12 results about "Feedback capacitance" patented technology

The reduction of feedback capacitance in active semiconductor devices, such as the reduction in collector to base capacitance in transistors, is described. In one example, a transistor includes a substrate, an active region of the transistor in the substrate, a dielectric layer over a top surface of the substrate, and an interconnect region. The active region includes a base contact over the active region. The interconnect region includes a conductive interconnect that extends over the dielectric layer and is electrically coupled with the base contact. The interconnect region also includes a semiconductor junction region extending under the conductive interconnect in an area of the substrate outside of the active region. The addition of the semiconductor junction region under the conductive interconnect reduces the total collector to base capacitance in the transistor.

Embodiments of the present application relate to an IGBT device and a preparation method of the IGBT device, wherein the IGBT device comprises a cell region, a plurality of trench gates are arranged in the cell region, the plurality of trench gates at least comprise a first trench gate and a second trench gate, a cross-sectional area of the first trench gate and a cross-sectional area of the second trench gate are different, a depth of the first trench gate and a depth of the second trench gate are the same; the first trench gate and the second trench gate are connected to a gate potential; thus, it is beneficial to adjust the feedback capacitance of the device, improve the switching characteristics of the device, avoid the current oscillation problem, and improve the stability of the device working.

To improve the measurement accuracy of feedback capacitance of a semiconductor device. Between a gate terminal of a semiconductor device subject to measurement and an Lc terminal of an LCR meter, a first wiring that is passed through a core of a transformer once and connected between a gate terminal and a source terminal and a second wiring wound N times around a core of the transformer, and one end is connected to the Lc terminal and the other end is grounded are provided. when ω represents an angular frequency of the AC signal applied to the drain terminal of the semiconductor device, LS_6A represents inductance of the first wiring, LS_6B represents inductance of the second wiring, and CGS represents gate-source parasitic capacitance of the semiconductor device, a relationship of ωLS_6A<1 / (ωCGS), and ωLS_6B / N2<1 / (ωCGS) are satisfied.

The invention discloses a transimpedance amplification circuit and a photoelectric signal detection system. The transimpedance amplification circuit is applied to a photodiode and comprises a bootstrap input stage and a capacitance feedback transimpedance amplification stage. The bootstrap input stage comprises a bootstrap amplifier and a first coupling capacitor; the in-phase input end of the bootstrap amplifier is connected with the cathode of the photodiode, and the output end is connected with the anode of the photodiode through the first coupling capacitor to form bootstrap feedback. The capacitance feedback transimpedance amplification stage at least comprises a first-stage integral amplification circuit, and the input end of the first-stage integral amplification circuit is connected with the cathode of the photodiode. According to the circuit, approximately equal-amplitude in-phase voltage changes are generated at the two ends of a parasitic capacitor of a photodiode through bootstrap feedback, the shunt effect of the parasitic capacitor is effectively inhibited, and the noise gain of a system is reduced; and meanwhile, the integral amplification circuit directly performs high-bandwidth conversion on the current signal, so that the high-speed processing capability is guaranteed. According to the circuit, noise performance is remarkably improved while high bandwidth and high sampling rate are maintained, and collaborative optimization of high bandwidth, high sampling rate and low noise is achieved.

The invention discloses a high-gain and phase-stable trans-impedance amplification circuit of an MEMS (Micro Electro Mechanical System) capacitive transducer, which is used for converting a current signal of an MEMS resonator into a stable voltage signal. The trans-impedance amplification circuit of the MEMS capacitive transducer comprises a first-stage integrator and a second-stage phase shifter, wherein the first-stage integrator is used for receiving a differential induction current signal of the MEMS resonator and performing integral amplification, and a feedback capacitor of the first-stage integrator is directly composed of an output capacitor of the MEMS resonator; mechanical homologous capacitance feedback is realized; and the second-stage phase shifter is connected to the output end of the first-stage integrator and is used for carrying out phase compensation on the integrated signal so as to meet the phase condition of loop oscillation. According to the amplification circuit provided by the invention, by adopting a mechanical homologous capacitance feedback technology and a two-stage cascade structure of the integrator and the phase shifter, the zero temperature drift characteristic of transimpedance gain and the accurate and stable control of a loop phase are realized.

The application discloses a low-offset comparator for inhibiting sampling signal attenuation, relates to the technical field of analog and mixed signal integrated circuit design, and is used for solving the problems of sampling signal amplitude attenuation caused by input parasitic capacitance and sampling capacitance voltage division of a pre-amplification stage of a comparator in the prior art and deterioration of ADC linearity and dynamic range caused by the problems. The low-offset comparator comprises a sample-and-hold enhancement circuit and a subsequent processing circuit, the sample-and-hold enhancement circuit is connected between a sample-and-hold circuit and the subsequent processing circuit, the subsequent processing circuit comprises a pre-amplification stage with an input transistor pair, the sample-and-hold enhancement circuit comprises an input capacitance neutralization network, the input capacitance neutralization network is connected between a differential input end and a differential output end of the pre-amplification stage, is used for generating a feedback capacitance opposite to inherent gate-drain capacitance effect of the input transistor pair, and thus effectively reduces the input capacitance of the pre-amplification stage at a sampling node of the sample-and-hold circuit.

