61results about How to "Extended input voltage range" patented technology

A differential circuit and an amplifier circuit for reducing an amplitude difference deviation, performing a full-range drive, and consuming less power are disclosed. The circuit includes a first pair of p-type transistors and a second pair of n-type transistors. A first current source and a first switch are connected in parallel between the sources of the first pair of transistors, which are tied together, and a power supply VDD. A second current source and a second switch are connected in parallel between the sources of the second pair of transistors, which are tied together, and a power supply VSS. The circuit further includes connection changeover means that performs the changeover of first and second pairs between a differential pair that receives differential input voltages and a current mirror pair that is the load of the differential pair. When one of the two pairs is the differential pair, the other is the current mirror pair. In a differential amplifier circuit, there is provided an added transistor connected in parallel to a transistor, which is one transistor of a differential pair transistors, whose control terminal is a non-inverting input terminal. The added transistor has a control terminal for receiving a control voltage which is set so that, when an input voltage applied to the non-inverting input terminal is in a range in which the transistor whose control terminal is the non-inverting input terminal is turned off, the added transistor is turned on.

A fingerprint identification system and a test device including the fingerprint identification system, the fingerprint identification system includes: a fingerprint sensor for detecting a fingerprint pattern and converting the fingerprint pattern into a discrete analog signal about fingerprint information; a drive circuit The unit is used to perform data processing on the discrete analog signal detected by the fingerprint sensor, and the drive circuit unit includes: a controller used to drive the fingerprint sensor; a sampling and holding circuit used to collect and maintain the instantaneous voltage of the discrete analog signal , forming a continuous analog signal; an analog-to-digital conversion unit, used to convert the continuous analog signal into a digital signal; a full-scale voltage adjustment unit, used to adjust the full-scale voltage of the analog-to-digital conversion unit, and the full-scale voltage is the analog-to-digital conversion unit Maximum input voltage for analog-to-digital conversion. The fingerprint identification system has excellent performance, high yield rate, and overcomes the problem of short service life caused by aging.

A switching voltage regulator has a first switch, a second switch, and an inductor, which are coupled together to a switch node. A switch control system applies a drive signal for controlling the first and the second switches. A duty cycle detecting circuit detects a duty cycle of the drive signal. When the duty cycle is larger than a predetermined threshold, the duty cycle detecting circuit generates an over-threshold signal. When the duty cycle is smaller than the predetermined threshold, the duty cycle detecting circuit generates an under-threshold signal. In response to the over-threshold signal and the under-threshold signal, an oscillating signal adjusting circuit generates an adjusting current. An oscillating signal generating circuit generates and applies an oscillating signal to the switch control system. The oscillating signal has a period adjusted by the adjusting current.

A differential circuit and an amplifier circuit for reducing an amplitude difference deviation, performing a full-range drive, and consuming less power are disclosed. The circuit includes a first pair of p-type transistors and a second pair of n-type transistors. A first current source and a first switch are connected in parallel between the sources of the first pair of transistors, which are tied together, and a power supply VDD. A second current source and a second switch are connected in parallel between the sources of the second pair of transistors, which are tied together, and a power supply VSS. The circuit further includes connection changeover means that performs the changeover of first and second pairs between a differential pair that receives differential input voltages and a current mirror pair that is the load of the differential pair. When one of the two pairs is the differential pair, the other is the current mirror pair. In a differential amplifier circuit, there is provided an added transistor connected in parallel to a transistor, which is one transistor of a differential pair transistors, whose control terminal is a non-inverting input terminal. The added transistor has a control terminal for receiving a control voltage which is set so that, when an input voltage applied to the non-inverting input terminal is in a range in which the transistor whose control terminal is the non-inverting input terminal is turned off, the added transistor is turned on.

The invention relates to a method for operating a switched mode power supply as an isolating transformer. According to said method, magnetic energy is stored in the core of a transformer during a storage stage via a primary coil that is connected to an intermediate circuit current and the stored magnetic energy is delivered to a load in a subsequent discharge phase, for the most part by means of a secondary coil, a small part of said magnetic energy being discharged on the primary side. The energy that is discharged on the primary side charges a capacitor in such a way that the capacitor current is always held above the secondary current multiplied by the transmittance ratio of the transformer.

