UPD784031 Datasheet, PDF (60/90 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCONTROLLER

µPD784031
OSCILLATOR CHARACTERISTICS (TA = -40 to +85 °C, VDD = +2.7 to 5.5 V, VSS = 0 V)
Resonator
Ceramic resonator
or crystal
Recommended circuit
Parameter
Oscillator frequency (fXX)
MIN.
4
MAX.
16
VSS1 X1
X2
Unit
MHz
C1
C2
External clock
X1
X2
HCMOS
inverter
X1 input frequency (fX)
X1 input rise and fall times
(tXR, tXF)
X1 input high-level and low-
level widths (tWXH, tWXL)
4
16
MHz
0
10
ns
10
125
ns
Caution When using the system clock generator, run wires in the portion surrounded by broken lines
according to the following rules to avoid effects such as stray capacitance:
• Minimize the wiring.
• Never cause the wires to cross other signal lines.
• Never cause the wires to run near a line carrying a large varying current.
• Cause the grounding point of the capacitor of the oscillator circuit to have the same potential
as VSS1. Never connect the capacitor to a ground pattern carrying a large current.
• Never extract a signal from the oscillator.
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