Showing papers on "Static induction transistor published in 1968"

High voltage integrated circuit transistor

Abstract: TERING NORMAL COLLECTOR-EMITTER BREAKDOWN, BECAUSE THE FIELD INTENSITY IN THE COLLECTOR-BASE CHARGE LAYER IS LIMITED. AN INTEGRATED CIRCUIT TRANSISTOR INCLUDES A SUBSTRATE AND AN EPITAXIALLY GROWN SEMICONDUCTOR MATERIAL THEREON PROVIDING A THREE-LAYER TRANSISTOR COMPRISING A COLLECTOR LAYER, AN EMITTER LAYER, AND A BASE LAYER THEREBETWEEN. THE COLLECTOR LAYER IS CHARACTERIZED BY VIRTUALLY COMPLETE DEPLETION OF MAJORITY CARRIERS AT A COLLECTOR-EMITTER VOLTAGE LESS THAN THE VOLTAGE AT WHICH COLECTOR-EMITTER BREAKDOWN WOULD OTHERWISE OCCUR. AS A RESULT, THE COLLECTOR-EMITTER VOLTAGE MAY BE INCREASED WITHOUT ENCOUN-

Transistor switch with minimized transition power absorption

Abstract: A transistor switch, an inductor and the load are serially connected so that during turn-on transition of the transistor, the inductor holds back current flow until the transistor is saturated. A capacitor paralleled around the transistor charges during turnoff transition so that current through the transistor during transition is minimized to minimize power absorption therein.

Field-effect integrated circuit and method of fabrication

Abstract: An integrated circuit operating at about 77 DEG K. having first and second field effect transistors, a digital terminal being connected to the source of each transistor and capacitively coupled to the drain of the first transistor and the gate of the second transistor. A first read terminal is connected to the drain of the second transistor and capacitively coupled to the drain of the first transistor while a second read terminal is capacitively coupled to the drain of the first transistor. The method of fabrication makes use of stray capacitance in the laying of the layers.

Photodiode preamplifier circuit for a card reader system

Abstract: A photodiode preamplifier circuit including input terminals to which a photodiode may be connected. The photodiode senses the presence of a mark or a hole on a sense card and in turn provides a change in voltage at a control transistor to which the photodiode is connected. An output transistor is connected to the control transistor and is conductively controlled by the signal applied to the control transistor to in turn provide an output signal at one or the other of two binary levels. A reference level control means is connected between the control transistor and the input terminals of the amplifier and responds to current variations in the control transistor to produce a compensating current to the photodiode. This compensating current maintains a constant DC voltage level with reference to a constant threshold level at the output transistor.

Light measuring device

Abstract: A light measuring device includes a photoconductor and variable resistor series connected to a battery. The voltage across the variable resistor is applied to the input of a pair of amplifiers each of which includes an input switching transistor having emitter and collector resistors, and an output transistor with an output energizing a signal lamp. Another transistor has its input connected between the switching transistor collectors and its output to a third lamp. The ratio of the resistances of the collector and emitter resistors are different so that the switching transistor stages respond to different level signals and the output transistors are of opposite types.

Overvoltage and overcurrent protective circuit for a transistor amplifier

Abstract: A protective transistor connected in the input of a transistor amplifier is switched to its conductive condition when the difference between a voltage proportionate to the current flowing through the transistor amplifier and a voltage proportionate to the voltage applied to the transistor amplifier reaches a predetermined magnitude. When the protective transistor is switched to its conductive condition, it switches the transistor amplifier to its nonconductive condition.

Two-terminal monolithic voltage regulator and reach-through transistor

Abstract: A double diffused transistor structure having a base region which is sufficiently thin so that the reverse breakdown voltage between the emitter and the collector (BVeco) is less than the reverse breakdown voltage between the emitter and the base (BVebo). The transistor structure is connected in an upside-down fashion as a two-terminal network, the terminals being formed by the emitter and the collector in a manner similar to that heretofore employed with Zener diodes to provide a ''''reachthrough'''' at a predetermined voltage thereacross. A circuit utilizing such a ''''reach-through'''' transistor structure connected in the upside-down fashion in conjunction with other components to operate the transistor structure at a constant current to maintain the reverse breakdown voltage constant.

