signal to the driver module circuit by external system, signal is delivered to the grid of NMOSFET pipe N1 and the 2nd NMOSFET pipe N2 through the driver module circuit, control the opening state of these two NMOSFET pipes, produce the work of output signal control subsequent conditioning circuit by output out end.And the high signal HI pin of high pressure gate drivers and low signal LI pin are accepted the pwm signal from peripheral control unit.Whole like this drive part circuit and switch will have been worked, add an inductance and some electric capacity simultaneously, connect a power supply control chip again, just formed a powerful synchronous rectification voltage dropping power supply, its NMOSFET pipe N1 is a transfer tube, play on-off action, be used for to back level induction charging, the main effect of the 2nd NMOSFET pipe N2 is the afterflow effect of playing under NMOSFET pipe N1 turn-offs.

In sum, the utlity model has following technique effect:

Though more than described embodiment of the present utility model, but those skilled in the art is to be understood that, these only illustrate, and under the prerequisite that does not deviate from principle of the present utility model and essence, can make numerous variations or modification to these execution modes.Therefore, protection range of the present utility model is limited by appended claims.

Claims

1, a kind of drive circuit of electric bicycle, it is characterized in that, it comprises a driver module circuit and NMOS group, this driver module circuit and this NMOS group electrically connect, this driver module circuit comprises a high pressure gate drivers, one first electric capacity and one second electric capacity, this first electric capacity, this second electric capacity all and this high pressure gate drivers electrically connect.

2, the drive circuit of electric bicycle as claimed in claim 1 is characterized in that, this NMOS group comprises NMOSFET pipe and the 2nd NMOSFET pipe.

3, the drive circuit of electric bicycle as claimed in claim 2 is characterized in that, the source electrode of a NMOSFET pipe is connected with the drain electrode of the 2nd NMOSFET pipe.

4, the drive circuit of electric bicycle as claimed in claim 3 is characterized in that, the drain electrode of a NMOSFET pipe directly is connected with high voltage source.

5, the drive circuit of electric bicycle as claimed in claim 4 is characterized in that, NMOSFET pipe and the power MOSFET tube of the 2nd NMOSFET pipe for being made by trench process.

6, the drive circuit of electric bicycle as claimed in claim 1, it is characterized in that, this high pressure gate drivers comprises a power end, a high signal pins and a low signal pin, this power end receives outside power supply, and this high signal pins and this low signal pin receive outside high and low pulse-width signal respectively.

7, the drive circuit of electric bicycle as claimed in claim 6, it is characterized in that, this high pressure gate drivers comprises that also a upper end drives output pin, a upper end drive controlling pin and a lower end and drives output pin, this upper end drives output pin and is connected with the grid of a NMOSFET pipe, this upper end drive controlling pin is connected with source electrode with a NMOSFET pipe, and this lower end drives output pin and is connected with the grid of the 2nd NMOSFET pipe.

8, the drive circuit of electric bicycle as claimed in claim 7 is characterized in that, this first electric capacity is filter capacitor, and it is between power end and ground connection.

9, the drive circuit of electric bicycle as claimed in claim 8, it is characterized in that, this high pressure gate drivers also comprises a upper end driving power pin, and this second electric capacity is bootstrap capacitor, and this second electric capacity is between upper end driving power pin and upper end drive controlling pin.

10, the drive circuit of electric bicycle as claimed in claim 8 is characterized in that, the drive circuit of this electric bicycle is a synchronous rectification reduction voltage circuit.