204results about How to "Increased shutdown speed" patented technology

The invention provides a heterojunction carbon nano-tube field effect transistor of which a subthreshold swing is smaller than 60 millivolt/magnitude in the room temperature and a preparation method thereof. The device uses the semiconductor carbon nano-tube as the active layer, the heterojunction formed by the graphene layer and the semiconductor carbon nano-tube is used as the source end of the device, the gate medium and the gate electrode modulate the carbon nano-tube channel and the graphene/carbon nano-tube junction at the same time, so that the turn-off of the transistor is accelerated by using the character that the graphene/carbon nano-tube junction barrier is modulated by the gate voltage. The transistor can control the polarity through the selection of the source-drain metal, namely the metal of high power function is used as the source-drain electrode for realizing the p-type field effect transistor, and the metal of low power function is used as the source-drain electrode for realizing the n-type field effect transistor.

The invention discloses an isolated drive circuit of a DC converter, which relates to technical field of circuit drive. The isolated drive circuit of the DC converter comprises: an isolated transformer, a primary winding, a primary winding drive circuit, a first secondary winding and a second secondary winding whose same name ends are opposite, and a first switch pipe and a second switch pipe; the different name end of the first secondary winding is connected with source electrode of the first switch pipe, the same name end is connected with the drain electrode of the first switch pipe through a first resistance, the different name end of the first secondary winding is connected with the grid electrode of the first switch pipe through a first diode; the different name end of the first secondary winding is connected with the anode of the first diode; the same name end of the second secondary winding is connected with the source electrode of the second switch pipe, the different name end is connected with the drain electrode of the second switch pipe through a second resistance, the same name end of the second secondary winding is connected with the grid electrode of the second switch pipe through a second diode; the same name end of the second secondary winding is connected with the anode of the second diode. The whole circuit has simple topology, high reliability, can be used for many occasions flexibly.

The invention generally relates to a lateral power semiconductor transistor for example in integrated circuits. In particular the invention relates to Lateral Insulated Gate Bipolar Transistors or other lateral bipolar devices such as PIN diodes. The invention also generally relates to a method of increasing switching speed of a lateral bipolar power semiconductor transistor. There is provided a lateral bipolar power semiconductor transistor comprising a first floating semiconductor region of the first conductivity type located laterally spaced to an anode/drain region and a second floating semiconductor region of the second conductivity type located laterally adjacent the first floating semiconductor region, and a floating electrode placed above and in direct contact to the first and second floating semiconductor regions.

The invention discloses a synchronous rectification controller and a synchronous rectification control method. The controller comprises a sampling module, a driving module and a control module, wherein the sampling module is used for sampling a source voltage and a drain voltage of a synchronous rectification metal-oxide-semiconductor (MOS) tube and acquiring a voltage difference value between thesource voltage and the drain voltage, the driving module is used for adjusting a grid voltage of the tube, and the control module is used for comparing the voltage difference value, a first thresholdvalue and a second threshold value, controlling the driving module to adjust the grid voltage of the tube to maximum output voltage when the voltage difference value is smaller than the first threshold value, controlling the driving module to adjust the grid voltage of the tube to change between 0 and the maximum output voltage when the voltage difference value is larger than the first thresholdvalue and smaller than the second threshold value so that the voltage difference value is adjusted to be equal to the first threshold value, and controlling the driving module to adjust the grid voltage of the tube to 0 when the voltage difference value is larger than the second threshold value. By the controller, the switch-on and switch-off speed of the synchronous rectification MOS tube can beincreased, so that the efficiency is obviously improved, and the loss is obviously reduced.

The invention belongs to the technical field of a semiconductor power device, and specifically relates to a lateral insulated gate bipolar transistor. On the basis of a conventional positive electrode short circuit LIGBT structure, an isolation dielectric groove is formed in one end of a collector in a device drift region; an integrated PMOS structure is formed at the other end of the isolation dielectric groove, and the integrated PMOS structure is connected with a positive electrode short circuit N+ region in series; and meanwhile, an integrated capacitive structure is introduced between the gate of the integrated PMOS structure and the emitter of the LIGBT device. By virtue of a self-biasing effect formed by the integrated PMOS structure and the capacitor, the lateral insulated gate bipolar transistor has the same working condition as the conventional LIGBT and the same conduction voltage drop, without causing a negative impedance phenomenon in the conduction process, in the conduction state; in a blocking state, the lateral insulated gate bipolar transistor has higher breakdown voltage; and meanwhile, in the switching-off process, the lateral insulated gate bipolar transistor has higher switching-off speed and lower switching-off loss.