Temperature stabilization of transistor voltage regulators

Abstract: A transistor voltage regulator for regulating the output voltage of a generator. The generator is preferably a diode-rectified alternating current generator which is utilized to supply the electrical loads of a motor vehicle. The voltage regulator is of the switching-type and includes driver and output transistors connected such that when the driver transistor is nonconductive the output transistor is conductive and vice versa. The output transistor is connected with the field of the generator to control the output voltage of the diode-rectified alternating current generator. A thermistor, having a negative temperature coefficient of resistance is positioned to sense the temperature of the voltage regulator and is connected across the base and emitter electrodes of the output transistor. This thermistor provides stable operation of the voltage regulator at high temperatures by reducing the base drive to the base-emitter circuit of the output transistor when the driver transistor is biased fully conductive to ensure a nonconductive condition for the output transistor. In the preferred embodiment the driver transistor comprises two NPN-transistors connected in a Darlington configuration with the collectors of the transistors connected to the base of the output transistor through a forward biased PN-junction semiconductor diode.

Overheating protection circuit for a power transistor

Abstract: There is described an arrangement in which a power transistor chip is mounted on the end of a mounting stud together with a control transistor chip. The change in the base-to-emitter voltage drop of the control transistor chip with increase in temperature is used to operate a control circuit for turning off the power transistor with any overheating of the power transistor and associated mounting stud.

Transistor bias and temperature compensation circuit

Abstract: A NOVEL TRANSISTOR AMPLIFIER BIAS AND TEMPERATURE COMPENSATION CIRCUIT IS DISCLOSED EMPLOYING IN THE INPUT CIRCUIT A CURRENT-DIVISION NETWORK ONE PATH OF WHICH EMBODIES A DIODE OR THE LIKE CONNECTED BETWEEN THE BASE AND EMITTER OF THE AMPLIFIER.

Wide frequency range voltage controlled transistor relaxation oscillator

Abstract: A VOLTAGE CONTROLLED OSCILLATOR PROVIDING OUTPUT PULSES CONTROLLABLE IN FREQUENCY OVER A WIDE RANGE FROM A FEW HUNDREDTHS OF A HERTZ TO MEGAHERTZ WITH A HIGH DEGREE A ACCURACY AND STABILITY. THE OSCILLATOR EMPLOYS A TRANSISTOR CONSTANT CURRENT SOURCE FOR CHARGING AN ADJUSTABLE R-C TIMING CIRCUIT WHICH TRIGGERS A FEEDBACK CONTROLLED SWITCHING TRANSISTOR CIRCUIT. THE SWITCHING TRANSISTOR CIRCUIT ACTIVATES A SEPARATE TRANSISTOR DISCHARGE CIRCUIT WHICH ALSO SERVES FOR ISOLATING THE TRIGGERING INPUT FROM THE SWITCHING TRANSISTOR DURING SWITCHING TO ALLOW RAPID RESET OF THE TIMING CIRCUIT AND TO IMPROVE THE OUTPUT WAVEFORM.

Power transistor protection circuit

Abstract: A protection circuit is operatively connected to a power transistor in a power supply control circuit. Means are provided to derive signals representative of the current flow through the power transistor and to the voltage across that transistor, and to sum those signals. At excessive, unsafe current and voltage levels in the power transistor, that sum will exceed a predetermined value, and will be effective to decrease the current flowing through the power transistor.

High frequency power transistor having crossing input and output leads

Abstract: A HIGH FREQUENCY TRANSISTOR IS DESCRIBED HAVING INPUT, OUTPUT AND COMMON LEADS. IN ORDER TO REDUCE THE UNDESIRED FEEDBACK EFFECT OF A STRAY SERIES INDUCTANCE IN THE COMMON LEAD, THE OUTPUT LEADS ARE ARRANGED SO AS TO CROSS ONE ANOTHER IN SUCH CLOSE PROXIMITY AS TO INDUCTIVE- LY COUPLE THEM TOGETHER PROVIDING A FEEDBACK OPPOSITE TO THAT OF THE STRAY INDUCTANCE IN ORDER TO COMPENSATE THE LATTER.

