47results about How to "Small output resistance" patented technology

The invention discloses a charge pump structure for a phase-locked loop circuit, which is used to convert the phase difference signal output by a frequency discriminator or phase detector to the voltage signal so that to control the output signal frequency of a VCO(voltage controlled oscillator). The invention is characterized in that the charge bump structure includes two identical buffer units which is used to convert the single end signal to differential signal and can generate two complementary differential signals on the Up signal and Down signal, and a charge and loop filter unit which are formed by two identical charge pump circuits connected in series and are used to convert the complementary differential signal to the voltage signal. The charge pump structure of the invention eliminates the influence of parasitic capacitance, reduces the mismatch degree of the transistor during manufacture and keeps the relative matching of the transistor.

A twelve-lead electrocardiosignal synchronous acquisition module belongs to the technical field of medical devices and solves the problems that the existing twelve-lead electrocardiogram adopts wired measurement, so the detection is inconvenient and the measuring equipment is high in cost. The twelve-lead electrocardiosignal synchronous acquisition module comprises a body surface electrode, an electrocardiosignal input circuit, a differential amplification circuit, a filter circuit, a lead selection circuit, a signal amplification circuit, a analog-digital conversion circuit, a single chip computer and a level switching circuit all connected in sequence. When in use, the twelve-lead electrocardiosignal synchronous acquisition module disclosed by the invention is connected with an embedded WIFI module, and then connected with a computer in a wireless manner, so a low-cost domestic twelve-lead electrocardiogram wireless measuring system is established, domestic wireless measurement of the electrocardiogram is realized, the electrocardiogram detection is convenient, and the detecting equipment is low in cost.

Disclosed is a room temperature ammonia (NH3) sensor based on DPA-Ph-DBPzDCN and gold interdigital electrodes and preparation method therefor, belonging to the technical field of gas sensors. The roomtemperature NH3 sensor is composed of an Al2O3 ceramic plate, gold interdigital electrode bases, and a DPA-Ph-DBPzDCN sensitive material thin film from bottom to top. The preparation method comprisesthe following steps: preparing a DPA-Ph-DBPzDCN sensitive material through Suzuki coupling reaction; separately preparing nickel and gold on the Al2O3 ceramic substrate to prepare interdigital electrodes by sputtering; and preparing the DPA-Ph-DBPzDCN sensitive material on the interdigital electrodes by using a spin coating method. According to the room temperature NH3 sensor based on DPA-Ph-DBPzDCN and gold interdigital electrodes and preparation method therefor, a novel organic material DPA-Ph-DBPzDCN is used as a sensitive material, so that the working temperature of the sensor is effectively reduced, and ammonia gas can be detected at room temperature; and good selectivity and stability are achieved besides a rapid response speed for ammonia gas at room temperature.

The invention relates to a polymer solar cell. The polymer solar cell sequentially comprises a cathode layer, a cathode interface layer, a photosensitive layer, an anode interface layer and an anode layer, wherein the cathode interface layer is an inorganic semiconductor nanocrystalline-conjugated polymer composite material layer. The cathode interface layer is specifically a ZnO-PFEP (phosphate ester polyfluorene) composite material layer. According to the polymer solar cell, the ZnO-PFEP composite cathode interface layer is arranged between the cathode layer and the photosensitive layer, and the mass ratio of ZnO to PFEP in the interface layer is controlled, so that the electrical conductivity of the cathode interface layer can be effectively increased, the bulk resistance of the cathode interface layer is reduced, the electron output resistance is decreased, furthermore, the short-circuit current, open-circuit voltage, fill factor and energy conversion efficiency of the cell are improved, and the electron transportation and collection are benefited.