The invention relates to a high-power MOSFET driving circuit. PWM input signals pass through a hardware deadzone circuit, a pulse blocking circuit, an optical coupling isolation circuit and a peripheral circuit in sequence to generate the gate drive signals of the Mosfet of an upper bridge arm and the Mosfet of a lower bridge arm, the hardware deadzone circuit generates hardware deadzone time, the pulse blocking circuit is used for blocking pulse signals when a protection state occurs, the hardware deadzone circuit, the optical coupling isolation circuit, the peripheral circuit and a bootstrap circuit are combined to form the high-power MOSFET driving circuit used for driving the high-power Mosfets, and the measure of additionally installing the bootstrap circuit is taken to prevent the Mosfet gate-to-source voltage of the upper bridge arm from floating. The turn-on and turn-off speed of the Mosfets is improved, and therefore the turn-on and turn-off losses of the Mosfets are reduced. A blocking and judging circuit is used for blocking drive of hardware, and therefore the Mosfets are protected, the driving capacity of the driving circuit is improved, the work efficiency of the circuit is improved, and therefore cost is lowered.

The invention belongs to the technical field of power semiconductors, and particularly relates to a self-adaptive SOI LIGBT device. Compared with a traditional structure, the self-adaptive NMOS structure is introduced into the collector electrode end, and a Zener diode structure is introduced into the emitter electrode end. During forward conduction, the NMOS channel at the collector end is closed, an electron extraction path at the collector end is blocked to eliminate the voltage turn-back effect, and at the moment, the Zener diode is reversely biased but is not broken down, and holes storedin the drift region cannot be extracted, so that the new device can obtain low forward conduction voltage drop. In the turn-off process, along with rise of collector voltage, the collector NMOS channel is adaptively opened to form the electron extraction path, the Zener diode is reversely broken down and conducted to extract an emitter end hole, and the NMOS channel and the Zener diode accelerateturn off of the device to reduce the turn-off loss; and in a short-circuit state, the Zener diode is reversely broken down and conducted, so that the saturation current density can be reduced to improve the short-circuit resistance. Therefore, the device has smaller conduction voltage drop and turn-off loss, and a wider safety working area.

The invention belongs to the technical field of power semiconductors, and specifically relates to an SOI LIGBT with a controllable collector trough. Compared with a conventional structure, the LIGBT mainly introduces a controllable collector trough structure to a collector end and introduces a plurality of trough grid structures to the collector. During the forwarding conduction, the bias voltage of a trough collector relative to the collector is negative, and a side wall of the collector trough forms a high-density P-type reflection layer so as to increase the hole implantation. The segmented trough grid structures serve as the blocking layers of hole extraction. Therefore, the increase of the hole/electron concentration in a drift region facilitates the obtaining of a lower forwarding conduction voltage drop. Meanwhile, because an N+ collector region is located on the upper surface of a P+ collector region and does not make contact with an N-type drift region, a new device does not has a voltage turning-back effect. The beneficial effects of the invention are that the LIGBT, compared with a conventional short-circuit anode-LIGBT structure, is higher in switching-off speed and lower in forwarding conduction voltage drop, and does not have the voltage turning-back effect.

The invention discloses a synchronous rectification control circuit, an isolated power supply conversion circuit and a control method, the synchronous rectification control circuit can be coupled witha synchronous rectification transistor and can send a control signal to the synchronous rectification transistor; the synchronous rectification control circuit comprises a comparison circuit, a drivecircuit, a signal adjusting circuit and a conduction voltage drop adjusting circuit. The input end of the comparison circuit is respectively coupled with the synchronous rectification transistor andat least one reference signal, and the output end of the comparison circuit is respectively coupled with the drive circuit and the signal conditioning circuit; the output end of the drive circuit is coupled with the synchronous rectification transistor and used for sending a control signal to the synchronous rectification transistor according to the signal output by the comparison circuit; the output end of the signal adjusting circuit is coupled with the comparison circuit and used for adjusting a set reference signal in the at least one reference signal according to the signal output by thecomparison circuit. According to the invention, accurate turn-off of the synchronous rectification transistor can be realized, the turn-off speed can be improved, and the reliability of the circuit isimproved.

