CN206559232U - A kind of boost conversion circuit - Google Patents

Abstract

Propose it is a kind of realizes promotion buckling than DC boosting translation circuit by Two Stages, the switching branches of first order booster circuit are made up of two MOS transistors cascades, produce cut-off signals by comparing output voltage with default bias voltage to control its break-make；First order booster circuit works during circuit start, and first order circuit is acted on by cut-off signals after output voltage rise disconnects, while the second booster circuit starts to provide stable high output voltage.

Description

A kind of boost conversion circuit

Technical field

The present invention relates to DC-DC voltage translation circuit.

Background technology

General booster circuit is as shown in figure 1, the switch periodic on or off of T, it is assumed that switch periods are T_S, wherein opening Close ON time t_onFor DT_S, switch OFF time t_offFor (1-D) T_S, here 0<D<1.Then switched voltage output is,

Required output voltage can be obtained by adjusting dutycycle D.

When switching signal or input voltage than it is relatively low when, it is necessary to using the metal-oxide-semiconductor of Low threshold as switching device, but low threshold The MOS of value is smaller with substrate doping due to gate oxide thickness so that its withstanding voltage is low, therefore can not obtain high Output voltage and boosting no-load voltage ratio.In order to obtain high output voltage, it is necessary to using the high switch metal-oxide-semiconductor of withstanding voltage, but so Device gate oxide thickness and substrate doping all than larger, threshold voltage can increase so that electric during low input The difficulty in starting on road.

The present invention proposes a kind of new two-stage DC boosting translation circuit, and height can be obtained under the conditions of low input Output voltage and voltage change ratio.

The content of the invention

Booster circuit is a kind of conventional DC voltage conversion circuit, but when Gao Shixu is compared in output voltage or boosting change Want switching tube that there is larger withstanding voltage, the device architecture needed for big withstanding voltage can cause high threshold value with doping concentration Voltage so that the difficulty in starting of circuit, in order to solve this problem, the present invention proposes a kind of new two-stage DC boosting conversion electricity Road.

The present invention proposes a kind of promotion buckling than DC boosting translation circuit, including first order booster circuit 110, the second level Booster circuit 130, level shift circuit 120, breaking circuit 140.Inductance L in 110 circuits₁With input voltage V_inThe side of connection Simultaneously with transistor M in 140 circuits₂With transistor M₃Drain electrode and 130 circuits in inductance L₂With input voltage V_inThe one of connection Side is connected；Transistor M in 110 circuits₈Grid and 140 circuits in transistor M₂Source electrode connection；Transistor in 110 circuits M₉Grid and 120 circuits in transistor M₁Grid and switching control pulse connection；Diode D in 110 circuits₁, electric capacity C₁ And load resistance R_LCommon port and 130 circuits in inductance L₃Not with diode D₂It is brilliant in the side of connection and 140 circuits Body pipe M₄Grid connection；Transistor M in 120 circuits₁Drain electrode and 130 circuits in transistor M₁₀Grid connection.

Further, the inductance L of the first order booster circuit 110₁Side is connected with input voltage, opposite side and switch branch Road and diode D₁Positive pole connection；Switching branches are by two transistor M₈With M₉Cascade, wherein transistor M₉Grid connection open Close control wave, transistor M₉Drain electrode and transistor M₈Source electrode connection, transistor M₈Grid and breaking circuit 140 The cut-off signals V of output_sw1Connection, transistor M₈Drain electrode and inductance L₁With diode D₁Common port connection；Diode D₁'s Negative pole and output capacitance C₁With resistance R_LA common port connection, output capacitance C₁With load resistance R_LParallel connection, another is public End is grounded altogether.

Further, the breaking circuit 140 is included by transistor M₄With M₅The differential pair of composition, M₄With M₅Source electrode with it is brilliant Body pipe M₆Drain electrode connection, M₆For tail current source；Transistor M₂With M₃Grid and drain electrode short circuit, M₂With M₃Drain electrode connect input electricity Press V_in, M₄Grid meet load resistance RL, M₇Source ground, M₇Drain electrode and load resistance R₂Connection, M₂Source electrode and M₇'s Load resistance R₂The voltage of the common port connected is the cut-off signals V of output_SW1, M₅、M₆、M₇Grid voltage connect biasing respectively Voltage V_B1、V_B3、V_B2。

Further, the second level booster circuit 130 includes inductance L₂, transistor M₁₀, diode D₂, electric capacity C₂, inductance L₃；Inductance L₂Side is connected with input voltage, other side and transistor M₁₀Drain electrode connection, transistor M₁₀Grid and 120 M in circuit₁Drain electrode connection, M₁₀Source ground；Diode D₂Positive pole and M₁₀Drain electrode connection, diode D₂Negative pole with electricity Hold C₂Connection, inductance L₃Side and electric capacity C₂Connection, other side connection load resistance R_L。

Further, the level shift circuit 120 includes transistor M₁With resistance R₁, wherein M₁Grid connecting valve arteries and veins Rush signal, resistance R₁Side and M₁Drain electrode connection, resistance R₁Other side and load resistance R_LConnection.

Brief description of the drawings

Fig. 1 is booster circuit schematic diagram

Fig. 2 is two-stage boost conversion circuit figure

Embodiment

Fig. 2 for the present invention propose promotion buckling than booster circuit figure.Wherein

(1) 110 circuit is first order boost conversion circuit, including M₈,M₉,L₁,D₁,C₁,R_L, wherein M₈,M₉For Low threshold MOS device.

(2) 120 circuits are level shift circuit, including M₁,R₁, M₁For Low threshold MOS device.

(3) 140 circuits are breaking circuit, including M₂、M₃、M₄、M₅、M₆、M₇, R₂。

(4) 130 be second level boost conversion circuit, including L₂,D₂,L₃,C₂,M₁₀,R_L, M₁₀For high threshold voltage devices.

