Integrated circuit for electronic timepieces

Claim 2

An integrated circuit chip adapted for association with the electromagnetic transducer of an electro-mechanical resonator to sustain the resonator in vibration at its natural frequency, said transducer having a drive and a phase-sensing coil, said chip being constituted by a super-gain transistor, a capacitor having a value in the picofarad range and a resistor in the megohm range, the input of said transistor being connectable through said capacitor to said phase-sensing coil and the output thereof being connectable through an external power source to said drive coil, said resistor being connected between said input and output of said transistor; said transistor, said capacitor and said resistor being fabricated to define monolithic structure.

Claim 3

An integrated circuit chip adapted for association with the electromagnetic transducer of an electro-mechanical resonator to sustain said resonator in vibration at its natural frequency, said transducer having a drive coil and a phase sensing coil, said chip comprising: A. a super-gain transistor having a base, an emitter and a collector, B. a resistor connected between said bAse and collector, C. means to connect said emitter and collector to said drive coil through an external power source whereby when said transistor is conductive, the resultant pulse actuates said resonator, D. a capacitor, E. means to connect said phase-sensing coil between said base and said emitter through said capacitor whereby the voltage induced in said phase-sensing coil by the vibrating resonator is applied between said base and emitter, and F. a resistor connected between said base and collector to produce base current, said capacitor having a small value in the picofarad range, said resistor having a large value in the megohm range which is sufficiently large to offset the small value of the capacitor, said transistor having a gain sufficiently great to offset the small base current resulting from the use of the large value resistor; said transistor, said capacitor and said resistor being fabricated to define a monolithic structure.

Claim 4

An integrated circuit chip adapted for association with the electromagnetic transducer of an electro-mechanical resonator to sustain said resonator in vibration at its natural frequency, said transducer having a drive coil and a phase sensing coil, said chip comprising: A. a super-gain transistor having a base, an emitter and a collector, B. a resistor connected between said bAse and collector, C. means to connect said emitter and collector to said drive coil through an external power source whereby when said transistor is conductive, the resultant pulse actuates said resonator, D. a capacitor, E. means to connect said phase-sensing coil between said base and said emitter through said capacitor whereby the voltage induced in said phase-sensing coil by the vibrating resonator is applied between said base and emitter, and F. a resistor connected between said base and collector to produce base current, said capacitor having a small value in the picofarad range, said resistor having a large value in the megohm range which is sufficiently large to offset the small value of the capacitor, said transistor having a gain sufficiently great to offset the small base current resulting from the use of the large value resistor; said transistor, said capacitor and said resistor being fabricated to define a monolithic structure.

Claim 5

An arrangement as set forth in claim 2, wherein said resonator is a tuning fork.

Claim 6

An arrangement as set forth in claim 3, wherein said tuning fork is provided with a permanent magnet on each tine, one cooperating with said drive coil and the other with said phase-sensing coil.

Claim 7

An arrangement as set forth in claim 2, wherein the value of said capacitor is less than 400 picofarads.

Claim 8

An arrangement as set forth in claim 2, wherein said resistor has a value in excess of 100 megohms.

Claim 9

An arrangement as set forth in claim 2, wherein said integrated circuit is formed on a chip having three terminals, one being connected to the emitter, the second to the collector and one end of said resistor, and the third to one end of the capacitor, the other end of said resistor and the other end of said capacitor being connected on said chip to said base.