The invention discloses an IGBT device drive circuit and method capable of reducing the turn-off loss. The circuit comprises a detection module, a current drive module, a comparison module and a logic control module, wherein an input end of the logic control module is used for connecting external pulse width modulation signal and digital bit selection signal; a feedback end of the logic control module is connected with an output end of the comparison module; the input end of the current drive module is connected with the output end of the logic control module; the output end of the current drive module is used for being connected to a control end of an IGBT device; the input end of the detection module is used for being connected with the output end of the IGBT device; and the output end of the detection module is connected to the input end of the comparison module. According to the IGBT device drive circuit and method, the turn-off power loss of the IGBT device can be reduced; the device is prevented from being burnt by current and voltage overshoots caused by turn-off; meanwhile, output voltage and current of the drive circuit can be accurately controlled; the turn-off speed is increased while the turn-off overshoot voltage of the IGBT is not increased; the signal delay is relatively small; and the condition that a feedback circuit of the drive module normally works within short turn-off time of the IGBT device can be ensured.

The invention discloses a closed-loop control circuit for a power switching device and a method. The closed-loop control circuit comprises a voltage differential circuit, a comparator circuit, a delay circuit and a current driving circuit, wherein the first input end of the comparator circuit is connected with the output end of the voltage differential circuit; the second input end of the comparator circuit is used for being connected with reference voltage; the input end of the delay circuit is connected with the output end of the comparator circuit; the first input end of the current driving circuit is connected with the output end of the delay circuit; the second input end of the current driving circuit receives PWM signals; and the output end of the current driving circuit is connected with the control end of the power switching device. A voltage change rate dv/dt signal is detected through the differential circuit, when the dv/dt signal is larger than the reference voltage, the current driving circuit is controlled, instantaneous current is provided, gate driving current is reduced, and the voltage overshoot is maintained to be unchanged basically. The driving circuit can be accurately controlled to output voltage and current, the turn-off speed is quickened, and the turn-off loss is reduced.

The invention discloses a drive circuit of a silicon carbide semiconductor field effect transistor. The drive circuit comprises a PWM control circuit, a drive signal amplification circuit, a turn-offcircuit, a gate shunt circuit and a current change rate control circuit, wherein the gate shunt circuit is switched on when the turn-off circuit works to perform shunt of the gate current of a SiC MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and accelerate the switch-off of the SiC MOSFET; the SiC MOSFET is switched off when the drain-source voltage of the SiC MOSFET is increased toa preset value; the current change rate control circuit is switched off when the drain-source voltage of the SiC MOSFET is increased to the preset value to reduce the leakage current change rate. Thegate shunt circuit is arranged to perform shunt of the gate output current in the SiC MOSFET switch-off process and speed up the decreasing speed of the gate-source voltage so as to improve the switch-off speed of the SiC MOSFET; and besides, in the switch-off process of the SiC MOSFET, the switch-off of the current change rate control circuit reduces the leakage current change rate so as to reduce the voltage peak when the SiC MOSFET is switched off, the two circuits cooperatively act to achieve the voltage reduction speed and the low-voltage peak of the high gate-source voltage and ensure the safety operation of the SiC MOSFET.

The invention provides an under-voltage protection circuit used for protecting a power supply of an electric appliance when an external input voltage is too low. The electric appliance comprises a filter network, a bridge rectifier unit, an active power factor correction boost module, and a power supply controller. The under-voltage protection circuit is characterized in that the circuit is connected between an output terminal of the bridge rectifier unit and an input terminal of the power supply controller; and when the output voltage of the under-voltage protection circuit is lower than the turn-off threshold voltage of the power supply controller, the power supply controller stops working, and the power supply of the electric appliance is cut off. The technical proposal has lower cost and simple and reliable circuit, solves the problem that the hysteresis amount of the power supply controller in the prior art can not meet the demands in practical application, and improves the turn-off speed of the power supply.

A current enhanced type lateral insulated gate bipolar transistor improves current density and the turn-off speed on the premise that a latching ability is maintained to be unchanged. The semiconductor is provided with buried oxide disposed on a P-type substrate and an N-drift region disposed on the buried oxide, a P-body region and an N-buffer region are disposed on the N-drift region, a P-type collecting electrode region is disposed in the N-buffer region, an anode metal is connected to the P-type collecting electrode region, a field oxide layer is disposed on the N-drift region, a P-well region is disposed in the P-body region, a P-type emitting electrode region and an emitting electrode region are disposed in the P-well region, the inner-side boundaries of the four regions, i.e., the P-body region, the P-well region, the P-type emitting electrode region and the emitting electrode region are synchronously recessed inwardly to form a square groove, the emitting electrode region surrounding the groove is successively defined as a first P-type emitting electrode region, second, third and fourth N-type emitting electrode regions and a fifth P-type emitting electrode region, the N-drift region protrudes outwardly and fills the square groove, a surface of the P-body region is provided with a gate oxide layer, a surface of the gate oxide layer is provided with a polysilicon layer, and a gate metal is connected to the polysilicon layer.

