UPD75P0076 Datasheet, PDF (35/62 Pages) NEC – 4-BIT SINGLE-CHIP MICROCONTROLLER

µPD75P0076
SUBSYSTEM CLOCK OSCILLATOR CHARACTERISTICS (TA = –40 to +85˚C, VDD = 1.8 to 5.5 V)
Resonator Recommended constant
Parameter
Test conditions
MIN. TYP. MAX. Unit
Crystal
resonator
XT1
XT2
Oscillation
R
frequency (fXT)^{Note 1}
32 32.768 35 kHz
C3
C4 Oscillation
VDD = 4.5 to 5.5 V
1.0 2
s
stabilization time^{Note 2}
10
External
clock
XT1
XT2
XT1 input frequency
(fXT)^{Note 1}
32
100 kHz
XT1 input high-/low-level
5
15 µs
width (tXTH, tXTL)
Notes 1. Indicates only oscillator characteristics. Refer to AC Characteristics for instruction execution time.
2. The oscillation stabilization time is necessary for oscillation to stabilize after applying VDD.
Caution When using the subsystem clock oscillator, wiring in the area enclosed with the dotted line should
be carried out as follows to avoid an adverse effect from wiring capacitance.
• Wiring should be as short as possible.
• Wiring should not cross other signal lines.
• Wiring should not be placed close to a varying high current.
• The potential of the oscillator capacitor ground should be the same as VSS.
• Do not ground it to the ground pattern in which a high current flows.
• Do not fetch a signal from the oscillator.
The subsystem clock oscillator is designed as a low amplification circuit to provide low consumption
current, causing misoperation by noise more frequently than the main system clock oscillation
circuit. Special care should therefore be taken for wiring method when the subsystem clock is used.
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