CN204481769U - A kind of D-type power amplifier protective circuit - Google Patents
A kind of D-type power amplifier protective circuit Download PDFInfo
- Publication number
- CN204481769U CN204481769U CN201520022257.7U CN201520022257U CN204481769U CN 204481769 U CN204481769 U CN 204481769U CN 201520022257 U CN201520022257 U CN 201520022257U CN 204481769 U CN204481769 U CN 204481769U
- Authority
- CN
- China
- Prior art keywords
- pin
- power
- power amplifier
- electric capacity
- type
- 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.)
- Expired - Fee Related
Links
Abstract
A kind of D-type power amplifier protective circuit; include PWM input and load; also include power amplifier driver module, power stage and sampling module and comparison module; the input of described power amplifier driver module inputs with PWM and is connected; described power stage is connected with the output of power amplifier driver module with the input of sampling module; described power stage is connected with load with the output of sampling module, and the input of described comparison module is connected with sampling module, power amplifier driver module with power stage respectively with output.The utility model is in the high-power driving of D-type power amplifier uses, and protected effect is particularly remarkable.When power amplifier exports overpower, during junction temperature overrate, protective circuit immediately can action, and make the circuit quick closedown of power amplifier driver module, power amplifier power stage reduces to zero, reaches fast, the object of real-time guard power amplifier.And this circuit has structure simply, practical, the features such as fast response time.
Description
Technical field
The present invention relates to a kind of D-type power amplifier protective circuit.
Background technology
Class-D amplifier in power amplifier, because its output stage field effect transistor (power MOSFET) most of the time is in saturation conduction and cut-off state, therefore power loss is smaller, and efficiency can reach more than 90%, there is not the features such as intermodulation distortion, be thus widely adopted.Along with the power output of power amplifier is increasing, power MOSFET is wherein also towards high-power future development.But the power of power MOSFET does larger, the heat generation density of whole device is higher.Under higher dissipation power effect, if the heat-sinking capability of power MOSFET is limited, power MOSFET inside chip will be made to raise because of junction temperature; drain current increases; exceed its maximum rated power, and cause damage phenomenon, thus most important to the power MOSFET protection in power amplifier.
Existing power amplifier protection circuit has several below: overvoltage, overcurrent, excess temperature, blown fuse etc., but the problem such as these safeguard measures all exist reaction not in time, protective circuit slow motion.Due to the difference in operate time of protection, do not reach protection power MOSFET on the contrary not by the object of burning.
Summary of the invention
The technical problem to be solved in the present invention is: for the problem of prior art intermediate power amplifier protective circuit slow motion, provides a kind of D-type power amplifier protective circuit.
The technical solution adopted in the present invention is: a kind of D-type power amplifier protective circuit; include PWM input and load; also include power amplifier driver module, power stage and sampling module and comparison module; the input of described power amplifier driver module inputs with PWM and is connected; described power stage is connected with the output of power amplifier driver module with the input of sampling module; described power stage is connected with load with the output of sampling module, and the input of described comparison module is connected with sampling module, power amplifier driver module with power stage respectively with output.
PWM input signal wherein after modulation inputs from power amplifier driver module, be separated through power amplifier driver module and export PWM1, PWM2 drive singal, these two signal driving powers export and the power MOSFET in sampling module, make power output after power MOSFET ON.When power MOSFET is in conducting state, drain current I
dat the conducting resistance R of drain-source interpolar
ds (on)upper generation drain voltage V
ds; After power amplifier power exports continuously, power MOSFET junction temperature T
jto continue to rise, then its corresponding conducting resistance R
ds (on)also increase thereupon, and the junction temperature T of conducting resistance and power MOSFET
jbetween linear; By sample circuit by will the voltage V of junction temperature be exceeded on power stage and sampling module
ds' sample, this sampling voltage V
dsthe in-phase input end of ' input comparison module circuit; by comparison module circuit, sampling voltage and reference voltage (in junction temperature allowed band) are compared again; its result exports as control signal SD; by the Enable Pin SD of feedback control for networked control power amplifier driver module circuit; cut out drive circuit outputs signal; power amplifier power output MOSFET is ended, and power amplifier power stage drops to zero, thus reaches the object of protection power amplifier fast.
