摘要:
A comparator with hysteresis in bipolar technology having a voltage/current converter with a voltage input forming the comparator input connection, and a current output, a bistable current source with a current feeding connection coupled with the current output of the voltage/current converter and a current output connection forming the comparator output, the bistable current source being currentless in a first stable state and consuming current only in the second stable state, the firing current which must be fed to the current feeding connection to switch the bistable current source from the currentless state to the power-consuming state being different from the quenching current which must be fed to the current feeding connection to switch the bistable current source from the power-consuming state to the currentless state, to obtain a hysteresis of the comparator, and all transistors being formed as bipolar transistors. The entire power consumption of such a comparator can be made extremely low in one of its two switching positions.
摘要:
A protection arrangement for a power semiconductor component made of a plurality of cells, in which a current sensor made of a current sense transistor and current sense resistors and also a temperature sensor, is disclosed. The current sense transistor and the temperature sensor are provided in a gap or in different gaps between the cells, while the current sense resistor is fitted directly on at least one cell. The temperature sensor may, include a plurality of stages which are located from the center of the power semiconductor component to an edge of the latter in the gap between two cells.
摘要:
A device for measuring a current flowing in an electrical conductor having a sensor disposed in the region of the electrical conductor for measuring the magnetic field surrounding the electrical conductor. The sensor includes a magnetic circuit having a first and a second section. A magnetizing device for the saturation of the second section and an evaluation device for calculating the current flowing through the electrical conductor in dependence on measured values B(P0), B(P1), B(P2), B(P4), B(P4+), B(P4−) of the magnetic field surrounding the electrical conductor and in dependence on the applicable magnetization of the second section is also provided. A method for operating the device is also disclosed.
摘要:
Driver and overload protection circuit for an electrical switch means. Switching control pulses with a minimum edge duration are fed to a two stage comparator circuit having first, lower and second, higher comparator threshold values. When the lower comparator threshold value is exceeded by a switching control pulse, the electrical switch means is rendered conducting. There is provided an overload detection circuit which, upon detection of overload of the electrical switch means, effects switching off of the same. For avoiding that turning on spikes upon each turning on of the electrical switch means, for example when switching capacitive loads, lead to deactivation of the switch means, any overload signal of the overload detector means is blocked as long as the instantaneous voltage value of the particular switching control pulse is not above the upper comparator threshold.
摘要:
A circuit configuration for a node of a bus system includes a transceiver circuit and a control circuit connected to the transceiver circuit. The transceiver circuit has an idle mode, in which it has a reduced power consumption in comparison with at least one operating mode, and the transceiver circuit is supplied with power in the at least one operating mode via a power supply unit integrated into the transceiver circuit. The control circuit is connected to the power supply unit to supply the control circuit with power in the idle mode, and the circuit configuration has a controllable voltage regulator which is coupled to the transceiver circuit in such a way that the voltage regulator is deactivated in the idle mode to reduce the power consumption and activated in the operating mode to supply power to the transceiver circuit and the control circuit.
摘要:
A reference voltage circuit has a reference voltage source, a charge storage device and also switching devices, which enable occasional operation of the reference voltage source during an on-time period. A reference voltage generated by the reference voltage source during the on-time period is stored in analog form with the charge storage device for the duration of an off-time period. The reference voltage source draws an operating current only during the on-time period. The result is a reduction of the power consumption. During the generation of the reference voltage, the operating current of the reference voltage source is not reduced compared with conventional reference voltage circuits.
摘要:
A driver circuit for slope-controlled pulsed switching of a load having a MOS switching transistor switching the load and a control loop with an amplifier having an amplifier input coupled with a switch control pulse source, an amplifier output connected with the gate of the MOS switching transistor, and a feedback capacitor. The driver circuit also includes a switchable current mirror circuit with a current mirror transistor formed by the MOS switching transistor and a diode transistor wired as a current mirror diode, a connection point between the diode transistor and the gate of the MOS switching transistor being connected with the amplifier output. A timer circuit is supplied on the input side with the switch control pulses from the switch control pulse source, and switches the diode transistor into a conductive state for essentially the duration of each switch control pulse edge and otherwise into a nonconductive state.
摘要:
A circuit configuration for a node of a bus system includes a transceiver circuit and a control circuit connected to the transceiver circuit. The transceiver circuit has an idle mode, in which it has a reduced power consumption in comparison with at least one operating mode, and the transceiver circuit is supplied with power in the at least one operating mode via a power supply unit integrated into the transceiver circuit. The control circuit is connected to the power supply unit to supply the control circuit with power in the idle mode, and the circuit configuration has a controllable voltage regulator which is coupled to the transceiver circuit in such a way that the voltage regulator is deactivated in the idle mode to reduce the power consumption and activated in the operating mode to supply power to the transceiver circuit and the control circuit.
摘要:
A method for limiting the frequency of a voltage-controlled oscillator in a control circuit of a resonant converter switched-mode power supply includes adjusting a delay time of a delay element disposed in a feedback branch of the voltage-controlled oscillator with a signal indicating a transition from negative to positive values of a current through an oscillating circuit of the switched-mode power supply. A resonant converter switched-mode power supply has an output voltage and an oscillating circuit with a current. A control circuit for the resonant converter switched-mode power supply includes a control amplifier being acted upon by the output voltage and by a reference voltage. A voltage-controlled oscillator is connected to and triggered by the control amplifier. A comparator detects a transition from positive to negative values of the current in the oscillating circuit. A flip-flop has a setting input being connected to and triggered by the voltage-controlled oscillator and has a reset input being connected to and triggered by the comparator. A delay element has a variable delay time and is triggered by a signal indicating a transition from negative to positive values of the current in the oscillating circuit.
摘要:
A switching regulator includes an inductive load. A monolithically integrated active free-running element includes an npn transistor switching the inductive load to generate a free-running current carried by the transistor. The transistor has a base terminal and collector and emitter terminals defining a collector-to-emitter voltage. A drive circuit has an output terminal connected to the base terminal of the transistor to trigger the transistor for operating the transistor largely into the saturation range, whenever the collector-to-emitter voltage of the transistor is positive.