The invention discloses an insulated gate bipolar transistor (IGBT) driving push-pull circuit, which mainly comprises an NPN triode (Q1), a PNP triode (Q2), a charging resistor (R5) and a discharging resistor (R6), wherein one end of the charging resistor (R5) is connected to an anode of an input power supply (VDC1), and the other end of the charging resistor (R5) is connected to a collector (c1) of the NPN triode (Q1); an emitter (e1) of the NPN triode (Q1) and an emitter (e2) of the PNP triode (Q2) are connected to form a point and connected with a gate (G) of an IGBT; the emitter (e2) of the PNP triode (Q2) is connected with one end of the discharging resistor (R6); and the other end of the discharging resistor (R6) is connected with the ground of a power supply (VDC2). By adoption of a push-pull circuit structure, in the turn-on moment of the IGBT, the NPN triode works in a saturation area, charging current is improved, and the loss of the NPN triode is reduced; and in the turn-off moment of the IGBT, the PNP triode works in the saturation area, discharging current is improved, and the loss of the PNP triode is reduced.

The invention belongs to the technical field of power semiconductors and particularly relates to a high-speed and low-loss multi-trench gate high-voltage power device. Compared with a traditional structure, the structure of the high-speed and low-loss multi-trench gate high-voltage power device has the advantage that a plurality of trench gate structures are introduced into an emitter terminal anda collector terminal. Channels in side walls of trench gates at the collector terminal are turned off and a connection path of an N+ collector region and an N-type buffer layer is blocked during forward conduction, so that the voltage foldback effect can be eliminated. A trench gate structure at the emitter terminal can increase the channel density to reduce the resistance of a channel region, and a barrier trench gate and a carrier storage layer can effectively improve the carrier concentration of a drift region, so that the novel device can obtain lower forward conduction voltage drop. In the turn-off process, the channels in the side walls of the trench gates at the collector terminal are opened along with voltage rise of a collector, so that the N+ collector region communicates with the N-type buffer layer to form a rapid electron extraction path and turn-off of the device is accelerated to reduce the turn-off loss. Therefore, the high-speed and low-loss multi-trench gate high-voltage power device has lower forward conduction voltage drop and smaller turn-off loss and does not have the voltage foldback effect.

The invention discloses a power device soft switching-off circuit comprising a load electronic component Load, an input voltage and a lead inductor arranged in the same series circuit of a power device. The power device is connected to power device withstand voltage, driving voltage and the gate capacitor of the power device. A driving circuit is disposed on a circuit where the power device is connected with the driving voltage in series. The power device soft switching-off circuit processes a switching-off process in segments. The switching-off speed is increased at the phase t1-t2 and the phase t2-t3, and is slowed down at the phase t3-t4. The switching-off speed is increased at the phase t2-t3 in order to reduce the loss of the switching-off phase, and is slowed down at the phase t3-t4in order to reduce the induced voltage caused by switching-off. The total switching-off time and total switching-off loss are balanced in order to reduce the voltage applied to the power device and reduces the losses and heat generation of the power device.

According to the gate voltage bootstrap sampling switch circuit adopting the mirror image structure, the bootstrap capacitance is increased to two times of that of a traditional circuit by adopting the mirror image structure, and the linearity of a sampling switch is improved; channel charge injection is inhibited by adopting a technology of absorbing channel charges generated by related MOS tubesby a clock-controlled virtual MOS tube; and a structure that the output end of a clock-controlled inverter drives an NMOS tube M10 and an NMOS tube M12 is adopted. The parasitic capacitance of the grid node of the sampling switch tube M11 is reduced; circuit charge sharing is suppressed, and, at the sampling start phase, the NMOS tube M10 and the NMOS tube M12 are respectively conducted with thePMOS tube MOS tube M5 and the PMOS tube M13 at the same time, and the conducted speed of the sampling switch is speeded up; and at the moment from sampling to holding conversion, a circuit composed ofthe PMOS tube M8 and the NMOS tube M9 and a circuit composed of the PMOS tube M16 and the NMOS tube M17 are kept on for a period of time at the same time, and the turn-off speed of the sampling switch is increased. According to the circuit, the linearity and the switching speed of the gate voltage bootstrap sampling switch circuit are effectively improved, so that the overall performance of the gate voltage bootstrap sampling switch circuit is effectively improved.