Described power amplifier driver module circuit is made up of 74HC00 type high speed NAND gate chip U7, power MOSFET special I R2113S type driving chip U9, diode D4, resistance R11, electric capacity C17, C24, C25; Wherein the signal of PWM input inputs from the 74HC00 type high speed NAND gate chip U712 pin of high speed NAND gate chip U7,13 pin and 12 pin phase short circuits, 12 pin are pulled in the working power of+5V by resistance R11 simultaneously, 74HC00 type high speed NAND gate chip U7 output pin 11 is connected with 14 pin of IR2113S type driving chip U9 with 1,2 pin of 74HC00 type high speed NAND gate chip U7 simultaneously, wherein 1 and 2 pin interconnection of 74HC00 type high speed NAND gate chip U7; 3 pin of 74HC00 type high speed NAND gate chip U7 are connected to 12 pin of IR2113S type driving chip U9.12 pin of IR2113S type driving chip U9 are high input HIN, and 14 pin are low input LIN, and 1 pin is low output LO, and export PWM2 drive singal, 2 pin are earth terminal, and 3 pin are the underarm gate bias voltage of bridge-type power output MOSFET, are+12V; 6 pin are holding of power output MOSFET floatingly, 7 is the upper arm gate bias voltage of bridge-type power output MOSFET, 8 pin are high output terminal HO, export PWM1 drive singal, 11 pin are the working power+5V of IR2113S type driving chip U9,15 pin are earth terminal, and 13 is the Enable Pin (meeting control signal SD) of IR2113S type driving chip U9, control closedown that driving chip signal exports or open.When this Enable Pin input high level, namely driver closes, and the high and low output of driver is zero (namely exporting without drive singal); Electric capacity C17, C25 are filter capacitor, wherein electric capacity C17 one end ground connection, another termination+5V working power, and electric capacity C25 one end ground connection, 3 pin+the 12V of another termination IR2113S type driving chip U9,3 pin of the positive termination IR2113S of diode D4, one end of its negative pole and electric capacity C24 connects 7 pin of IR2113S type driving chip U9 simultaneously, for the upper arm grid of bridge-type power output MOSFET provides bias voltage.The other end ground connection of electric capacity C24, C24 is bootstrap capacitor.
Described power stage and sampling module are by Q4, Q5 of IRFB4019PBF power MOSFET, and resistance R21, R22, electric capacity C23, C26 form.The PWM drive singal exported by power amplifier driver module, is separated into PWM1 input and PWM2 inputs two tunnels, and be connected to the grid of power MOSFET Q4, the Q5 in bridge-type power amplifier respectively, the drain electrode of Q4 connects+48V power supply, and its source electrode connects to be held floatingly.The drain electrode of Q5 connects holds floatingly, its source ground end.The source S of the one termination Q4 of resistance R21, the other end is connected with electric capacity C23, another termination+48V power supply of electric capacity C23; The drain D of the one termination Q5 of resistance R22, the other end is connected with electric capacity C26, the other end ground connection of electric capacity C26.Bridge drive circuit, with contrary phase driven two power MOSFETs, controls it with corresponding frequency saturation conduction or cut-off, another cut-off when making a power MOSFET conducting.Adopting PWM mode to drive is to make power MOSFET change operating state as much as possible, reduces the time that it is in linear amplification region, thus reduces thermal losses, raises the efficiency; Sample circuit carries out voltage sampling from the Q5 power MOFET drain-source interpolar the circuit of power stage and sampling module.By the conducting resistance R of excess temperature power MOSFET
ds (on)be equivalent to R
ds+ Δ R, wherein R
dsfor conducting resistance during power MOSFET permission junction temperature, and Δ R exceedes the conducting resistance increment allowing junction temperature.The heat-sinking capability of power MOSFET device represents by thermal resistance usually, and thermal resistance is less, then heat-sinking capability is better; Thermal resistance is larger, then represent that heat transfer is more difficult, the heat that power MOSFET produces is higher, so can judge the febrile state of power MOSFET according to the size of thermal resistance value; Because power consumption is the immediate cause producing heat, the power mosfet chip that power consumption is large, caloric value is also certain large; Therefore, in the Q5 conducting of power amplifier output, when power amplifier power normally exports, the drain-source electrode resistance R of Q5
ds (on)on flow through rated current I
d, produce drain voltage V simultaneously
ds; After power amplifier power exports continuously, its junction temperature T
jwhen being increased over rated value, conducting resistance R
ds (on)also increase (R with drain current simultaneously
dsand I
dbecome R
ds+ Δ R and I
d'), cause power consumption greatly to increase, the drain voltage V of Q5
dsalso V is increased to
ds'.Therefore by this drain voltage V
ds' sample, as the control signal of protection power amplifier.