In order to widen an operational input voltage range of a power conversion apparatus and obtain a maximum efficiency value comparable to that in a case where the operational input voltage range is not widened by changing software but not hardware, provided is a power conversion apparatus, in which a control section (5) controls a current input to an inverter circuit (14) to cause a DC output voltage from an AC / DC converter section (10) which is a voltage across a smoothing capacitor (22) to follow a target voltage and to cause an input power factor from an AC power supply (1) to approach one, to thereby maintain a DC voltage from a single-phase inverter (14a), and adjusts the target voltage for the DC output voltage from the AC / DC converter section (10) in accordance with a voltage of the AC power supply (1).

A switching voltage regulator has a first switch, a second switch, and an inductor, which are coupled together to a switch node. A switch control system applies a drive signal for controlling the first and the second switches. A duty cycle detecting circuit detects a duty cycle of the drive signal. When the duty cycle is larger than a predetermined threshold, the duty cycle detecting circuit generates an over-threshold signal. When the duty cycle is smaller than the predetermined threshold, the duty cycle detecting circuit generates an under-threshold signal. In response to the over-threshold signal and the under-threshold signal, an oscillating signal adjusting circuit generates an adjusting current. An oscillating signal generating circuit generates and applies an oscillating signal to the switch control system. The oscillating signal has a period adjusted by the adjusting current.

The invention relates to a switching power supply, and aims at solving a problem of damage to a power supply IC caused by over-high power grid input voltage of the existing non-isolated switching power supply in use. The non-isolated switching power supply circuit for super wide voltage input, provided by the invention, comprises a rectifier and filter circuit, a MOS tube voltage division circuit, a buck step-down circuit and a voltage stabilization output circuit. The non-isolated switching power supply circuit for super wide voltage input has the characteristics that an alternating current input voltage is processed by the rectifier and filter circuit to form a direct current bus voltage, the direct current bus voltage flows through the MOS tube voltage division circuit, the MOS tube voltage division circuit performs voltage division for a bus according to circuit design parameters and variation of application environment, the buck step-down circuit performs step-down treatment for the output of the MOS tube voltage division circuit, and the voltage stabilization output circuit performs secondary voltage stabilization filtering outputting for the output of the output of the buck step-down circuit. The non-isolated switching power supply circuit for super wide voltage input is suitable for a non-isolated switching power supply of which an input voltage is not steady.

An inverting amplifier which drives headphones via an output capacitor includes: an operational amplifier, an input resistor having a first terminal via which an audio signal to be amplified is received, and a second terminal connected to an inverting input terminal of the operational amplifier; and a feedback resistor having a first terminal connected to an inverting input terminal of the operational amplifier, and a second terminal connected to the output terminal. A reference voltage source generates a bias voltage Vb, and supplies it to the non-inverting input terminal. A discharging path includes a discharging resistor and a first switch arranged in series between an output terminal of the reference voltage source and an fixed voltage terminal. A second switch is arranged between the output terminal of the operational amplifier and a node on the discharging path where the electric potential is higher than it is at the discharging resistor.

This invention relates to a method for driving converts of an uninterrupted power supply (UPS), characterized in that the generating circuit of driving signal for power factor correction generates two driving signals (DRV1, DRV2) to drive the switch transistors (Q9, Q11) of the positive and negative power factor correction branch respectively, the holding and shifting circuit of driving pulse-width after the generating circuit of driving signal for power factor correction holds and shifts the pulse-width of the two driving signals, and drives the switch transistors (Q10, Q12) parallel to the aforesaid switch transistors in the positive and negative power factor correction branch respectively. Since a circuit for holding the pulse-width is introduced, the currents of the switch transistors of the two parallel boost converters are maintained substantially the same, thereby improving the reliability of the uninterrupted power supply system. As a result, this invention can be widely used in any application where a UPS is desired.

A tunable voltage-controlled pseudo-resistor structure, comprising: a symmetric PMOS transistor circuit and an auto-tuning circuit connected in series. Input of the auto-tuning circuit is connected to a central position Vf of the PMOS transistor circuit having its output Vg, with its purpose of keeping Vg−Vf at a constant value. The PMOS transistor circuit may produce body effect through various different bulk voltages. Through the auto-tuning circuit, Vg and Vf are kept constant to make current of transistor to produce compensation effect, such that regardless of Va>Vb or Va<Vb, a large resistance is maintained. Through utilizing the tunable voltage-controlled pseudo-resistor structure, constant resistance can be maintained under high input voltage, hereby reducing drifting of common-mode voltage, in achieving a superior resistance effect.