Low voltage level mos interface circuit

Abstract: An input MOS device has its gate electrode connected to a network for biasing the gate slightly in excess of the threshold voltage for the device The excess bias is not greater than the maximum anticipated interface signal level which appears on the input electrode of the device A transistor is connected to the other electrode of the device for amplifying current from the device A second MOS device is connected in series with the transistor and a voltage source When the input voltage is equal to or less than the excess bias voltage, the input device turns on for driving the transistor and for connecting the output electrode of the second device to ground through the transistor When the input voltage is more than the excess bias voltage, the input device is turned off and the output electrode is driven to a usable MOS signal level

Power supply protector with reset means

Abstract: An electronic control protector system electrically positioned between a DC source and the regulator controls of a DC voltage regulator to reduce conduction of the regulator transistor when the current drawn to the load becomes excessive. The electronic control includes a bypass transistor maintained nonconducting in normal operation. Excess current flow, as indicated by a voltage drop across the load, causes the bypass transistor to conduct and reduce conduction of the regulator transistor. Reset means are provided to provide a short pulse to cut off the bypass transistor allowing normal operation of the regulator. If excess current is still flowing, the bypass transistor will again be rendered conducting to reduce conduction of the regulator transistor.

Fail-safe transistor gate circuit

Abstract: This disclosure relates to a fail-safe solid-state electronic logic circuit employing a pair of opposite conductivity types of transistor amplifiers. The transistor amplifiers are coupled in tandem and produce an AC output when and only when an AC input is present, the biasing voltage and ground connection of each amplifier is ''''true'''' and a critical circuit failure is absent.

Detection circuit including compensation for the threshold of the forward characteristic of a semiconductor junction

Abstract: A transistor detector circuit features a diode coupled in series with the base of the transistor to temperature compensate the circuit against temperature shifts in the base-emitter threshold voltage. A second transistor and a second diode can also be used for detecting signals of greater amplitude.

Color subcarrier oscillators

Abstract: A color subcarrier oscillator for a television receiver uses a transistor and a feedback network which serves to maintain oscillations in the transistor. The network is selected to provide a feedback signal of a magnitude sufficient to cause the transistor to cease conduction for a portion of a cycle at the frequency of oscillation and further serves to substantially eliminate transistor impedance variations from effecting the frequency of oscillation. In this manner the frequency is determined by a resonant circuit comprising a piezoelectric crystal and a variable reactance device. A transistor output stage operated in a class B mode receives both AC and DC bias from the collector electrode of the oscillator transistor. A high-Q tank in the collector of the class B stage converts current variations therein to sinusoidal voltage fluctuations which are monitored by a phase detector together with the color bursts to provide a control voltage used to synchronize the transistor oscillator via the variable reactance device.

Low-Noise l.f. amplification using a transistor chopper

Abstract: Reasons are given for the belief that the use of a transistor chopper, to make a low-frequency low-noise amplifier, should make possible the achievement of an exceptionally good noise performance. Two methods are proposed for gating out the noise produced by the chopper during switching edges.

Capacitor-transformer voltage equalization network for series connected transistor switches

Abstract: During the turnoff transition of series connected complementary transistor pair switches against a voltage in excess of the permissible standoff voltage of any one switch, it becomes necessary to equalize the voltage drop across each switch. Such equalization is accomplished by connecting a capacitor between the collector and base of each transistor in a complementary pair switch, with the capacitor having a larger displacement current than the collector current of that transistor. In this way, the rate of change of the collector to base voltage is maintained substantially equal between the several series connected transistors. This maintains substantially equal standoff voltage in each transistor during rise and fall times, providing transistor storage times are equal and turnoff signals are received at the same time. In order to overcome this potential cause of excessive voltage against any complementary pair transistor switch, pulse transformers are connected with one coil in series with the capacitor and the other coil in series with the emitter of the majority current carrying transistor so that the capacitive displacement current provides a voltage pulse in series aiding with the base-to-emitter voltage of the minority current carrying transistor to slow the transition speed of the succeeding complementary transistor pair switch first turning off and to allow its transition speed to approach that of the slower transition speed switch elements.