Ic for crystal oscillator

Abstract

Abstract PURPOSE:To cope with a desired oscillation mode by one kind of IC through external operation by forming a resistance of an input terminal of an oscillation inverter so as to be switched selectively to a proper resistance to the fundamental wave oscillation of a crystal vibrator and the ternary overtone oscillation respectively. CONSTITUTION:A 1st resistor 31 is connected between an input terminal X and an output terminal, the inverse of X of an inverter 1 comprising a high speed CMOS element and a 2nd resistor 32 is connected between the input terminal X and a switching terminal 3/1. A crystal oscillation circuit of fundamental wave oscillation is constituted by means of the resistor 31 by connecting the crystal vibrator 2 and capacitors 4, 5 and in connecting the output terminal, the inverse X and a switching terminal 3/1 by using the switch 7 directly, the resistor 32 is connected between the input and output of the inverter 1 to constitute a ternary overtone oscillation circuit of the crystal vibrator 2. Thus, in operating the switching means 7, two kinds of desired oscillation modes are selected by one kind of IC.

Inventors

• 👤 Mikio Yamaguchi
• 👤 Yoshio Arai

Bibliographic Details