The circuit of described comparison module is made up of operational amplifier LM324, resistance R1, R2, R3, electric capacity C1.4 pin of operational amplifier LM324 meet power supply+12V, meet electric capacity C1 simultaneously, the 11 pin ground connection of U1, and inverting input 2 pin connecting resistance R2, another pin of R2 connects reference voltage V
ds, in-phase input end 3 pin of operational amplifier LM324 meets sampling voltage V through resistance R1
ds', output 1 pin of U1 meets control signal SD through resistance R3, another pin ground connection of electric capacity C1.Power MOSFET will exceed the conducting resistance R of junction temperature state
ds (on)upper voltage V
ds' as sampled signal, input to the in-phase input end of comparator, by comparator using drain voltage (as the reference voltage) V in the normal control range of junction temperature on this voltage and power MOSFET
dscompare, comparative result exports the control signal SD as power amplifier protection.As overheated in power MOSFET (having exceeded junction temperature); then the circuit of comparison module exports high level; control IR2113S type driving chip U9 Enable Pin (SD) of power amplifier driver module; power amplifier driver is closed; the power MOSFET of power amplifier output stage is ended; power amplifier exports and is down to zero, reaches the object of protection power amplifier fast.If power amplifier junction temperature is in normal control range, the circuit then output low level of comparison module, makes power amplifier continue power output.
The invention has the beneficial effects as follows: the present invention is in the high-power driving of D-type power amplifier uses, and protected effect is particularly remarkable.When power amplifier exports overpower, during junction temperature overrate, protective circuit immediately can action, and make the circuit quick closedown of power amplifier driver module, power amplifier power stage reduces to zero, reaches fast, the object of real-time guard power amplifier.And this circuit has structure simply, practical, the features such as fast response time.
Accompanying drawing explanation
Fig. 1 is electric theory diagram of the present invention.
Fig. 2 is power amplifier driver module 1 electrical schematic diagram of the present invention.
Fig. 3 is power stage of the present invention and sampling module 2 electrical schematic diagram.
Fig. 4 is comparison module 3 electrical schematic diagram of the present invention.
Fig. 5 is power amplifier electrical schematic diagram of the present invention.
Embodiment
As shown in Figure 1; a kind of D-type power amplifier protective circuit described in the present embodiment; include PWM input and load; also include power amplifier driver module 1, power stage and sampling module 2 and comparison module 3; the input of described power amplifier driver module inputs with PWM and is connected; described power stage is connected with the output of power amplifier driver module with the input of sampling module; described power stage is connected with load with the output of sampling module, and the input of described comparison module is connected with sampling module, power amplifier driver module with power stage respectively with output.
PWM input signal wherein after modulation inputs from power amplifier driver module, be separated through power amplifier driver module and export PWM1, PWM2 drive singal, these two signal driving powers export and the power MOSFET in sampling module, make power output after power MOSFET ON.When power MOSFET is in conducting state, drain current I
dat the conducting resistance R of drain-source interpolar
ds (on)upper generation drain voltage V
ds; After power amplifier power exports continuously, power MOSFET junction temperature T
jto continue to rise, then its corresponding conducting resistance R
ds (on)also increase thereupon, and the junction temperature T of conducting resistance and power MOSFET
jbetween linear; By sample circuit by will the voltage V of junction temperature be exceeded on power stage and sampling module
ds' sample, this sampling voltage V
dsthe in-phase input end of ' input comparison module circuit; by comparison module circuit, sampling voltage and reference voltage (in junction temperature allowed band) are compared again; its result exports as control signal SD; by the Enable Pin SD of feedback control for networked control power amplifier driver module circuit; cut out drive circuit outputs signal; power amplifier power output MOSFET is ended, and power amplifier power stage drops to zero, thus reaches the object of protection power amplifier fast.
