UPD17708 datasheet(351/356 Pages) NEC

No. de pieza	UPD17708

Descripción Electrónicos	4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DEDICATED HARDWARE FOR DIGITAL TUNING SYSTEM

PDF	356 Pages

Scroll/Zoom	100%

Fabricante Electrónico	NEC [NEC]

Página de inicio	http://www.nec.com/

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351 / 356 page

351

µPD17704, 17705, 17707, 17708, 17709

APPENDIX A. CAUTIONS ON CONNECTING CRYSTAL RESONATOR

When using the system clock oscillation circuit, wire the portion enclosed by the dotted line in the figure below as

follows to prevent adverse influence from wiring capacity.

•

Keep the wiring length as short as possible.

•

If capacitances C1 and C2 are too high, the oscillation start characteristics may be degraded or current consumption

may increase.

•

Generally, connect a trimmer capacitor for adjusting the oscillation frequency to the XIN pin. Depending on the

crystal resonator to be used, however, the oscillation stability differs. Therefore, evaluate the crystal resonator

actually used.

•

The crystal oscillation frequency cannot be accurately adjusted when an emulation probe is connected to the

XOUT and XIN pin, because of the capacitance of the probe. Adjust the frequency while measuring the VCO

oscillation frequency.

PD17709

4.5-MHz crystal resonator

XOUT

XIN

UPD17708 Datasheet(PDF) 351 Page - NEC