901 results about "Error amplifier" patented technology

The invention discloses a control circuit of an electronic load, the electronic load and a power supply test system. The circuit comprises an MCU; the signal output end of the MCU is connected with the input end of the DAC module; the closed-loop control circuit comprises a first error amplifier, a mutual inductor, an MOS (Metal Oxide Semiconductor) tube, a current sampling resistor and a power supply end VBUS; a mutual inductor is arranged between a first error amplifier and an MOS tube of the closed-loop control circuit, a power supply end VBUS is connected with a drain electrode of the MOS tube through a primary side of the mutual inductor, a first secondary side of the mutual inductor feeds back an input signal of the first error amplifier, and a second secondary side of the mutual inductor feeds back a driving signal of the first error amplifier to the MOS tube. According to the invention, the dynamic response speed when the electronic load pulls the high-frequency current can be improved, and the test requirements of high precision and high dynamic response are met.

The invention is suitable for the technical field of LED backlight driving, and provides a starting control circuit for LED backlight driving, a chip and a display device. The starting control circuit of the LED backlight drive comprises a detection selection module, an error amplification module, a first change-over switch module, a control module, a second change-over switch module, a logic drive module, a feedback module and a first switch module. When each first voltage is in a preset range, the first change-over switch module is used for conducting the first input end of the error amplification module and the output end of the error amplification module. And the second change-over switch module is used for transmitting the overcurrent protection signal to the logic driving module. When the detection voltage is larger than the first reference voltage, the first change-over switch module is used for conducting the first input end of the error amplifier and the detection selection module. And the second change-over switch module is used for conducting the control module and the logic driving module. Therefore, the Boost has more response time to respond to the rapid change of the LED.

The invention relates to the technical field of power supply starting, in particular to a power supply starting system with ultra-large capacitive load energy and a starting control method.The power supply starting system comprises a power supply body and a load module, the output end of the power supply body is coupled with the load module, and the power supply body comprises a constant-current control module; the detection module is used for detecting output current in a power supply starting process and transmitting a detection result to the MCU control unit; the MCU is used for generating a PWM (Pulse Width Modulation) signal according to the received output current signal so as to control the starting current to be constant; the PWM driving module is used for adjusting the output current of the power supply according to the PWM signal generated by the MCU control unit, and the error amplifier is used for amplifying the output current signal detected by the constant current control module and transmitting the output current signal to the MCU control unit; the current sensor is used for detecting the output current of the power supply in real time; and the MOSFET switch is used for adjusting the output current of the power supply according to the PWM signal. According to the invention, the problem of restarting due to overcurrent protection caused by a large capacitive load in a power supply starting process is solved.

The invention provides a three-loop on-chip integrated low-dropout linear voltage regulator, which comprises a three-port source follower type voltage follower, which comprises a first anti-phase end, a normal phase end, a second anti-phase end and a first output end; the error amplifier is used for comparing a reference voltage with an output voltage so as to provide a first control signal for the first anti-phase end; the self-feedback bias module is used for receiving an internal voltage signal of the three-port source follower type voltage follower so as to provide a second control signal for the second anti-phase end; the grid electrode of the power tube is connected with the output end, the source electrode is connected with the power supply voltage, and the drain electrode serves as a second output end and is used for receiving the adjusting signal output by the first output end; the output driving current of the power tube is adjusted based on the adjusting signal; and the bias module is used for providing bias voltage for the three-port source follower type voltage follower and the error amplifier. The transient response performance of the voltage stabilizer can be improved under the condition of no off-chip large capacitance.

A soft start circuit of a synchronous boost DC-DC converter is used for restraining current overshoot and voltage overshoot of the synchronous boost DC-DC converter in the starting process and comprises a first soft start module and a second soft start module. The first soft start module belongs to system open-loop work, and suppresses a channel length modulation effect through the same drain end voltage of a clamping matching tube and a power upper tube, so as to obtain a precisely controlled charging current. A second soft start module belongs to system closed-loop work, and the method comprises the following steps: in the first stage, VOUT partial voltage is synchronized; in the second stage, constant-current charging is carried out; and in the third stage, the error amplifier vref rises gently through preset voltage RC charging. According to the invention, current overshoot and voltage overshoot are effectively suppressed through two soft start stages, and the starting circuit has a wide application prospect in the field of starting circuits.