M in 140 circuits₄、M₅For differential pair circuit, M₆For the tail current source of differential pair, M₂With M₃For the metal-oxide-semiconductor of grid leak short circuit It is used as active load, M₇With R₂For output circuit.M₂With M₃Drain electrode meet input voltage V_in, M₄Grid connect boost conversion circuit Output voltage V_out, M₅、M₆、M₇Grid voltage meet bias voltage V respectively_B1、V_B3、V_B2, M₂Source electrode for output shut-off letter Number V_SW1.When circuit start, M₄Grid meets the output V of first order booster circuit_out, now tail current source M₆The electric current provided By M₄And M₅Distribution, the ratio of distribution is by V_outAnd V_B1Size determine, work as M₄Side electric current is smaller, M₂Drain-source pressure drop also compare Cut-off signals V that is small, being exported_SW1First order switch cascade tube M can be ensured₈Conducting；As output voltage V_outRise, M₄Side Electric current increase, M₂Drain-source pressure drop increase therewith, cut-off signals V_SW1Reduce, until first order switch cascade tube is turned off.So The shut-off of first order booster circuit when realizing output voltage increase.

As initial output voltage V_outWhen not high, M₁Drain voltage is than relatively low, M₁₀It can not open, the 2nd grade of booster circuit can not Work；V_outIt is low so that M₄Drain current is smaller, such M₂Source and drain pressure drop is smaller, M₈Conducting, first order boost conversion circuit Induction charging loop can turn on, first order circuit can realize boost function with normal work；By changing switching pulse Dutycycle can change output voltage, as output voltage V_outRise, passes through level shift circuit M₁Drain potential increase, so The second level switching pulse level that M1 drains exported, which is raised, causes M₁₀It can open, second level booster circuit is started working, together When V_outRise causes M₄Side electric current increase, M₂Drain-source pressure drop increase, M₈Grid potential is reduced, M₈It is turned off, such first order is opened Close branch road to be turned off, reduce power loss.

Above circuit can cause circuit boost no-load voltage ratio less or during circuit start using the work of first order circuit, defeated Go out after voltage rise to start the work of second level booster circuit and obtain high output voltage, using level shift circuit so that switching signal Increase, it is ensured that the M of high threshold voltage₁₀It can be worked with normal table.

Claims (5)

1. a kind of promotion buckling is than DC boosting translation circuit, it is characterized in that：The circuit includes first order booster circuit 110, Second level booster circuit 130, level shift circuit 120, breaking circuit 140；Inductance L in 110 circuits₁With input voltage V_inConnection Side simultaneously with transistor M in 140 circuits₂With transistor M₃Drain electrode and 130 circuits in inductance L₂With input voltage V_inEven The side connection connect；Transistor M in 110 circuits₈Grid and 140 circuits in transistor M₂Source electrode connection；In 110 circuits Transistor M₉Grid and 120 circuits in transistor M₁Grid and switching control pulse connection；Diode D in 110 circuits₁、 Electric capacity C₁And load resistance R_LCommon port and 130 circuits in inductance L₃Not with diode D₂The side of connection and 140 electricity Transistor M in road₄Grid connection；Transistor M in 120 circuits₁Drain electrode and 130 circuits in transistor M₁₀Grid connection.

2. promotion buckling according to claim 1 is than DC boosting translation circuit, it is characterized in that：The first order boosting electricity The inductance L on road 110₁Side is connected with input voltage, opposite side and switching branches and diode D₁Positive pole connection；Switching branches By two transistor M₈With M₉Cascade, wherein transistor M₉Grid connecting valve control wave, transistor M₉Drain electrode with Transistor M₈Source electrode connection, transistor M₈The cut-off signals V that exports of grid and breaking circuit 140_sw1Connection, transistor M₈'s Drain electrode and inductance L₁With diode D₁Common port connection；Diode D₁Negative pole and output capacitance C₁With resistance R_LOne it is public End connection, output capacitance C₁With load resistance R_LParallel connection, another common end grounding.

3. promotion buckling according to claim 1 is than DC boosting translation circuit, it is characterized in that：The breaking circuit 140 Including by transistor M₄With M₅The differential pair of composition, M₄With M₅Source electrode and transistor M₆Drain electrode connection, M₆For tail current source；It is brilliant Body pipe M₂With M₃Grid and drain electrode short circuit, M₂With M₃Drain electrode meet input voltage V_in, M₄Grid meet load resistance RL, M₇Source Pole is grounded, M₇Drain electrode and load resistance R₂Connection, M₂Source electrode and M₇Load resistance R₂The voltage of the common port connected is The cut-off signals V of output_SW1, M₅、M₆、M₇Grid voltage meet bias voltage V respectively_B1、V_B3、V_B2。

4. promotion buckling according to claim 1 is than DC boosting translation circuit, it is characterized in that：The second level boosting electricity Road 130 includes inductance L₂, transistor M₁₀, diode D₂, electric capacity C₂, inductance L₃；Inductance L₂Side is connected with input voltage, in addition Side and transistor M₁₀Drain electrode connection, transistor M₁₀Grid and 120 circuits in M₁Drain electrode connection, M₁₀Source ground； Diode D₂Positive pole and M₁₀Drain electrode connection, diode D₂Negative pole and electric capacity C₂Connection, inductance L₃Side and electric capacity C₂Connection, Other side connection load resistance R_L。

5. promotion buckling according to claim 1 is than DC boosting translation circuit, it is characterized in that：The level shift circuit 120 include transistor M₁With resistance R₁, wherein M₁Grid connecting valve pulse signal, resistance R₁Side and M₁Drain electrode connection, Resistance R₁Other side and load resistance R_LConnection.