The invention discloses a transimpedance amplifier applied to a high-speed optical receiver and a design method. The transimpedance amplifier comprises a three-level high gain amplifier A and a feedback resistor Rf. The three-level high gain amplifier A comprises a first-level amplifier A1, a second-level amplifier A2 and a third-level amplifier A3. The output end of the first-level amplifier A1 is connected with the input end of the second-level amplifier A2. The output end of the second-level amplifier A2 is connected with the input end of the third-level amplifier A3. Two ends of the feedback resistor Rf are connected with the input end of the first-level amplifier A1 and the output end of the third-level amplifier A3. According to the transimpedance amplifier, a structure of reducing bandwidth and then increasing the bandwidth is employed in the amplifier of the TIA (Transimpedance Amplifier), so under the condition of ensuring the bandwidth required by a system transmission rate, the transimpedance gain of the TIA is improved, and the equivalent input noise of the TIA is reduced.

The present invention discloses an electrode falling detection circuit. The electrode falling detection circuit comprises an impedance detection unit and a processor; the impedance detection unit is connected with electrodes and used for receiving impedance detection signals, also uses the impedance detection signals to detect electrode-loaded impedance and generates impedance signals; and the processor is connected with the impedance detection unit and used for providing the impedance detection signals for the impedance detection unit, calculates an impedance value according to the impedancesignals generated by the impedance detection unit and judges whether the electrodes fall off from a human body or not according to the impedance value. By detecting the electrode-loaded impedance value, if the impedance value is larger than a threshold value, the electrodes are considered to fall off from the human body and detection of falling-off of the electrodes from the human body is achieved.

The invention discloses a transient enhancement circuit applied to a low-power-consumption fully-integrated low dropout regulator. The transient enhancement circuit comprises an LDO control main loop, an undershoot suppression circuit, an undershoot recovery circuit, an overshoot suppression circuit and an overshoot recovery circuit. According to the circuit, overshoot suppression and transient enhancement of output voltage are realized by detecting transient voltage change of an output node of a power MOS (Metal Oxide Semiconductor) tube: when light load and heavy load of load current are instantaneously switched, a corresponding suppression circuit and a corresponding recovery circuit work, and corresponding pull-up current and pull-down current are provided, so that overshoot of the output voltage is suppressed, and recovery is accelerated. Moreover, when the output voltage is stable, all pull-up MOS tubes and pull-down MOS tubes of the transient enhancement circuit are turned off, and excessive static power consumption is not increased. A simulation result shows that the response capability of the low-power-consumption fully-integrated low-dropout linear regulator to transient change of load current can be remarkably improved.

The invention provides a current measurement method, power supply equipment and a power supply chip. The method is applied to a power supply chip. The power supply chip includes an output module and acontrol module, wherein the output module comprises a first switching element and a second switching element; the output module supplies power to a load through an inductance element and a capacitance element which are externally coupled to the power supply chip. The method comprises the steps of providing a switching signal for the first switching element, and acquiring a voltage signal of the inductance element, wherein the voltage signal comprises an input voltage signal and an output voltage signal of the inductance element; obtaining a current ripple characteristic parameter of the inductance element, and determining an inductance value of the inductance element based on the current ripple characteristic parameter; and determining a current signal of the inductance element based on the voltage signal, the inductance value, and the switching signal. Through the embodiment of the invention, the current measurement precision can be improved, and the power supply efficiency is further improved.

A method for preparing displacement transducer of radio-frequency single electronic transistor type includes preparing beams being fixed at two ends and single electronic transistor on SOI substrate, utilizing nanoscale beams being fixed at two ends as sensitive elements and utilizing radio-frequency single electronic transistor as sensing element to form fast supersensitive displacement transducer.

The invention discloses a structure and a preparation method of an MOSFET device based on a diamond substrate, and belongs to the technical field of microelectronics. The structure comprises a diamond substrate, hydrogen terminal layers arranged at the upper end and the lower end of the diamond substrate, a source electrode and a drain electrode arranged on the two sides of the diamond substrate respectively, gate dielectric layers arranged on the surfaces of the hydrogen terminal layers and gate electrodes arranged on the surfaces of the gate dielectric layers. According to the double-gate diamond device formed by the method, the maximum saturation current and transconductance of the diamond device can be improved under the condition of keeping the threshold voltage basically unchanged, the switching ratio of the device is improved by nearly three orders of magnitudes, the output resistance of the device is reduced, the cut-off frequency of the diamond device is greatly improved, and the characteristics of simple manufacturing process and good repeatability are achieved.