A half-bridge driver circuit periodically repeats switching cycles by closing a first FET via a first drive signal, detecting an instant when a current flowing through the first FET reaches a threshold and then opening the first FET and closing a second FET via a second drive signal. An error amplifier generates a control voltage by comparing a feedback signal with a reference signal, and a variable current generator generates a first current as a function of the control voltage. The error amplifier includes a proportional-integral controller, and a slope compensation circuit that generates a second current as a ramp signal. The threshold is generated by subtracting the second current from the first current. In response to detecting the instant, the second current is sampled and a signal indicative of the threshold is generated by subtracting the sampled second current from the first current.

A light-emitting element drive device includes, for example, a current sense amplifier configured to generate a current detection signal corresponding to a difference between a sense voltage corresponding to an inductor current (and thus an output current) supplied to a light-emitting element and a predetermined current setting signal (e.g., an offset voltage corresponding to a set current), an error amplifier configured to generate an error signal such that a direct-current component of the current detection signal has a zero value, a comparator configured to generate a set signal by comparing the current detection signal with the error signal, and a driver configured to perform feedback control of the output current in accordance with the set signal.

The utility model discloses a digital auxiliary simulation LDO circuit without an off-chip capacitor. A simulation main loop of the circuit comprises an error amplifier, a buffer stage circuit, a simulation power stage circuit and a VG voltage detection circuit. The digital auxiliary loop includes a digital control logic circuit, a ring oscillator circuit, and a digital power stage circuit. By introducing the digital power adjusting tube, the parasitic capacitance of the grid electrode of the analog power tube is reduced, the pole of the grid electrode is located at high frequency, and on the basis, the super source follower is added to push the pole to higher frequency, so that the circuit has better loop stability. In a steady state, the digital auxiliary loop is forbidden, and the analog main loop can ensure strict adjustment, low quiescent current and no switching noise at the output end; when a load current suddenly changes, a ring oscillator in the digital auxiliary loop is called to generate a clock signal, and the number of conducted digital power tubes is changed, so that response time is not limited by a clock period, dependence on an external clock is avoided, meanwhile, voltage precision and rapid transient response are guaranteed, and static power consumption of the circuit is reduced.

The invention discloses a fast transient response Buck converter based on AOT control, which is compatible with the advantages of current mode control and AOT control, and is characterized in that an error amplifier is added in a negative feedback control loop, so that the precision of output voltage is improved, a current loop is stable, and the series resistance value of an output capacitor is not specifically limited; the change rate of the switching frequency in heavy load is reduced by using the improved self-adaptive turn-on time module, and the change of the switching frequency under different load current conditions is ensured to be small. The transient enhancement module is used for judging the output voltage, it is ensured that when the load current suddenly changes, the output voltage is fast and stable, overshoot and undershoot are reduced, and therefore the overall stability and reliability are improved. The sleep detection module Sleep is used for detecting a switching tube driving signal VCOMP so as to control the Buck converter to enter a dormant state, and therefore the purposes of reducing power consumption and improving efficiency are achieved.

Disclosed is a voltage regulator including a power supply terminal and an output terminal. The voltage regulator includes an NMOS transistor including a drain electrode connected to the power supply terminal, a gate electrode, and a source electrode connected to the output terminal; a first regulating circuit including a voltage divider circuit connected between the output terminal and ground, and configured to generate a feedback voltage based on the output voltage of the output terminal, and an error amplifier including a first input terminal, a second input terminal, and an output terminal connected to the gate electrode; and a second regulating circuit including a charge pump having an enable control terminal and an output terminal connected to the gate electrode, wherein the charge pump is configured to be selectively turned on based on the enable control signal to regulate the output voltage of the voltage regulator.

The invention provides a voltage stability control method for a multi-output switching power supply, which comprises the following steps of: sampling a main output channel in real time to obtain a voltage signal; the voltage signal is processed through a wide bandwidth error amplifier, a main channel adjusting signal is generated, and the main channel adjusting signal is used for driving a main power switch device; receiving an input voltage fluctuation frequency band of an auxiliary channel, a load current transient change gradient and a frequency spectrum coupling characteristic of a main channel adjusting signal through a dynamic prediction model, and generating an auxiliary channel adjusting signal with a phase lead compensation characteristic; a cross coupling active offset mechanism is constructed, time domain-frequency domain characteristics of coupling interference are extracted through a high-precision differential detection circuit, amplitude-frequency adjustable reverse correction signals are generated in real time through an adaptive compensation algorithm and injected into control nodes of an auxiliary output channel, and dynamic decoupling and ripple suppression are carried out. According to the method, high-stability control of multi-channel voltage under all working conditions is realized, and the dynamic response speed and the anti-interference capability are improved.

The invention discloses a low-dropout linear voltage regulator which is totally divided into three parts, the first part is an error amplifier, and it is guaranteed that the output voltage of the low-dropout linear voltage regulator is kept unchanged under different load currents; the second part is a source following current output stage, the output current is divided into two branches, one branch is supplied to the base electrode of an NPN triode, and the other branch is supplied to a first NMOS tube connected with a diode; and the third part is a zero point tracking part, the principle of the zero point tracking part is to obtain a current which is proportional to the current flowing to the base electrode of the NPN triode so as to obtain a zero point, and the frequency of the zero point is increased along with the increase of the load current for frequency compensation. The three parts, a power NPN triode, a partial pressure feedback resistor and a plug-in capacitor form a whole circuit. According to the invention, the driving current can reach the ampere level, the requirement of the whole circuit on the value of the equivalent series resistance of the external capacitor is reduced, and the resistance value range of the equivalent series resistance of the external capacitor is expanded.

The invention discloses a wide input voltage range current-limiting protection circuit suitable for a load switch. The wide input voltage range current-limiting protection circuit comprises a power tube MN1, a sampling tube MN3, a sampling resistor Rsense, a power switching module, a sampling module, an error amplifier EA, a resistor Rload and a capacitor Cload. The whole loop can achieve the current-limiting protection function within the power supply voltage range of 0.5-5.5 V, and the current-limiting protection function can also be achieved when the output is as low as 0V. Different from a current-limiting protection circuit in a traditional load switch, the current-limiting protection circuit has the advantages that a sampling loop is formed by sampling the potential of the drain end, and the problem that the loop cannot work normally when the output voltage is too low due to sampling of the potential of the source end is solved; and secondly, a mode of combining a power supply switching module and a rail-to-rail operational amplifier is designed, so that a current-limiting protection function can be realized in a wider input voltage range.

A DC / DC converter includes a converter stage to receive an input voltage and to provide an output voltage from the input voltage in accordance with a modulated drive signal. The converter stage further provides a feedback voltage representing the output voltage. A controller circuit includes an error amplifier to receive the feedback voltage and a reference voltage and to provide an error signal based on the feedback voltage and the reference voltage. A PWM modulator receives a clock signal and the error signal and generates a modulated signal based on the clock signal and the error signal, and a logic circuit receives the modulated signal and generates the drive signal for the converter stage based on the modulated signal so that the drive signal has the same duty cycle as the modulated signal, when the duty cycle of the modulated signal is not smaller than a minimum duty cycle value.

The invention relates to the technical field of chip detection, and discloses a high-reliability power supply chip circuit fault detection system, which comprises a built-in self-test architecture integrated in a low dropout regulator chip, and the built-in self-test architecture is provided with a first test mode and a second test mode which are switched based on a mode switching control circuit. The detection module is used for detecting key performance parameters of an error amplifier sub-circuit in a low dropout linear regulator chip, the detection module is used for measuring the direct current loop gain, the offset voltage, the common mode rejection ratio and the power supply ripple rejection ratio of the amplifier in the first test mode, and the detection module is used for measuring the unity gain bandwidth of the amplifier in the second test mode. According to the invention, through the design of a built-in self-test architecture and two test modes, abnormal states such as differential circuit imbalance and feedback loop fault can be identified in a bare chip stage, chips with poor performance are rejected in advance, and the LDO chip is ensured to reach a ppb-magnitude high reliability standard.

The invention relates to the technical field of LDO circuits, and discloses a dynamic zero compensation circuit which comprises an error amplifier, a zero compensation module, a power tube module and a dynamic bias voltage generation module. The input end of the error amplifier receives a reference voltage Vref and a resistance feedback voltage FB, and the output end of the error amplifier provides a control voltage for the power tube module; the zero point compensation module is electrically connected with the output end of the error amplifier, the dynamic bias voltage generation module generates dynamic bias voltage through dynamic current of the mirror image power tube module and feeds back the dynamic bias voltage to the zero point compensation module to adjust a compensated zero point in real time, and the dynamic bias voltage generation module tracks the power tube current to compensate the zero point. The zero frequency of the zero compensation module is adjusted in real time, and a compensation zero point is dynamically matched with output pole drift, so that the phase margin of a loop in a wide load range is sufficient, the oscillation risk is effectively suppressed, and stable work of the LDO circuit is guaranteed.

The invention discloses a low dropout linear regulator with a wide dropout range, which is characterized in that an error amplifier is supplied with power by output voltage of the low dropout linear regulator, and a common-gate buffer is supplied with power by input voltage of the low dropout linear regulator, so that a direct interference path of the input voltage to the output only exists in a common-gate buffer stage and an output stage; and the power supply rejection ratio is improved. The common-gate buffer solves the problem of margin loss caused by a traditional source follower circuit, a positive feedback loop arranged in the common-gate buffer is used for improving the slew rate of a driving signal VPGATE and providing a certain gain, and therefore the problem of margin under low dropout is solved, and the reliability of the driving circuit is improved. And the compensation circuit can adjust the compensation amount of the low-dropout linear regulator when the input voltage is higher than a preset threshold value, so that the stability of the low-dropout linear regulator under different working conditions is improved.

An isolated DC-DC converter is provided, including a full-bridge switching stage, a resonant network, a transformer, an output stage, an output stage, an error amplifier, a feedforward controller, a charge sensor and a switch controller. The output stage generates an output signal, wherein the output signal is an output voltage or output current. The error amplifier generates an error signal based on the output signal and a reference signal, wherein the reference signal is a reference voltage or reference current. The feedforward controller senses an input voltage of the full bridge switching stage, and generates a feedforward control signal based on the sensed signal. The charge sensor generates at least one charge sensing signal. The switch controller generates and provides switch control signals to the plurality of active switches in charge control mode based on at least the error signal, the feedforward control signal and the charge sensing signal.

A low-dropout regulator having an output voltage switching circuit is provided. In the low-dropout regulator, a low-dropout linear regulator circuit outputs a regulating signal according to a voltage difference between a second terminal of a transistor and a regulating threshold voltage signal or a reference voltage. In the low-dropout regulator, a switch error amplifier circuit outputs a pull-up control signal according to a voltage difference between the second terminal of the transistor and a voltage pull-up switching signal. When a voltage selector circuit of the low-dropout regulator selects the regulating signal, the transistor operates to regulate an output voltage of the low-dropout regulator according to the regulating signal. When the voltage selector circuit selects the pull-up control signal, a switch component is turned on by the pull-up control signal such that the output voltage of the low-dropout regulator is directly pulled up by an input voltage.

The invention relates to the technical field of power management in an integrated circuit, in particular to an ultra-low noise LDO with a programmable current limit and quick start. Comprising a reference current generating circuit, an RC filter, a first negative feedback loop, a control resistor, a comparison control circuit, a programmable current limiting circuit, a sampling tube MP0 and a first switch current source. The first negative feedback loop comprises an error amplifier, a buffer stage and a power tube MP1; before the LDO is started, current limit programming is achieved; after current limit programming is finished, the LDO starts to start, an LDO quick start control signal is generated through the programmable current limit circuit, an extra charging path is provided for the RC filter circuit through the constant current source, and quick start of the ultralow-noise LDO is achieved; when the output voltage of the LDO is close to a preset value, the quick starting circuit is closed; according to the LDO, the current limit is adjustable, the protection capability to the rear stage is improved, and the reliability of the whole system is enhanced.

The invention discloses a fast dynamic response system and method of a DCDC converter, relates to the technical field of DCDC converters, and solves the technical problem that the detection of load changes in the prior art usually relies on the change of output voltage, while ignoring the limitation of the physical characteristics of capacitor voltage changes, resulting in delayed detection results. The invention jointly judges the load condition of a DCDC topology through an output capacitor current detection circuit and an overshoot or undershoot detection circuit. If the output voltage generated by the DCDC topology exceeds or is lower than the upper threshold voltage or the lower threshold voltage of the overshoot or undershoot detection circuit, the output voltage compensation circuit is turned on to discharge or charge the output capacitor. The reference voltage selection circuit selects a low voltage reference or a high voltage reference, and the GM adjustable error amplifier selects a high bandwidth. The control logic circuit adjusts the duty cycle of the DCDC topology. Timely detection and response to load mutations are achieved, and the power supply stability of the system is effectively improved.

The invention discloses a peak current and valley current controlled three-mode buck-boost converter, which comprises a power level circuit, an error amplifier, a slope compensation module, a current sampling module, a PWM (Pulse Width Modulation) comparator, a mode control module and a switching control module, and is characterized in that the power level circuit obtains an output voltage according to an input voltage and outputs a sampling voltage; the error amplifier outputs a control signal according to a comparison result of the sampling voltage and the reference voltage; the mode control module outputs different enable signals according to the states of the input voltage and the output voltage; the slope compensation module outputs different compensation voltages when the converter is in different modes; the current sampling module collects the voltage of peak current or valley current according to different modes; the PWM comparator generates a PWM control signal; the switching control module generates a driving signal according to the PWM control signal and different enable signals so as to switch different modes. The mode switching efficiency can be improved, the duty ratio can be reduced, and then output voltage ripples are reduced.

Current balancing techniques. In an example, a circuit includes a synchronization terminal, an error amplifier, and a clock generator. The error amplifier is configured to generate a first control voltage signal based on a reference voltage and a power converter output voltage. The clock generator is configured to produce an outgoing clock signal having an outgoing clock frequency. The circuit further includes an encoder, a frequency detector, and a decoder. The encoder is coupled to the clock generator and synchronization terminal, and configured to encode the outgoing clock signal based on the first control voltage signal to provide, at synchronization terminal, an outgoing encoded clock signal. The frequency detector is coupled to synchronization terminal and configured to derive, from an incoming encoded clock signal, an incoming clock frequency. The decoder is coupled to synchronization terminal and configured to derive, from the incoming encoded clock signal, a second control voltage signal.

The invention provides a turn-back type current-limiting protection circuit and a low dropout regulator, and belongs to the technical field of integrated circuits, and the turn-back type current-limiting protection circuit is characterized in that a first sampling resistor outputs a first current according to a sampling signal of a load current, a first bias current and a gated second bias current; the second sampling resistor outputs a second current according to the third bias current and the gated fourth bias current; the current comparison network generates a current comparison signal; the common-source amplification module is connected between an output signal of the error amplifier and a grounding end, on-off of the common-source amplification module is controlled by a current comparison signal and a gated low signal, and an output end of the common-source amplification module is connected with a gate driving module of a power tube; the output signal feedback network generates a gating signal according to the input signal, the output signal and the output signal of the error amplifier. The beneficial effects are that constant load current output is realized by detecting the load current change of the power tube and adjusting the grid voltage of the power tube, and the grid voltage clamp of the power tube is positioned at a safe level by utilizing output voltage feedback, so that turn-back type current limiting protection is realized.

The invention belongs to the technical field of electronic circuits, and provides a negative voltage charge pump circuit, a switching power supply converter and electronic equipment. A reference voltage generation module, a comparison module, a fourth driving module, a fifth power tube, a sixth power tube and a seventh power tube are additionally arranged on an existing charge pump. The reference voltage generation module is used for generating third reference voltage, namely threshold voltage when the negative-voltage charge pump circuit enters the light load, then the comparison module is used for comparing the third reference voltage with error voltage output by the error amplifier, and whether the negative-voltage charge pump circuit enters the light-load working condition or not is judged; when the negative-voltage charge pump circuit enters a light-load working condition, the large-size power tube and the driving module thereof are closed, and only the small-size power tube works, so that other performances of the negative-voltage charge pump circuit are ensured, the working current of the negative-voltage charge pump circuit in the light-load state is greatly reduced, and the working efficiency of the negative-voltage charge pump circuit is improved. Therefore, the conversion efficiency of the charge pump circuit in light load is improved.

The invention provides a BUCK converter and a variable gain error amplification circuit, and is applied to the technical field of power supply chips and BUCK converters. An error amplifier is improved into a variable gain error amplifier in the BUCK converter, and error amplification gain switching is carried out on whether load switching (such as overshoot / undershoot conditions) exists at an output end or not through a feedback detection circuit, for example, when it is detected that the output is in a load switching state; the error amplifying circuit rapidly enters an overshoot / undershoot mode, the transient current of the response branch is increased, the response speed is increased, the low transient voltage is achieved, the fast response characteristic is achieved, and the advantage of high efficiency can be continuously kept in the normal working process.

The invention discloses an LED open circuit protection control system and a control method thereof. The circuit comprises a logic control module, a constant turn-on time module, a driving module, an NMOS tube MN1, an NMOS tube MN2, an inductor L, a current sampling resistor Rsense, a capacitor C2, an operational amplifier OP2, an error amplifier EA, a comparator CMP1, a loop compensation network, a switch S1, a filter network, a selector MUX, an operational amplifier OP1, a PMOS tube MP1, a minimum turn-off time detection circuit, an output overvoltage detection circuit, an AND gate AND1 and a phase inverter INV1. When the output LED is in an open circuit, the output voltage of the error amplifier EA is clamped at a proper voltage value required by normal operation of the system, so that the problem of inductive current peak during fault removal in the prior art is solved, and the reliability of the system is improved.

The invention relates to the technical field of switching power supplies, and relates to a transient response circuit, a switching converter, a chip and electronic equipment. The transient response circuit comprises a first adjusting unit, a second adjusting unit and an error amplifier, and the first adjusting unit and the second adjusting unit are both connected with the output end of the error amplifier. The first adjusting unit is used for controlling the first error voltage to be increased when the first error voltage output by the error amplifier is smaller than a first error voltage threshold value; the second adjusting unit is used for controlling the first error voltage to be increased when the first error voltage output by the error amplifier is greater than a second error voltage threshold value; the first error voltage threshold value is smaller than the second error voltage threshold value. Therefore, the problem that the load transient response circuit cannot work normally due to overshoot of the output voltage can be improved, and the stability of the circuit is further improved.

A semiconductor device includes: a current sense circuit that generates a current sense signal corresponding to a monitoring target current; an error amplifier; a comparator; and a controller. The current sense circuit includes: a differential amplifier of a current output type; a first input resistor connected between a first input terminal of the differential amplifier and a first current sense terminal; a second input resistor connected between a second input terminal of the differential amplifier and a second current sense terminal; an output resistor configured to be connected to the output terminal of the differential amplifier; a first feedback current path across which a first feedback current is passed between the first input terminal and the output terminal of the differential amplifier; and a second feedback current path across which a second feedback current is passed between the second input terminal of the differential amplifier and the output terminal.

An error amplifier includes a first transistor having a first error amplifier input and having first and second current terminals, a second transistor having a second error amplifier input and having third and fourth current terminals, a first resistor coupled between a supply voltage terminal and the first current terminal, and a second resistor coupled between the supply voltage terminal and the third current terminal. The error amplifier has a second stage circuit coupled to the first and second resistors. The second stage circuit has an error amplifier output. The second stage circuit is configured to cause less current to flow through the second stage circuit than a current that flows through either of the first or second resistors or the first or second transistors.