| 摘要 |
PURPOSE:To obtain an oscillation circuit which has a small number of external elements and is affected less by external circuits by setting the input capacities of the 2nd and the 3rd transistor (TR) to an enough value to oscillate the circuit composed of the 1st and the 2nd TRs and an oscillation element. CONSTITUTION:Positive feedback to the base of a TR 2 is provided by the composite capacity of the collector-base mirror capacity and base-emitter capacity of a TR 7, the base-emitter capacity of a TR 3, and a crystal oscillating element to cause oscillation, whose oscillation output is inputted to the base of the TR 7 from the emitter of the TR 2, so that the oscillation output is led out of the collector of the TR 7. A positive feedback circuit which utilizes the mirror capacity and base-emitter capacity of the TRs 3 and 7 for the TR 2 constituting an oscillator is constituted to decrease the number of external elements of a semiconductor integrated circuit, and an output is led out of the collector of the TR 7 to reduce the influence of a trailing stage circuit.
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