The invention belongs to the technical field of integrated circuits, and relates to a buffer circuit used for an LDO. Compared with a traditional LDO circuit, in the buffer circuit used for the LDO, the buffer circuit is added; the buffer circuit can improve the driving capacity of an error amplifier, so that the transient response of the LDO is drastically improved; besides, since the buffer circuit is composed of a source follower, the source follower has an extremely low output resistance, and therefore, a pole P3 generated by an output end of the error amplifier can be pushed to a higher frequency, so that the stability of the circuit is not influenced by the pole P3; more importantly, in the buffer circuit, through the design of the circuit structure, the quiescent current of the buffer is reduced, which has very significant importance in the reduction of the overall power consumption of the LDO circuit.

The invention discloses an input and output circuit for a solid-state relay and the solid-state relay. The relay has the advantages of high load capacity, high reliability, high insulation resistance,high overload capacity, high reliability and high salt spray resistance. The control speed is high, and the driving energy requirement is low; the overall dimension is designed to be 21.8 mm*12.8 mm*10 mm. The solid-state relay provided by the invention is compact in structure, small in size and light in weight, and the weight of the solid-state relay provided by the invention is less than 8g; under the limitation of volume and weight conditions, small output resistance, low power consumption and high output power are ensured.

The invention discloses a voltage buffer applied to an SAR (Successive Approximation Register) ADC (Analog to Digital Converter). The voltage buffer comprises an error amplifier, a voltage buffer output circuit and a level detection circuit, wherein the voltage buffer is used for providing a reference voltage to a capacitive DAC of the SAR ADC, has high capability of driving a large-capacitance load, and can meet the requirement that the reference voltage needs to quickly restore due to a change of the capacitance load. The voltage buffer also has rapid starting capability; required reference voltage can be quickly built by the voltage buffer when the circuit is electrified to start, and the time that the SAR ADC enters a normal working state from a dormant state is shortened, so that the response speed of the SAR ADC is improved. Compared with a traditional voltage buffer applied to the SAR ADC, the voltage buffer disclosed by the invention has the advantages that the capability of driving the capacitance load is higher, and the power consumption is lower.

The invention discloses a planar room-temperature NH3 sensor based on a TPA-DCPP (7,10-bis(diphenyl amino) phenyl-2,3-dicyanopyrazino phenanthrene) organic sensitive film, and a preparation method thereof, and belongs to the technical field of gas sensors. The sensor consist of an Al2O3 ceramic plate, a gold interdigital electrode and a TPA-DCPP organic sensitive material film from bottom to top in sequence. The preparation method for the planar room-temperature NH3 sensor comprises the following steps that: firstly, through Suzuki coupled reaction, preparing a TPA-DCPP organic sensitive material; then, through a sputtering method, independently preparing nickel and gold to the Al2O3 ceramic substrate to prepare the interdigital electrode; and then, utilizing a spin-coating method to prepare the TPA-DCPP organic sensitive material on the interdigital electrode. By use of the sensor and the preparation method, the working temperature of the sensor is effectively lowered, the NH3 can bedetected under a room temperature condition, and the ppb(part per billion)-magnitude detection of the NH3 can be realized under high humidity (98%RH (Relative Humidity)). In addition to a high response speed for the NH3 at the room temperature, the sensor disclosed by the invention also has good selectivity and stability.

The invention discloses an error amplifier for a large-current DCDC power supply module. The error amplifier comprises a soft start circuit and an error amplifier main circuit. The soft start circuit is used for stabilizing rising voltage during starting; the error amplifier main circuit is used for comparing the feedback voltage VFB with the reference voltage VREF, and the error amplifier main circuit and the compensation capacitor form a secondary dominant pole far away from the original point. The error amplifier is applied to a large-current DCDC power module, the pole position of the output end of the error amplifier is far away from the original point position and serves as a secondary dominant pole of a power module system by increasing the transconductance of the error amplifier and reducing the output resistance technically, and the system stability is guaranteed.

