Abstract: A biasing circuit (30) for an output vertical pnp transistor (10) formed in an integrated circuit and having an outer epitaxial region (20) includes a biasing vertical pnp transistor (33) and a comparator (38). Biasing circuit (30) is electrically connected to the integrated circuit voltage supply and the outer epitaxial region (20) of the output vertical pnp transistor (10) for electrically connecting the outer epitaxial region (20) to the voltage supply when the voltage at an output terminal (23) does not exceed the supply voltage and electrically disconnecting the outer epitaxial region (20) from the voltage supply when the voltage at the output terminal (23) exceeds the supply voltage, whereby improper operation of and damage to the integrated circuit upon the occurrence of an external fault condition is at least minimized.

Abstract: A protective circuit having enhanced and accurate thermal shutdown temperatures. The protective circuit establishes the thermal shutdown temperature within a predetermined range and provides an output signal when the thermal shutdown temperature is exceeded. The protective circuit, in one embodiment, comprises a current generator for supplying a predetermined collector current I.sub.c1, a current mirror arrangement for supplying a collector current I.sub.c2 which has a mirror response to that of the collector current I.sub.c1, a resistor arranged to have the mirror collector current I.sub.c2 flowing therethrough, and the combination of a resistor and a bipolar transistor serving as a thermal sensor. The current generator comprises at least a pair of bipolar transistors selected from one of the NPN and PNP types with each of said pair operating with different current densities. The base electrodes of the pair are interconnected by a resistor. The collector current I.sub.

Abstract: A circuit and method are provided for generating a clipping distortion detector output signal for an integrated circuit audio amplifier which is independent of operating temperature and supply voltage. The system includes an audio amplifier having a voltage gain, a first input for receiving input voltage and an output for generating an amplified output voltage. A supply voltage is supplied to the audio amplifier and the supply voltage determines the maximum amplified output voltage. A comparison voltage is generated which is indicative of the output voltage divided by the voltage gain. A clip detector voltage comparator receives the input voltage and the comparison voltage and provides a clipping distortion detect signal when the input voltage deviates from the comparison voltage in excess of an offset voltage which is indicative of detection of excessive clipping distortion.

Abstract: A supplemental inflatable restraint deployment system comprises an energy reserve capacitor, a first supplemental inflatable restraint deployment circuit comprising a controllable current source in series with a first squib, a second supplemental inflatable restraint circuit comprising a second controllable current source in series with a second deployment squib and a control unit for providing a first pulse of first duration to the first controllable current source to activate the first squib and for providing a second pulse of second predetermined duration to the second controllable current source to activate the second squib, wherein the first and second pulses are staggered with respect to each other.

Abstract: A circuit and method are provided for generating a clipping distortion detector output signal for an integrated circuit audio amplifier which is independent of operating temperature and supply voltage. The system includes an audio amplifier having a voltage gain, a first input for receiving an input voltage and an output for generating an amplified output voltage. A supply voltage is supplied to the audio amplifier and the supply voltage determines the maximum amplified output voltage. A comparison voltage is generated which is indicative of the output voltage divided by the voltage gain. A clip detector voltage comparator receives the input voltage and the comparison voltage and provides a clipping distortion detect signal when the input voltage deviates from the comparison voltage in excess of an offset voltage which is indicative of detection of excessive clipping distortion.

Abstract: A circuit limits the output drive current from an interface drive circuit comprising drive transistors. The circuit makes dual use of an external series supply resistor as a current sensing element. The increased voltage drop across the external resistor due to excessive current draw through the drive transistors is coupled to a control transistor, which reduces base drive current to the drive transistors in response to the increased voltage drop.

Abstract: An ignition system for a spark-ignited internal combustion engine has a transistor connected in series with the primary winding of an ignition coil. The transistor is switched ON and OFF in synchronism with rotation of the crankshaft of the engine. Primary winding current is sensed by a resistor and the voltage developed across the resistor is fed back into an error amplifier which causes the transistor to be biased into a current-limiting mode when primary winding current increases to a predetermined level. The feedback loop has a capacitor which is a feedback compensation element. This capacitor, together with a resistor form an RC timing circuit which is operative at times to prevent the transistor from being biased back ON for a predetermined time period after it has been biased OFF.

Abstract: An input buffer apparatus receives data from a single ended transmission line and provides an output signal in one or two states in response to the state of the signal on the input. The apparatus has hysteresis with temperature stable upper and lower thresholds. Temperature stability is achieved by providing first and second temperature dependent reference currents, one with a positive temperature coefficient and one with a negative temperature coefficient and by adjusting the temperature coefficients of the first and second reference currents so that the sum effect of all of the temperature coefficients of the system is substantially zero.

Abstract: A conventional PNP transistor current mirror provides identical first and second reference currents each containing the same noise component (which may be due to high frequency supply voltage variations). An input current is subtracted from the first reference current to provide a difference current containing the noise component in the first reference current. An NPN current mirror subtracts the difference current from the second reference current such that the noise component in the difference current cancels the noise component in the second reference current to provide an output current which is an identical "mirror image" of the input current and which is free of the cancelled noise component.