The CF5019 series are high-frequency, 3rd overtone crystal oscillator module ICs. They incorporate an oscillator circuit and an output buffer that operate at high frequency on a single chip. The oscillator circuit employs CMOS inverters and a built-in damping resistor RD, reducing the crystal current compared with existing devices. The damping resistor RD is fabricated using NPC's unique high-precision thin-film resistor technology, which suppresses oscillator characteristic variations due to changes in temperature and voltage to a minimum. The CF5019 series can be utilized to construct stable, high-frequency, 3rd overtone crystal oscillators.