摘要:
An output MOS transistor and a current-detecting MOS transistor are connected commonly at their drains and gates. A gate voltage is fed to the gates of these transistors via signal lines. When the voltage of an output terminal is increased in response to excessive load current, a current-mirror circuit consisting of first and second transistors pulls in current from the signal line to reduce the gate voltage. Thus, the output current of output MOS transistor is limited within a predetermined level. Furthermore, a diode, provided in the signal line, produces a voltage drop equivalent to the base-emitter voltage of first transistor. By the function of this diode, the gate-source voltage of output MOS transistor is equalized with the gate-source voltage of current-detecting MOS transistor. As a result, the same operating point can be set for the output transistor and the current-detecting transistor.
摘要:
In a load actuation circuit of an emitter-follower circuit arrangement, a surge detection circuit detects a power surge voltage superposed on a power voltage of a power line. A feed circuit supplies current to a control electrode of an output transistor (i.e. emitter-follower transistor) from the power line to turn on the output transistor forcibly when any power surge voltage is detected by the surge detection circuit. Thus, the power surge voltage is absorbed by the output transistor.
摘要:
An input signal processing apparatus for use in a comparator which compares an input signal with a reference voltage signal to output a signal inverted in accordance with a comparison result. The apparatus detects the frequency of an input signal from a rotation detecting device such as pickup coil so that a mask time is set in accordance with the detected input signal frequency. The apparatus separates the levels of the input signal and a reference signal to the comparator for the mask time. The mask time is set so as to vary with a first predetermined rate of change when the input signal frequency is below a predetermined frequency and vary with a second predetermined rate of change greater than the first predetermined rate of change when the input signal frequency is above the predetermined frequency. This arrangement can appropriately set the mask time whereby it is possible to prevent the phase shift in waveshaping when the frequency of the input signal is high.
摘要:
An apparatus for driving a gauge having coils in quadrature to generate a resultant magnetic field in accordance with currents applied thereto and having a pointer angularly swept by the field, the apparatus having a memory to store a first data defining a relationship between a first level, indicative of the current applied to one of the coils, and an angle of the pointer. The first level has a continous waveform varying in isoceles trapezoid form over an angle range of 0.degree. to 180.degree.. The first data varies symmetrically with the isoceles trapezoid wave at the 180.degree. pointer angle over an angle range of 180.degree. to 360.degree.. The memory is arranged to store second data defining a relationship between a second level indicative of the current applied to the other coil and the pointer angle. The second level has a continuous waveform phase shifted by 90.degree. from the continuous waveform of the first data. The apparatus also has an output generator to generate output signals indicative of first and second levels related to the first and second data. A driving circuit is responsive to the output signals to drive the coils with currents proportional to the first and second levels. Each continuous waveform of the first and second data is modified so as to be cut triangularly at its corner portions.
摘要:
To improve reaction efficiency by increasing a contact area of first and second reactants per unit volume, without reducing dimensions of the inlet paths for the first and second reactants in a layer-thickness direction, a channel includes a first inlet path having the first reactant, a parallel second inlet path separated from the first inlet path and having the second reactant, a junction channel for causing the first and second reactants to join as separate laminar flows, and a parallel reaction channel connected with a downstream side of the junction channel for permitting the laminar flows of the first and second reactants to react at a contact interface thereof. A dimension of the reaction channel in the layer-thickness direction perpendicular to the contact interface is set to be smaller than the sum of the dimensions of the first inlet path and the second inlet path in the layer-thickness direction.
摘要:
A semiconductor device includes a semiconductor substrate, a first wire disposed on the semiconductor substrate, an first insulating layer disposed on the semiconductor substrate and the wire, a first thin film resistor having a first resistance within a predetermined error range, and a second thin film resistor having a second resistance which is allowable to be out of the predetermined error range. A surface of the first insulating layer includes a first area and a second area, in which the second area is located adjacent to the first wire. The first thin film resistor is disposed in the first area, and the second thin film resistor is disposed in the second area.
摘要:
An input protection circuit comprises a reverse flow preventing diode, a series circuit of a diode and a Zener diode, and a current path forming resistor or diode. The reverse flow preventing diode is connected between an input terminal and an internal circuit. The series circuit is connected between the input terminal and a ground. The current path forming resistor or diode is connected between a first common connection point of the reverse flow preventing diode and the internal circuit and a second common connection point of the series circuit, and sets a potential at the first common connection point to be less than a potential at the input terminal when the surge voltage is applied to the input terminal.
摘要:
A current mirror circuit includes transistors having bases coupled together and emitters connected to a voltage line. The current mirror circuit further includes a zener diode having an anode connected to the bases and a cathode connected to the voltage line. When a base potential of the transistors decreases, a reverse current of the zener diode increases. Therefore, the zener diode has a resistance and acts as a resistor to clamp the base potential of the transistors. A layout area of the zener diode is much smaller than that of the resistor having a resistance equal to that of the zener diode. The current mirror circuit achieves reduced chip size by using the zener diode instead of the resistor.
摘要:
In an operational amplifier, a differential amplifying circuit is configured to amplify an input voltage inputted from the input terminal. An outputting transistor is connected to the output terminal. A driving transistor is connected to the differential amplifying circuit and the outputting transistor. The driving transistor turns on according to a control signal supplied from the differential amplifying circuit to the driving circuit. The driving transistor is also configured to drive the outputting transistor according to the control signal. A control signal reducing circuit, when a voltage is applied on the driving transistor through the outputting transistor, is configured to reduce the control signal within a range that the driving transistor is kept to on state. The voltage applied on the driving transistor exceeds a predetermined threshold voltage.
摘要:
A semiconductor device includes an output power device, which generates an electrical noise, and an on-chip circuit, to which the noise is transmitted. The output power device is surrounded by two isolating regions. The area between the two isolating regions is electrically connected to a field ground area by a first wiring line. The field ground area is electrically connected to a point of contact, which has ground potential. The area between the outer isolating region of the two isolating regions and another isolating region around the on-chip circuit is also electrically connected to the field ground area by a second wiring line. The first and second wiring lines are separated from each other. The electrical noise is transmitted to the field ground area and released to the point of contact. Therefore, the noise is attenuated and the transmission of the noise to the on-chip circuit is suppressed.