Described power amplifier driver module is made up of 74HC00 type high speed NAND gate chip U7, power MOSFET special I R2113S type driving chip U9, diode D4, resistance R11, electric capacity C17, C24, C25; Wherein the signal of PWM input inputs from the 74HC00 type high speed NAND gate chip U712 pin of high speed NAND gate chip U7,13 pin and 12 pin phase short circuits, 12 pin are pulled in the working power of+5V by resistance R11 simultaneously, 74HC00 type high speed NAND gate chip U7 output pin 11 is connected with 14 pin of IR2113S type driving chip U9 with 12 pin of 74HC00 type high speed NAND gate chip U7 simultaneously, wherein 1 and 2 pin interconnection of 74HC00 type high speed NAND gate chip U7; 3 pin of 74HC00 type high speed NAND gate chip U7 are connected to 12 pin of IR2113S type driving chip U9.12 pin of IR2113S type driving chip U9 are high input HIN, and 14 pin are low input LIN, and 1 pin is low output LO, and export PWM2 drive singal, 2 pin are earth terminal, and 3 pin are the underarm gate bias voltage of bridge-type power output MOSFET, are+12V; 6 pin are holding of power output MOSFET floatingly, 7 is the upper arm gate bias voltage of bridge-type power output MOSFET, 8 pin are high output terminal HO, export PWM1 drive singal, 11 pin are the working power+5V of IR2113S type driving chip U9,15 pin are earth terminal, and 13 is the Enable Pin (meeting control signal SD) of IR2113S type driving chip U9, control closedown that driving chip signal exports or open.When this Enable Pin input high level, namely driver closes, and the high and low output of driver is zero (namely exporting without drive singal); Electric capacity C17, C25 are filter capacitor, wherein electric capacity C17 one end ground connection, another termination+5V working power, and electric capacity C25 one end ground connection, 3 pin+the 12V of another termination IR2113S type driving chip U9,3 pin of the positive termination IR2113S of diode D4, one end of its negative pole and electric capacity C24 connects 7 pin of IR2113S type driving chip U9 simultaneously, for the upper arm grid of bridge-type power output MOSFET provides bias voltage.The other end ground connection of electric capacity C24, C24 is bootstrap capacitor.
Described power stage and sampling module circuit are by Q4, Q5 of IRFB4019PBF power MOSFET, and resistance R21, R22, electric capacity C23, C26 form.The PWM drive singal exported by power amplifier driver module, is separated into PWM1 input and PWM2 inputs two tunnels, and be connected to the grid of power MOSFET Q4, the Q5 in bridge-type power amplifier respectively, the drain electrode of Q4 connects+48V power supply, and its source electrode connects to be held floatingly.The drain electrode of Q5 connects holds floatingly, its source ground end.The source S of the one termination Q4 of resistance R21, the other end is connected with electric capacity C23, another termination+48V power supply of electric capacity C23; The drain D of the one termination Q5 of resistance R22, the other end is connected with electric capacity C26, the other end ground connection of electric capacity C26.Bridge drive circuit, with contrary phase driven two power MOSFETs, controls it with corresponding frequency saturation conduction or cut-off, another cut-off when making a power MOSFET conducting.Adopting PWM mode to drive is to make power MOSFET change operating state as much as possible, reduces the time that it is in linear amplification region, thus reduces thermal losses, raises the efficiency; Sample circuit carries out voltage sampling from the Q5 power MOFET drain-source interpolar the circuit of power stage and sampling module.By the conducting resistance R of excess temperature power MOSFET
ds (on)be equivalent to R
ds+ Δ R, wherein R
dsfor conducting resistance during power MOSFET permission junction temperature, and Δ R exceedes the conducting resistance increment allowing junction temperature.The heat-sinking capability of power MOSFET device represents by thermal resistance usually, and thermal resistance is less, then heat-sinking capability is better; Thermal resistance is larger, then represent that heat transfer is more difficult, the heat that power MOSFET produces is higher, so can judge the febrile state of power MOSFET according to the size of thermal resistance value; Because power consumption is the immediate cause producing heat, the power mosfet chip that power consumption is large, caloric value is also certain large; Therefore, in the Q5 conducting of power amplifier output, when power amplifier power normally exports, the drain-source electrode resistance R of Q5
ds (on)on flow through rated current I
d, produce drain voltage V simultaneously
ds; After power amplifier power exports continuously, its junction temperature T
jwhen being increased over rated value, conducting resistance R
ds (on)also increase (R with drain current simultaneously
dsand I
dbecome R
ds+ Δ R and I
d'), cause power consumption greatly to increase, the drain voltage V of Q5
dsalso V is increased to
ds'.Therefore by this drain voltage V
ds' sample, as the control signal of protection power amplifier.