There is provided an apparatus and method for controlling a switch of a flyback converter for a solar generating system. The apparatus for controlling a switch of a flyback converter for a solar generating system includes: an MPPT controller generating a current command value for a maximum power point tracker of a solar cell module, based on input voltage, input current, and output voltage of the flyback converter; a current controller generating a current control signal for tracking the current command value; an output current command value generator generating the phase and magnitude command value of the output current, based on the phase of the output voltage and the current control signal; and a switch controller controlling the main switch of the flyback converter, based on the phase and magnitude command value of the output current, thereby simplifying a circuit while solving disadvantages of a discontinuous conduction mode and a boundary conduction mode.

The invention discloses a LDO (Low Dropout Regulator) with a wide input voltage range and a high power supply rejection ratio and belongs to the technical field of power electronics. The LDO comprisesan error amplifier, a power module, a pre-step-down module, a high voltage resistant module and a power supply rejection ratio enhancement module, wherein the pre-step-down circuit module is utilizedfor preprocessing an input voltage of the LDO to obtain a low power supply voltage used for supplying power to a low-voltage circuit part; power is supplied to the error amplifier and the high voltage resistant module so as to obtain a high power supply rejection ratio by utilizing the low power supply voltage, and the input voltage range of the LDO is widened by virtue of the high voltage resistant module; meanwhile, by utilizing the power supply rejection ratio enhancement module inside the LDO circuit, the power supply rejection ratio of the LDO at a high frequency end is further improved;finally the input voltage of the LDO is processed by utilizing the power module, a feedback voltage is obtained to control a positive input end of the error amplifier so as to obtain enough loop gainfor improving the output accuracy of the LDO, and the output voltage of the power module is a final output voltage of the LDO. The LDO disclosed by the invention is wide in input range, small in chipoccupied area and high in power supply rejection ratio.

The invention discloses a power-supply distribution unit capable of accessing various three-phase power supplies and single-phase power supplies, which comprises a separating power supply input component and input power-supply distribution component, wherein the power supply input component is used for transmitting the electric energy of an input power supply to the power-supply distribution unit capable of accessing various three-phase power supplies and single-phase power supplies; the input power-supply distribution component is separably connected to the power supply input component to distribute connection relations; and the mutual connection relation on one side of the input power-supply distribution component is in a delta type, Y type or a mutually-parallel type. The power-supply distribution unit is widely applicable to various commercial power specifications, and the corresponding power supply input component or / and input power-supply distribution component are replaced easily and quickly according to the corresponding commercial power supply specifications, so that the power-supply distribution unit is suitable for commercial power of different commercial power specifications. For manufacturers, the integral manufacturing cost and the complexity of assembly of the power-supply distribution unit capable of accessing the various three-phase power supplies and single-phase power supplies can be reduced effectively.

In an A / D conversion device, one level shift circuit shifts an input voltage to the low potential side by Vt1, and another level shift circuit shifts the input voltage to the high potential side by Vt2. A multiplexer selects either of the shifted voltages to an A / D converter. In a correction mode, a correction data holding circuit holds values of reference voltages that are also A / D converted after being passed through the one level shift circuit and values of reference voltages that are A / D converted by being passed through the other level shift circuit, as correction values. A correction control circuit corrects the A / D converted value using the correction values.

A DC / DC converter is provided for operation within a narrow voltage range during normal conditions, while allowing for a wider input voltage range for short periods of time. A first switch is coupled across first and second input terminals, and a capacitor is coupled in parallel with the first switch and across the input terminals. A second switch is coupled in series with the first input terminal and between the first switch and the capacitor. Operation of the switches is regulated in accordance with a bypass mode of operation when received input power is within a defined range, and a boost mode of operation when received input power is less than a threshold value, wherein the received input power is boosted to a bulk output power within the defined range. Boost operations may in various embodiments be provided via, for example, a critical conduction scheme or continuous conduction scheme.

The invention provides an interface circuit. The interface circuit comprises an input circuit. The input circuit comprises a clamping circuit unit, an input buffer unit and a first output driving unitcoupled to the clamping circuit unit and the input buffer unit. The clamping circuit unit is suitable for clamping a port voltage of the first output driving unit within a corresponding device voltage withstand range when the port power voltage of the interface circuit is larger than a preset auxiliary power supply voltage. According to the scheme above, the input voltage range of the input circuit in the interface circuit can be improved.