The invention provides an ultra-low noise signal amplification circuit for a capacitive ocean inert material electrode. The ultra-low noise signal amplification circuit comprises a chopping modulation circuit which is used for modulating an ultra-low frequency broadband weak signal into a high-frequency signal to avoid flicker noise of a subsequent signal processing circuit; a potential impedance matching circuit which is used for providing reference potential of a chopping modulation control signal and matching impedance of an electrode; a high input impedance differential alternating current amplification circuit which is used for performing low-noise differential amplification processing on a signal and converting a differential signal into a single-ended signal; a chopping demodulation circuit which is used for demodulating the high-frequency signal into a low-frequency signal and recovering an amplified low-frequency broadband signal; a low-pass filter circuit which is used for filtering high-frequency noise generated by modulation and demodulation; and a high input impedance direct current amplification circuit which is used for impedance matching of circuit output. The signal amplification circuit provided by the invention is an ultra-low noise signal amplification circuit for impedance matching of a capacitive electrode, and is suitable for signal detection of an easily polarized capacitive ocean inert material electrode.

The embodiment of the invention discloses a CAN bus communication system. The CAN bus communication system comprises a constant current source and a group of differential transmission lines, wherein the differential transmission lines comprise a CANH line and a CANL line. The positive electrode end of the constant current source is electrically connected with the CANL line, and the negative electrode end of the constant current source is electrically connected with the CANH line. According to the embodiment of the invention, the external constant current source can provide a reverse current for the CAN bus, which is equivalent to reducing the output resistance of the bus when the hidden level is transmitted, so that the time for the bus to jump to the hidden level when the bus has relatively large parasitic capacitance can be obviously reduced, and further the error rate is reduced and the transmission accuracy is improved. Meanwhile, the CAN bus communication system is provided with a terminal resistor, the positive electrode end of the constant current source is electrically connected with the CANL line, and the negative electrode end of the constant current source is electrically connected with the CANH line, so that the steady-state voltage of the CAN bus communication system is reduced to a negative value, the difference between a hidden level threshold value and the steady-state voltage is increased, the error rate is further reduced, and the accuracy of bus signal transmission is improved.

The invention discloses a short circuit detection circuit, a short circuit protection circuit and a switching power supply circuit. The short circuit detection circuit comprises a sampling circuit which is connected with a communication line, avoltage follower, a controller and avoltage stabilizing circuit, wherein the sampling circuit is used for collecting the working voltage of the communication line; the input end of the voltage follower is connected with the sampling circuit, and the output end of the voltage follower is connected with the input end of the controller; the controller is used for judging whether the communication line is short-circuited or not according to the voltage output by the voltage follower; one end of the voltage stabilizing circuit is connected with the output end of the voltage follower; and the voltage stabilizing circuit has a charging state and a discharging state. According to the arrangement, when the communication line works normally and the voltage fluctuates, the voltage stabilizing circuit can enable the voltage obtained by the input end of the controller to be maintained at a high value, so that the condition of triggering short circuit protection is met, and the reliability of the short circuit detection circuit is improved.

The invention discloses a low-resistance transmission circuit based on a CVP probe active integration method. The low-resistance transmission circuit consists of a CVP probe unit, an integration unit and an impedance conversion unit, wherein high-voltage pulse square waves are input into an input end of the CVP probe unit; high resistance is set between integration signal output circuits of an RC integration circuit; low resistance is set between output circuits of the impedance conversion unit; and the output circuits of the impedance conversion unit are directly connected to a signal transmission line. Through adoption of the low-resistance transmission circuit, a low-resistance transmission technology based on the CVP probe active integration method is realized under the situation that technical problems in a general integration method are solved completely. An active integrator is directly connected with a CVP probe output end, so that the influence of a long cable on a differential signal high-frequency component is eliminated, and the problem that general test measures such as integration signal transmission (long cables or optical fibers), impedance matching, signal shutting or overlapping cannot be taken on the aspect of testing technology is well solved.