The circuit of described comparison module is made up of operational amplifier LM324, resistance R1, R2, R3, electric capacity C1.4 pin of operational amplifier LM324 meet power supply+12V, meet electric capacity C1 simultaneously, the 11 pin ground connection of U1, and inverting input 2 pin connecting resistance R2, another pin of R2 connects reference voltage V
ds, in-phase input end 3 pin of operational amplifier LM324 meets sampling voltage V through resistance R1
ds', output 1 pin of U1 meets control signal SD through resistance R3, another pin ground connection of electric capacity C1.Power MOSFET will exceed the conducting resistance R of junction temperature state
ds (on)upper voltage V
ds' as sampled signal, input to the in-phase input end of comparator, by comparator using drain voltage (as the reference voltage) V in the normal control range of junction temperature on this voltage and power MOSFET
dscompare, comparative result exports the control signal SD as power amplifier protection.As overheated in power MOSFET (having exceeded junction temperature); then the circuit of comparison module exports high level; control IR2113S type driving chip U9 Enable Pin (SD) of power amplifier driver module; power amplifier driver is closed; the power MOSFET of power amplifier output stage is ended; power amplifier exports and is down to zero, reaches the object of protection power amplifier fast.If power amplifier junction temperature is in normal control range, the circuit then output low level of comparison module, makes power amplifier continue power output.
As shown in Figure 5, be the circuit theory diagrams of the D-type power amplifier described in the present embodiment and fast protection circuit thereof.
The present invention makes the reliability of power amplifier greatly improve, and circuit is simple and reliable, protection speed is fast, the demand that the high-power driving that can meet power amplifier completely exports.
Above-mentioned explanation is not restricted to institute of the present invention, and only used D-type power amplifier in example of the present invention, the power MOSFET in the power amplifier of other type, power BJT, IGBT etc. are suitable for the present invention too.Therefore the present invention is not limited to above-mentioned citing, those skilled in the art, within the scope of the invention, the change made, all should belong to protection scope of the present invention.
Claims (4)
1. a D-type power amplifier protective circuit; include PWM input and load; it is characterized in that: also include power amplifier driver module, power stage and sampling module and comparison module; the input of described power amplifier driver module inputs with PWM and is connected; described power stage is connected with the output of power amplifier driver module with the input of sampling module; described power stage is connected with load with the output of sampling module, and the input of described comparison module is connected with sampling module, power amplifier driver module with power stage respectively with output.
2. a kind of D-type power amplifier protective circuit according to claim 1, is characterized in that: described power amplifier driver module circuit is made up of 74HC00 type high speed NAND gate chip U7, power MOSFET special I R2113S type driving chip U9, diode D4, resistance R11, electric capacity C17, C24, C25; Wherein the signal of PWM input inputs from the 74HC00 type high speed NAND gate chip U712 pin of high speed NAND gate chip U7,13 pin and 12 pin phase short circuits, 12 pin are pulled in the working power of+5V by resistance R11 simultaneously, 74HC00 type high speed NAND gate chip U7 output pin 11 is connected with 14 pin of IR2113S type driving chip U9 with 1,2 pin of 74HC00 type high speed NAND gate chip U7 simultaneously, wherein 1 and 2 pin interconnection of 74HC00 type high speed NAND gate chip U7; 3 pin of 74HC00 type high speed NAND gate chip U7 are connected to 12 pin of IR2113S type driving chip U9; 12 pin of IR2113S type driving chip U9 are high input HIN, and 14 pin are low input LIN, and 1 pin is low output L0, and export PWM2 drive singal, 2 pin are earth terminal, and 3 pin are the underarm gate bias voltage of bridge-type power output MOSFET, are+12V; 6 pin are holding of power output MOSFET floatingly, 7 is the upper arm gate bias voltage of bridge-type power output MOSFET, 8 pin are high output terminal H0, export PWM1 drive singal, 11 pin are the working power+5V of IR2113S type driving chip U9,15 pin are earth terminal, and 13 is the Enable Pin of IR2113S type driving chip U9; Electric capacity C17, C25 are filter capacitor, wherein electric capacity C17 one end ground connection, another termination+5V working power, and electric capacity C25 one end ground connection, 3 pin+the 12V of another termination IR2113S type driving chip U9,3 pin of the positive termination IR2113S of diode D4, one end of its negative pole and electric capacity C24 connects 7 pin of IR2113S type driving chip U9 simultaneously; The other end ground connection of electric capacity C24, C24 is bootstrap capacitor.
