461
CHAPTER 25 ELECTRICAL SPECIFICATIONS
User’s Manual U15798EJ2V0UD
Main system clock oscillator characteristics (T
A
=
−
40 to +85
°
C, V
DD
= 1.8 to 5.5 V)
Resonator
Recommended Circuit
Parameter
Conditions
MIN.
TYP.
MAX.
Unit
Ceramic
Oscillation
V
DD
= 1.8 to 5.5 V
2.0
10
MHz
resonator
frequency (f
X
)
Note 1
Oscillation
After V
DD
reaches oscil-
4
ms
stabilization time
Note 2
lation voltage range MIN.
Crystal
Oscillation
V
DD
= 1.8 to 5.5 V
2.0
10
MHz
resonator
frequency (f
X
)
Note 1
Oscillation
V
DD
= 1.8 to 5.5 V
10
ms
stabilization time
Note 2
External
X1 input
V
DD
= 4.5 to 5.5 V
2.0
10
MHz
clock
frequency (f
X
)
Note 1
V
DD
= 1.8 to 5.5 V
2.0
5.0
MHz
X1 input
V
DD
= 4.5 to 5.5 V
42.5
500
ns
high-/low-level width
V
DD
= 1.8 to 5.5 V
85
500
ns
(t
XH
, t
XL
)
Notes 1.
Indicates only oscillator characteristics.
2.
Time required to stabilize oscillation after reset or STOP mode release.
Cautions 1. When using the main system clock oscillator, wire as follows in the area enclosed by the
broken lines in the above figures to avoid an adverse effect from wiring capacitance.
•
Keep the wiring length as short as possible.
•
Do not cross the wiring with the other signal lines.
•
Do not route the wiring near a line through which a high fluctuating current flows.
•
Always make the ground point of the oscillator capacitor the same potential as V
SS1
.
•
Do not ground the capacitor to a ground pattern through which a high current flows.
•
Do not fetch signals from the oscillator.
2. When the main system clock is stopped and the system is operated by the subsystem clock,
the subsystem clock should be switched again to the main system clock after the oscillation
stabilization time is secured by the program.
Remark
For the resonator selection and oscillator constant, customers are requested to either evaluate the
oscillation themselves or apply to the resonator manufacturer for evaluation.
C1
X1
X2
V
SS1
C2
C1
X1
X2
V
SS1
C2
X1
X2
Содержание mPD780344 Series
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