Logic operation-oscillation circuit

An "AND" logic operation-oscillation circuit which comprises:

• a pair of power supply terminals, a first of which is receptive of a reference voltage and a second of which is receptive of a power source voltage,
• a plurality of input terminals for input signal each having a voltage higher than the power source voltage,
• a first transistor for generating an oscillation output, said first transistor having a collector connected with one of said input terminals and an emitter connected with one of said power supply terminals,
• first and second resistive means connected in series between said first input terminal and said collector of said first transistor,
• a second transistor having a collector connected with another of said input terminals, a base connected to a voltage corresponding to a voltage between said first and second resistive means and an emitter connected with said second power supply terminal,
• a third resistive means connected between said another input terminal and said collector of said second transistor,
• fourth and fifth resistive means connected in series between said collector of the second transistor and said first power supply terminal,
• a third transistor of a complementary structure to said second transistor, which has an emitter connected with said second power supply terminal, a collector connected to said first power supply terminal and a base connected to a voltage between said fourth and fifth resistive means,
• and sixth and seventh resistive means connected in series between said collector of the third transistor and said first power supply terminal, a voltage between said sixth and seventh resistive means being supplied to a base of said first transistor,
• said circuit being so constituted that said first and third resistive means are non-diffused resistive means and other resistive means, to which a voltage no greater than the power source level is supplied, are diffused resistive means, and
• a conductor positioned between mutually adjoining non-diffused resistive means and kept at a voltage level below the threshold level for generating oscillation output at said first transistor.

In an oscillating circuit connected for oscillation when input voltages to at least two input terminals thereof are both at voltage levels higher than a level of a power supply voltage thereof, the oscillating circuit including input resistors connected to said input terminals and a plurality of interconnected circuit resistors and transistors, the oscillating circuit including means operable during oscillation thereof for connecting the circuit resistors to voltage levels lower than the power supply voltage and the input resistors to voltage levels higher than the power supply voltage thereof, the improvement comprising:

• a circuit structure for said oscillating circuit wherein said input resistors comprise non-diffused resistors connected to the input terminals, and
• said circuit resistors comprise a plurality of diffused resistors provided in said oscillating circuit, and
• a conductor means connected to a voltage level lower than a threshold voltage level necessary on said input terminals for initiating oscillation of said oscillating circuit,
• wherein said conductor means is disposed between said non-diffused resistors, thereby separating said non-diffused resistors by a voltage level insufficient to initiate oscillation,
• whereby oscillation of said oscillating circuit due to short-circuit between said non-diffused resistors is prevented,
• said oscillating circuit means thereby providing said voltage levels higher than the power supply voltage only to said non-diffused resistors and said voltage levels lower than the power supply voltage to said diffused resistors.