A gate fabrication method of an UMOSFET and a trench gate structure formed thereof are provided, comprising providing a transistor structure and a lithography process is employed to define a trench region. A gate oxide layer is deposited along the trench and two polysilicon sidewalls having a spacing there in between are formed afterwards. A wet etching is used to remove the gate oxide layer underneath the polysilicon sidewalls such that a vacancy is formed at the trench bottom. By oxidizing the polysilicon sidewalls, a thick oxide layer is formed, enfolding periphery of the polysilicon sidewalls and filling the vacancy. The spacing can be alternatively retained between the polysilicon sidewalls covered with the thick oxide layer, such that the trench can be alternatively filled. The present invention is effective in increasing oxide thickness of the gate bottom, reducing the trench corner curvature as well as the feedback capacitance.

The utility model discloses a pressure sensor circuit with a built-in MCU, and relates to the field of pressure sensors, and the pressure sensor circuit with the built-in MCU comprises a ceramic capacitor which is used for changing the capacitance when the pressure changes and feeding back a capacitance signal to a main chip; the main chip is used for outputting 0-5V voltage based on the magnitude of the input capacitance signal; the ceramic capacitor is connected with the main chip; compared with the prior art, the utility model has the beneficial effects that the zero point and the second-order temperature drift (the highest third-order nonlinearity) of the sensitivity of the pressure sensor are calibrated through the main chip, the calibration precision can be within 0.1%, and the calibration coefficient is stored in a group of EEPROM (Electrically Erasable Programmable Read-Only Memory) which can be programmed for multiple times; the problems that in the new energy automobile thermal management system technology, the precision of a pressure sensor is not high, and output data drifts in the high and low temperature environment are solved.

The invention relates to a power semiconductor device with low electromagnetic interference. The second conductive type well region comprises an active region, a central region distributed in the semiconductor substrate and a plurality of cells distributed in parallel, each cell comprises a cell groove, the cell groove penetrates through the second conductive type well region in the active region, and each cell groove is filled with a groove gate; in the active region, a groove partition unit is arranged on one side of at least one cell, and the groove partition unit is in contact with one side wall of a cell groove in the cell, so that the cell groove is isolated from the second conductive type well region on the corresponding side through the groove partition unit; and the trench gates in all the cells are electrically connected with the front surface first electrode metal above the front surface of the semiconductor substrate. According to the invention, the input capacitance of the power semiconductor device can be reduced under the condition that the feedback capacitance is maintained, so that the electromagnetic interference and the voltage stress to the load when the power semiconductor device is turned on are reduced.

The utility model discloses a power supply output voltage overshoot suppression control circuit, which comprises an operational amplifier U15 and a plurality of differential sampling resistors, the plurality of differential sampling resistors are a resistor R52, a resistor R56, a resistor R58 and a resistor R64, a pin 3 and a pin 4 of the operational amplifier U15 are connected with output voltage Vo + and Vo-through the resistor R56 and the resistor R58, and the operational amplifier U15 is connected with the output voltage Vo + and the output voltage Vo-through the resistor R56 and the resistor R58. A pin 5 of the operational amplifier U15 is connected with a power supply voltage Vcs5V and a power supply end capacitor C81, a pin 1 of the operational amplifier U15 outputs a voltage signal Vos through a first-order low-pass RC filter, an operational amplifier feedback capacitor C71 is connected between a pin 4 and the pin 1 of the operational amplifier U15, and two ends of the operational amplifier feedback capacitor C71 are connected in parallel with a differential sampling resistor R64. According to the utility model, the large drop of the output voltage of the module after wave sealing is greatly avoided, the under-voltage protection is not easy to trigger, and the drop of the output voltage to zero under the full-load working condition caused by the slow increase of the duty ratio after zero clearing is avoided.

A piezoelectric measuring device includes a sensor element that generates a measurement signal for a pressure and a data acquisition device to evaluate the measurement signal. The sensor element includes an operational amplifier with an inverting input and an output, a feedback capacitance in parallel with the inverting input and the output, and a reset switching element in parallel with the inverting input and the output. The operational amplifier provides an electrical supply voltage and the data acquisition device includes a measurement cycle circuit configured to activate the electrical supply voltage before a measurement cycle and deactivate after the measurement cycle. The sensor element includes a power-on reset logic to detect the electrical supply voltage accordingly close or reopen the reset switching element.

The application relates to a method for realizing double-channel laser cutting height adjustment control based on a capacitive sensor, which comprises the following steps: dynamically creating a channel space; selecting a channel height adjustment mode and providing a channel mode selection interface to an upper computer; in a step distance planning mode, independently planning in the respective channel space; in an automatic following mode, independently feeding back capacitive data according to the current position of a cutting head obtained through capacitive feedback; dynamically adjusting a target position; and performing height adjustment output control through the difference between the current position of the cutting head and the height adjustment target position. The application also relates to a device for realizing double-channel laser cutting height adjustment control based on a capacitive sensor, a processor and a storage medium. The method, the device, the processor and the computer readable storage medium for realizing double-channel laser cutting height adjustment control based on a capacitive sensor solve the problems of single machining scene and low cutting efficiency caused by single-channel cutting.