An isolated power converter comprising a transformer arranged in such a way that the mirrored primary voltage on the secondary side has a positive potential relative to ground, said converter comprising a derivating net arranged to cause the second transistor to conduct in dependence of the voltage across the secondary winding, the source of the second transistor being connected to the negative end of the secondary winding, the drain of a third transistor further being connected to the positive end of the secondary winding, a second capacitor and a second resistor being connected between the gate and the source of the third transistor, a third resistor connected between the second resistor and the drain of the second transistor, a third capacitor connected between the sources of the second and third transistors to provide a first output voltage on one terminal of the third capacitor and a second output voltage on the other terminal of the third capacitor.

The invention provides an electromagnetic switch feedforward feedback control module with ultra-wide working voltage. After EMI filtering and rectifying filtering, the power supply is connected with afirst switching transistor. The first switch tube is connected to one end of the coil of the electromagnetic switch; The other end of the coil is connected with a second switch tube; The second switch tube is connected to the main control processor through the first current sampling circuit as a feedback variable; The first current sampling circuit is respectively connected with both ends of thecoil through a first freewheeling diode and a fast demagnetization circuit. After EMI filtering, rectifying and filtering, the power supply is connected to the main control processor through the second voltage sampling circuit as a feedforward variable. Feed forward variable and feedback variable form weak power PWM signal in the main control processor. The weak power PWM signal of the main control processor is transmitted to the first switch transistor through the first high voltage side floating drive circuit. As that direct current bus voltage feedforward and the coil current feedback are introduce in the invention, the power disturbance can be effectively respond to, the harmonics of the coil current can be restrained, the ripple pollution can be prevented, and the high-frequency noiseof the coil can be reduced.

An input circuit has a differential amplification circuit which converts a differential signal to a single end signal to output the single end signal, an attenuation circuit which attenuates a first input signal to output the attenuated signal to the differential amplification circuit, a capacitor in which one end thereof is connected to a first input terminal to which the first input signal is inputted, and another end thereof is connected to an output side of the differential amplification circuit, a buffer to which the single end signal outputted from the differential amplification circuit and a signal transmitted through the capacitor are inputted, and which outputs the output signal, and a feedback circuit which outputs a signal based on an output signal outputted from the buffer and the second input signal to the differential amplification circuit.

A method for extending the linear range of operation of an amplifier includes monitoring a transistor voltage of a transistor of an amplifier. The transistor is coupled to a variable current source applying a bias current to the transistor. The method continues by monitoring an output voltage of the amplifier and by determining whether the transistor voltage is within a predetermined range of the output voltage. If the transistor voltage is not within a predetermined range of the output voltage, the method continues by decreasing the bias current applied to the transistor. If the transistor voltage is within a predetermined range of the output voltage and if the bias current has not previously been decreased, the method continues by increasing the bias current applied to the transistor.

The invention relates to a high-precision fast-integration type AD (Analog-Digital) converter based on a single chip microcomputer, comprising an integrated signal control circuit, an integrator, a level comparison circuit and a single chip microcomputer. The integrated signal control circuit comprises resistors R1, R2, R3 and R4 and analog electronic switches K1, K2, K3 and K4; the integrator comprises an operational amplifier and a capacitor C; and the voltage comparison circuit comprises three high-speed comparators, i.e. a low voltage comparator, a high voltage comparator, a zero-crossingcomparator; and UNK, SC, FC and RC signals output by the single chip microcomputer are respectively connected with the controlled end of the analog electronic switches K1, K2, K3 and K4 and control the on-off of the analog electronic switches. The converter is directly controlled by the single chip microcomputer, and an external counter and a programmable logic device are omitted, thus, the circuit is simplified, the cost is reduced, and the converter is more easily combined with an AD application system.

A differential amplifier includes a pair of input transistors, a pair of load transistors, a pair of impedance devices, a pair of auxiliary input transistors, and a pair of shield transistors is provided. The input transistors provide two input terminals. The load transistors provide two output terminals and two first terminals connected to first voltage. The impedance devices are coupled between the output terminals in series. The auxiliary input transistors have two control terminals respectively connected to the input terminals, two first terminals, and two second terminals. The input transistors and the auxiliary input transistors have reverse conductive type. The shield transistors has a pair of control terminals, a pair of first terminals respectively connected to the second terminals of the auxiliary input transistors and coupled to a second voltage through a pair of current sources, and a pair of second terminals respectively connected to the output terminals.