3. a kind of D-type power amplifier protective circuit according to claim 2, is characterized in that: described power stage and sampling module by Q4, Q5 of IRFB4019PBF power MOSFET, resistance R21, R22, electric capacity C23, C26 form; The PWM drive singal exported by power amplifier driver module, is separated into PWM1 input and PWM2 inputs two tunnels, and be connected to the grid of power MOSFET Q4, the Q5 in bridge-type power amplifier respectively, the drain electrode of Q4 connects+48V power supply, and its source electrode connects to be held floatingly; The drain electrode of Q5 connects holds floatingly, its source ground end; The source S of the one termination Q4 of resistance R21, the other end is connected with electric capacity C23, another termination+48V power supply of electric capacity C23; The drain D of the one termination Q5 of resistance R22, the other end is connected with electric capacity C26, the other end ground connection of electric capacity C26.
4. a kind of D-type power amplifier protective circuit according to claim 3, is characterized in that: the circuit of described comparison module is made up of operational amplifier LM324, resistance R1, R2, R3, electric capacity C1; 4 pin of operational amplifier LM324 meet power supply+12V, meet electric capacity C1 simultaneously, the 11 pin ground connection of U1, and inverting input 2 pin connecting resistance R2, another pin of R2 connects reference voltage V
ds, in-phase input end 3 pin of operational amplifier LM324 meets sampling voltage V through resistance R1
ds', output 1 pin of U1 meets control signal SD through resistance R3, another pin ground connection of electric capacity C1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520022257.7U CN204481769U (en) | 2015-01-12 | 2015-01-12 | A kind of D-type power amplifier protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520022257.7U CN204481769U (en) | 2015-01-12 | 2015-01-12 | A kind of D-type power amplifier protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204481769U true CN204481769U (en) | 2015-07-15 |
Family
ID=53637540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520022257.7U Expired - Fee Related CN204481769U (en) | 2015-01-12 | 2015-01-12 | A kind of D-type power amplifier protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204481769U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108566185A (en) * | 2018-06-07 | 2018-09-21 | 河北新华北集成电路有限公司 | A kind of power tube drive circuit and driver |
-
2015
- 2015-01-12 CN CN201520022257.7U patent/CN204481769U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108566185A (en) * | 2018-06-07 | 2018-09-21 | 河北新华北集成电路有限公司 | A kind of power tube drive circuit and driver |
| CN108566185B (en) * | 2018-06-07 | 2022-04-26 | 河北新华北集成电路有限公司 | Power tube driving circuit and driver |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103390877A (en) | Overcurrent detection and protection circuit | |
| CN203516159U (en) | Radiating fan control circuit and electronic equipment | |
| CN105846665B (en) | A kind of normal open type SiC JFET driving circuit with self-protection function | |
| CN204481769U (en) | A kind of D-type power amplifier protective circuit | |
| CN205249042U (en) | Reduce switching power supply input impulse current's circuit | |
| CN209462046U (en) | USB interface protects circuit and USB charging interface | |
| CN204103885U (en) | Boostrap circuit, inverter and air conditioner | |
| CN104639056A (en) | Rapid protecting circuit for power amplifier | |
| CN201349201Y (en) | Temperature gain control circuit applied to audio-frequency amplifier | |
| CN203288934U (en) | Low-power semiconductor laser drive circuit | |
| CN107093886A (en) | It is a kind of to be embedded in solar powered network from the voltage security power supply circuit become in device | |
| CN209282887U (en) | A kind of battery management protective device | |
| CN207664602U (en) | Low-power consumption short-circuit protection circuit for DC/DC converters | |
| CN207691412U (en) | A kind of thermal-shutdown circuit of LED drive power | |
| CN208707612U (en) | A kind of load switch control circuit | |
| CN205811519U (en) | A kind of vehicle-mounted overload protecting circuit having brush fan controlled based on PWM | |
| CN108683416A (en) | A kind of load switch control circuit | |
| CN202998532U (en) | Electromagnetic induction heating control circuit based on digital signal processing | |
| CN204851729U (en) | A PWM fan control circuit for refrigerator | |
| CN100490265C (en) | Electric current driving electronic broken circuit protecting equipment | |
| CN204538661U (en) | A kind of for the overheating protection circuit in power management chip | |
| CN104406273A (en) | Protective circuit of central air-conditioning cooling fan | |
| CN105116804A (en) | Negative-logical IGBT/MOSFET driving circuit, driving system and driving method, and air conditioner | |
| CN109728802A (en) | A kind of double power supply circuit with timing applied to millimeter wave chip | |
| CN205039794U (en) | Solid state relay with energy recuperation utilization function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150715 Termination date: 20190112 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |