Abstract: A vehicle system is provided with an input pin, an interface unit and a microcontroller. The input pin connects to an external power source or ground through an external switch. The interface unit is adapted to connect to the input pin in a test configuration, and in a normal configuration for providing a wetting current to the external switch, and in a test configuration. The microcontroller is programed to: configure the interface unit in the normal configuration in response to input pin characteristics, reconfigure the interface unit in the test configuration, measure a test voltage of the interface unit, and generate output indicative of a status of the external switch based on a comparison of the test voltage to a reference voltage.

Abstract: A liquid level detection system for determining a liquid level includes a level sensor configured to be at least partially disposed in a liquid storage vessel and exposed to liquid. A first optoelectronic interface is operatively connected to the level sensor for providing power thereto. A second optoelectronic interface is operatively connected to the first optoelectronic interface. A fiber optic cable optically connects the first optoelectronic interface to the second optoelectronic interface to provide photonic power to the first optoelectronic interface and to transmit data from the first optoelectronic interface to the second optoelectronic interface.

Abstract: A constant on-time pulse width control-based apparatus capable of detecting a transient event of a voltage converter includes a specific comparator, a logic circuit, and a controller. The specific comparator generates a logic control signal to the logic circuit according to two resultant signals of the controller. The logic circuit generates a pulse control signal with an on-time pulse width to charge an output capacitor according to the logic control signal. The controller generates the two resultant signals to the specific comparator by generating a voltage ramp signal and amplifying an output voltage ripple signal based on a reference voltage, and detects the transient event to dynamically adjust the on-time pulse width of the pulse control signal according to the amplified output voltage ripple signal.

Abstract: A discrete-time analog circuit comprises: a voltage-current conversion circuit that converts an input voltage signal into a current signal and outputs the current signal; and a charge inverting circuit that is connected to an output terminal of the voltage-current conversion circuit to perform charge sharing. The charge inverting circuit includes 2M capacitors (M is an integer greater than or equal to 1) that are provided parallel to each other. In accordance with a predetermined sampling interval, one of the 2M capacitors repeats: (1) sharing input charge that is input by the current signal, (2) holding at least part of the input charge, (3) inverting a polarity of the held charge and connecting to the output terminal to share the held charge, and (4) holding remaining charge. At time period when one of the 2M capacitors is connected to the output terminal, the other capacitor(s) of the 2M capacitors is not connected to either of an input terminal and the output terminal.

Abstract: Waveform generation circuits are provided. A waveform generation circuit includes a waveform generation block configured to generate a waveform signal corresponding to a driving control signal, and a control signal generation block configured to generate the driving control signal to compensate the waveform signal for an environmental factor affecting the waveform generation circuit.

Abstract: A ramp generator circuit, e.g. foreign analog-to-digital converter. The ramp generator circuit has first and second current sources that are maintained in the on condition whether they are being used or not. A switched capacitor connects to the current source in order to create a multi-slope ramp.

Abstract: A fully integrated ramp generator circuit includes a first current generator that sources current to first capacitor through a first transistor that is gate controlled by the complement of a periodic signal. The ramping voltage stored on the first capacitor is buffered to an output node as a ramp output signal. A second transistor couples the output node to the first current generator and is gate controlled by the periodic signal. The periodic signal is generated at the output of a flip-flop that receives an input clock signal and reset signal. The reset signal is generated by a comparator circuit operable to compare the voltage on a second capacitor to a reference. The second capacitor is charged by a second current source and discharged by a third transistor that is gate controlled by the periodic signal.

Abstract: A sawtooth wave generating circuit that outputs a sawtooth wave signal after calibration and a switch mode power supply device including the sawtooth wave generating circuit is disclosed. The sawtooth wave generating circuit includes a capacitor, a calibration circuit, a charging circuit, discharging circuit and a control unit. The calibration circuit feedbacks a sawtooth wave signal, generates a plurality of voltage signals based on the sawtooth wave signal, and selects one of the voltage signals to generate a calibration output signal. Therefore, the sawtooth wave generating circuit generates a stable sawtooth wave signal regardless of operating conditions.

Abstract: A circuit includes a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a predetermined voltage level. A first stage set of capacitors is operatively coupled to the level-crossing detector. A ramp circuit is operatively coupled to the set of series-connected capacitors. A second stage set of capacitors is operatively coupled to the first stage set of capacitors and the ramp circuit. The ramp circuit includes a feedback capacitor and a preset switch to provide a linear ramp output.

Abstract: Disclosed are a ramp signal generator and an image sensor. The ramp signal generator includes: a comparator comparing a first bias voltage input to a first input terminal and a second bias voltage input to a second input terminal and outputting a ramp signal from an output terminal; a ramp signal adjustment unit including a plurality of switched capacitors made up of switches and capacitors connected in series, and connected in parallel between a first input terminal of the comparator and an output terminal of the comparator; and a controller switching the switches of the plurality of switched capacitors to adjust the ramp signal output from the comparator such that the ramp signal becomes nonlinear over time.

Abstract: A buck-boost power converter includes a power stage to convert an input voltage to an output voltage, an error amplifier to generate an error signal according to a reference voltage and a feedback signal proportional to the output voltage, a ramp generator to provide two ramp signals, and two comparators to generate two control signals according to the error signal and the two ramp signals to drive the power stage. By using feed-forward technique, one of the two ramp signals has a peak varying with the input voltage and the other ramp signal has a valley varying with the input voltage, so that the power converter has fast line response.

Abstract: A ramp generator circuit, e.g. foreign analog-to-digital converter. The ramp generator circuit has first and second current sources that are maintained in the on condition whether they are being used or not. A switched capacitor connects to the current source in order to create a multi-slope ramp.

Abstract: The sawtooth wave generation circuit includes: a switch circuit configured to switch a connection state thereof between a first connection state, in which a current from a current source is flowed from a first terminal of the output capacitor to a second terminal of the output capacitor, and a second connection state, in which a current from the current source is flowed from the second terminal of the output capacitor to the first terminal of the output capacitor; a switch control circuit configured such that, in each connection state of the switch circuit, if an output voltage has reached a predetermined threshold which is set in relation to an intermediate voltage, the switch control circuit controls the switch circuit to switch the connection state to the other connection state at least during a part of a predetermined period thereafter.

Abstract: A method and apparatus to drive a load using a pulse-width modulated (PWM) signal and spread a spectrum of the PWM signal across a plurality of frequencies while maintaining a constant duty cycle for the load.

Abstract: An integrated circuit includes a saw-tooth generator including a saw tooth node configured to have a saw-tooth voltage generated thereon; and a first switch having a first end connected to the saw tooth node. The integrated circuit further includes a second switch coupled between an output node and an electrical ground, wherein the first switch and the second switch are configured to operate synchronously. A first current source is connected to the saw tooth node. A second current source is connected to the output node.

Abstract: A first periodic signal generation circuit generates first periodic output signals. A second periodic signal generation circuit generates second periodic output signals. A first multiplexer circuit receives the first and the second periodic output signals. An interface circuit coupled to external pins generates a third periodic output signal based on a periodic signal selected by the first multiplexer circuit. A second multiplexer circuit receives the third periodic output signal at an input. A first periodic feedback signal provided to the first periodic signal generation circuit is based on a signal selected by the second multiplexer circuit. A third multiplexer circuit receives the third periodic output signal at an input. A second periodic feedback signal provided to the second periodic signal generation circuit is based on a signal selected by the third multiplexer circuit.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an integrating circuit. The integration circuit receives input from the square waveform clock circuit and generates a triangular waveform output. A feedback circuit is operatively connected to the integrating circuit to reduce the audio band noise content in the triangular waveform output. The feedback circuit acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: An integrated circuit includes a saw-tooth generator including a saw tooth node configured to have a saw-tooth voltage generated thereon; and a first switch having a first end connected to the saw tooth node. The integrated circuit further includes a second switch coupled between an output node and an electrical ground, wherein the first switch and the second switch are configured to operate synchronously. A first current source is connected to the saw tooth node. A second current source is connected to the output node.

Abstract: A waveform generation circuit includes: a waveform generation block configured to generate a waveform signal corresponding to a driving control signal; and a control signal generation block configured to generate a driving control signal for compensating the waveform signal for an environmental factor reflected into the waveform generation circuit.

Abstract: An apparatus is provided. The apparatus comprises a first current source and a second current source that charge and discharge a capacitor. Coupled between the capacitor and the second current source is a switch that can be actuated and deactuated by a controller. Preferably, the controller is coupled to the capacitor and receives a first threshold voltage and a second threshold voltage so that it can actuate the switch if the voltage across the capacitor is greater than the first threshold voltage and deactuate the switch if the voltage across the capacitor is less than the second threshold voltage. Additionally, there is a comparator that is coupled to the capacitor that compares the voltage across the capacitor to a reference voltage, and there is a a multiplexer that is coupled to the capacitor and that is coupled to the comparator.

Abstract: A sawtooth generator circuit comprises a first triangular waveform generator with equal ramp up and ramp down rates and a second triangular waveform generator with equal ramp up and ramp down rates and which are equal to the ramp up and ramp down rates of the first triangular waveform generator. The first and second triangular waveform generators are controlled to be 180 degrees out of phase. A switching arrangement alternately switches the increasing or decreasing ramps of the first and second triangular waveform generators to an output of the sawtooth generator circuit. The invention provides a sawtooth generator circuit which is suitable for high frequency applications, with low current consumption and low ground bounce. A very fast falling edge can be obtained.

Abstract: There is provided a filter circuit that includes a flying capacitor and a capacitor that is provided in parallel with the flying capacitor, between an input terminal and an output terminal of the flying capacitor. As the capacitor that has a predetermined capacity is provided between the input terminal and the output terminal of the flying capacitor, it is possible to provide steep attenuation characteristics in the filter circuit provided with the flying capacitor.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: A waveform generation circuit includes: a waveform generation block configured to generate a waveform signal corresponding to a driving control signal; and a control signal generation block configured to generate a driving control signal for compensating the waveform signal for an environmental factor reflected into the waveform generation circuit.

Abstract: A circuit includes a pulse transformer having primary and secondary windings. An oscillating waveform is applied to the primary winding to induce an oscillating waveform at the secondary winding. A transistor in series with a first resistor is coupled between the secondary winding and the ground. An R-C network formed by a second and a third resistor and a capacitor is coupled to a base junction of the transistor. The R-C network causes a slow, tapered linear pinch off of the transistor's conductance to enable the circuit to output a triangular waveform, which is characterized by a relatively short linear rise time followed by a substantially long linear fall time. The R-C network is coupled to the secondary winding via a first and a second diode, respectively.

Abstract: A triangular wave generating circuit includes: an integrating unit including a capacitor, the integrating unit having an output for providing a triangular wave signal; first and second constant current sources for charging and discharging the capacitor; a switch unit for coupling the first and second current sources to the integrating unit to charge and discharge the capacitor in response to an internal clock signal; a high/low level limiter including first and second comparing units for comparing the output of the integrating unit with upper and lower triangular wave peak limit reference voltages, respectively, and providing output signals indicating when the output of the integrating unit coincides with the peak limit reference voltages; a clock generator for providing the internal clock signal in response to the comparing unit output signals; and means for varying a peak-to-peak swing of the triangular wave signal over time to synchronize the internal clock signal with an externally supplied clock pulse.

Abstract: A low power servo-controlled single clock ramp generator (100) includes a fast switched comparator (102), charge pump (110) and voltage-to-current converter (120) connected to provide a feedback control mechanism under control of a pulse comparison clock signal (pulse_comp) and a reset pulse clock signal (rst_pulse) that are generated from a single input clock signal (clkin) so that there are well defined time intervals between pulses in the pulse comparison clock signal and the reset pulse clock signal, thereby providing a ramp signal (Vramp_out) having a stable, frequency-independent amplitude that is not limited by the reference voltage.

Abstract: Triangular wave oscillation circuits generate A-wave and B-wave with phases opposite to each other, and are capable of independently controlling oscillation levels of the A-wave and the B-wave. A slope switching circuit including an output voltage monitoring circuit, a slope switching control circuit, and an inverter, monitors output voltages of the triangular wave oscillation circuits, to switch an output voltage generation mode of one triangular wave oscillation circuit whose triangular wave reaches a high level, from an up-slope waveform mode to a down-slope waveform mode, and to switch an output voltage generation mode of the other triangular wave oscillation circuit, from the down-slope waveform mode to the up-slope waveform mode. An oscillation level control circuit controls an oscillation level of the other triangular wave oscillation circuit so that the output voltage of the other of the triangular wave oscillation circuit becomes a reference lower limit crest value during the switching.

Abstract: The invention relates to a drive circuit for providing a drive signal (S3) for a switch in a switching converter in a manner dependent on a control signal (S2), the drive circuit comprising at least two groups (22, 30) of circuit components, each group having at least one circuit component, and the circuit components being coupled to one another and designed to provide the drive signal (S3) from the control signal (S2). In this case, voltage is supplied to the circuit components of the first group by means of the control signal, while voltage is supplied to the circuit components of the second group (30) by means of a supply voltage at a supply terminal (K2).

Abstract: A semiconductor device includes a current control circuit for outputting and sinking a current in synchronization with a received clock signal; and a current/voltage conversion circuit having a first capacitor charged and discharged by the current control circuit outputting and sinking the current, respectively, and outputting a triangular wave based on the charge stored in the first capacitor.

Abstract: The teachings presented herein provide a method and apparatus for operating constant on-time DC/DC converters, including pseudo constant on-time variants, with a virtual current-mode slope signal. Use of the slope signal provides, among other advantages and improvements, greater noise immunity and the ability to operate with a wider range of converter output filters. More particularly, incorporating a properly synchronized slope signal into the on-time triggering comparison provides for a maximum slope offset at on-time triggering. Doing so prevent double-pulsing (i.e., erroneous on-time retriggering) and other undesirable behavior of conventional constant on-time DC/DC converters and, as a particular but non-limiting advantage, allows ready and advantageous use of the slope-compensated converter as taught herein with low ESR capacitors in the output filter.

Abstract: A sawtooth wave generating circuit that outputs a sawtooth wave signal after calibration and a switch mode power supply device including the sawtooth wave generating circuit is disclosed. The sawtooth wave generating circuit includes a capacitor, a calibration circuit, a charging circuit, discharging circuit and a control unit. The calibration circuit feedbacks a sawtooth wave signal, generates a plurality of voltage signals based on the sawtooth wave signal, and selects one of the voltage signals to generate a calibration output signal. Therefore, the sawtooth wave generating circuit generates a stable sawtooth wave signal regardless of operating conditions.

Abstract: In a triangular-wave generating apparatus including an output terminal adapted to output an output voltage, an incorporated capacitor connected to the output terminal, a first variable current source adapted to charge the incorporated capacitor and a second variable current source adapted to discharge the incorporated capacitor, a charging/discharging current setting circuit sets a charging current in the first variable current source and sets a discharging current in the second variable current source. A level determining circuit determines whether or not the output voltage reaches one of predetermined voltages, to generate timing signals. A reference clock signal generating circuit generates a reference clock signal for defining a frequency of the output voltage. A charging/discharging current adjusting circuit adjusts the charging current and the discharging current in accordance with the timing signals and the reference clock signal.

Abstract: A circuit for calibrating an oscillating ramp signal to a variable DC reference signal in accordance with an embodiment of the present application includes a circuit for setting a predetermined time period during which a charging capacitor can charge and thus determining a ramp oscillator frequency; a variable current source for providing a charging current to the charging capacitor; a circuit for selecting the charging current fed by the variable current source to said charging capacitor; and a circuit for comparing the oscillating ramp signal to the variable DC reference signal and for supplying a signal to the selecting circuit for controlling the amount of current supplied to said charging capacitor thereby determining the charging voltage across said capacitor at the end of said predetermined time period.

Abstract: A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform.

Abstract: A triangle wave generator with function of spreading frequency spectrum is provided. The triangle wave generator includes a switch control circuit, a current generator, an integrator, and a spread spectrum control circuit. The switch control circuit provides an internal clock and a switch control signal. The current generator is coupled to the switch control circuit and provides charge current according to the switch control signal. The integrator is coupled to the current generator and provides a triangle wave signal. The spread spectrum control circuit is coupled to the switch control circuit and the current generator for providing a current control signal according to the internal clock.

Abstract: The transmitter comprises a signal generator including a capacitor producing the switched signal to be applied to the line. The capacitor is charged by a charging current in response to an input signal so as to define an edge of the switched signal through a feedback loop responsive to the capacitor voltage generating a feedback current having a continuous magnitude that is a progressive function of the capacitor voltage, the charging current being a function of the feedback current. The feedback loop generates first and second feedback voltages one of which is a rising function of the capacitor voltage and the other is a falling function of the capacitor voltage. The feedback current is generated first as a function of one of the feedback voltages and subsequently as a function of the other of the feedback voltages.

Abstract: An accurate intermittent triangular wave signal without waveform distortion is generated by a triangular wave generation circuit 1 including a rectangular wave generation circuit 111 for generating an intermittent rectangular wave signal in which a rectangular wave interval and a direct current interval of a predetermined level are repeated; an integration circuit 12 for generating an intermittent triangular wave signal in which a triangular wave interval and a direct current interval are repeated based on a reference signal and the intermittent rectangular wave signal generated by the rectangular wave generation circuit 111; and a triangular wave correcting circuit 112 for correcting waveform distortion of the intermittent triangular wave signal based on a differential voltage between a starting point and an ending point of the direct current interval of the intermittent triangular wave signal output from the integration circuit 12.

Abstract: A method and integrated circuit for the transmission of differential signals with a signal and a complementary signal is disclosed. For trimming the edge steepness of the signal with that of the complementary signal, the integrated circuit has a first driver for generating the signal, and a second driver for generating the complementary signal. A circuit is provided, configured to control the edge steepness of the signal or of the complementary signal.

Abstract: The present invention provides a ramp generator capable of appropriately setting a rise starting point of an output voltage of a ramp waveform and an output voltage at the time of stable output. A current adjustment unit including a differential pair of transistors and an amplifier constitute a feedback circuit. By controlling the charging/discharging of an integration capacitor by ON/OFF of a discharge current source connected to a common emitter terminal of the current adjustment unit, an output of the ramp waveform outputted from an output terminal disposed at the connection end of the integration capacitor is controlled.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: A dual differential sawtooth signal generator includes a first sawtooth voltage generator that has a first capacitor and a second capacitor that are alternately charged with a feedback control source current from a low voltage reference voltage level. A second sawtooth voltage generator has a first discharge capacitor and a second discharge capacitor that are alternately discharged with a feedback control sink current from a high voltage reference voltage level. The output signals of the two sawtooth voltage generators are compared to control a phase frequency comparator that provides signals to control a dual charge pump that provides the feedback control source current and that provides the feedback control sink current.

Abstract: An efficient ramp generator uses a reversing switch array to couple a timing capacitor in alternating polarities between an input terminal and an output terminal of an operational amplifier to generate a periodic ramp signal without discharging the timing capacitor between voltage ramps. The reversing switch array includes at least four semiconductor switches controlled by a flip-flop circuit or a latch circuit. The flip-flop circuit or the latch circuit can be driven by an external clock signal or an internal clock signal with a variable frequency.

Abstract: Zero crossings for a non-symmetrical VIN may be determined by first amplifying and clipping VIN to create a non-symmetrical square wave whose zero crossings are those of VIN. A selected polarity edge of the non-symmetrical square wave may be taken as a 0° indicator and is used to create a fundamental sawtooth ramp of the same frequency and in phase with VIN. The fundamental sawtooth ramp starts at zero volts, linearly ramps to some peak and is AC coupled to a comparator whose other input is zero volts. That creates a square wave that is symmetrical as to its half-cycles, and whose every other edge is synchronous with the start of the fundamental sawtooth ramp, and whose intervening edges occur in the middle of the ramp. The intervening edge is detected and taken as a 180° indicator.

Abstract: An oscillator circuit is disclosed that includes a first oscillation part configured to output a first oscillation output by charging and discharging a first capacitor, and a second oscillation part configured to output a second oscillation output by charging and discharging a second capacitor. The second oscillation part includes a phase difference detection part configured to detect the phase difference between the first oscillation output and the second oscillation output, and a charging current and discharge current control part configured to control the charging current and the discharge current of the second capacitor in accordance with the phase difference detected by the phase difference detection part so that the second oscillation output synchronizes with the first oscillation output.

Abstract: A ramp signal generation circuit is disclosed. The ramp signal generation circuit comprises a ramp signal generator, a buffer, a comparator, and a switching circuit. The switching circuit provides current to an output of the ramp signal generation circuit in response to a control signal output by the comparator. When a high slew rate is required, the output of the ramp signal generation circuit is driven by the current provided by the switching circuit. Otherwise, the output of the ramp signal generation circuit is driven by an output of the buffer.

Abstract: A pulse width modulation (PWM) amplifier which is capable of reducing unwanted radiation from a PWM output thereof, which can cause EMI, while reducing manufacturing costs thereof. A triangular wave-generating circuit (3) of the PWM amplifier outputs a triangular wave. The triangular wave has a waveform steep or gentle in pulse rising and falling slopes dependent on a value of current flowing through an FET (116) or an FET (117). The value of current is changed by a current flowing through a FET (112). A switching element (32) changes voltage applied to the gate of an FET (110), for control of increase and decrease in the current flowing through the FET (112). This enables the triangular wave to be generated such that it is formed by pulses having different periods. An input signal is subjected to PWM amplification based on the triangular wave generated.

Abstract: The integrating circuit of the triangular wave generating circuit includes an operational amplifier and a capacitor. Switch elements are alternatively turned ON and capacitors are alternatively recharged by the currents flowing in constant-current circuits thus obtaining a triangular wave on an output terminal. In this practice, when the voltage on the output terminal reaches ±1 V, comparator circuits (41, 42) and a flip-flop including NAND gates change over the switch elements. The currents flowing in the constant-current circuits are controlled depending on the current flowing in a load circuit. The current flowing in the load circuit is controlled by a PLL circuit including a phase comparator circuit, a loop filter, an LPF, an operational amplifier and an FET. This provides an output triangular wave having the same frequency as a clock pulse (CK).

Abstract: A generator circuit for voltage ramps is provided that includes a differential stage with positive feedback coupled between a first and a second voltage reference and having a first output connected to a control terminal of a first output transistor. The first output transistor is connected at an output terminal of the ramp generator circuit to a capacitive charge to be biased with voltage ramps. The ramp generator circuit also includes a second output transistor parallel connected to the first output transistor and having the control terminal connected to a second output of the differential stage.

Abstract: A stable, process independent RC time constant for precision frequency response in automatic tuning is generated using a feedback loop employing a voltage controlled resistor to force current through the output node to equal a reference current. The only terms in the expression for the time constant affected by process variations are two resistances, which are uniformly affected by any process variations to maintain proportion. The open loop transfer function for the feedback loop contains only one pole; because no phase-locked loop or other complex circuit introducing multiple poles within the feedback loop are employed, the time constant tuning filter is intrinsically stable.