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CHAPTER 31 ELECTRICAL SPECIFICATIONS ((A2) GRADE PRODUCTS)
User’s Manual U16228EJ2V0UD
509
Ring-OSC Oscillator Characteristics
(T
A
=
40 to +125
°
C, 3.3 V
≤
V
DD
= EV
DD
≤
5.5 V, 3.3 V
≤
AV
REF
≤
V
DD
, V
SS
= EV
SS
= AV
SS
= 0 V)
Resonator
Parameter
Conditions
MIN.
TYP.
MAX.
Unit
On-chip Ring-OSC oscillator
Oscillation frequency (f
R
)
120
240
495
kHz
Subsystem Clock Oscillator Characteristics
(T
A
=
40 to +125
°
C, 3.3 V
≤
V
DD
= EV
DD
≤
5.5 V, 3.3 V
≤
AV
REF
≤
V
DD
, V
SS
= EV
SS
= AV
SS
= 0 V)
Resonator
Recommended Circuit
Parameter
Conditions
MIN.
TYP.
MAX.
Unit
Crystal
resonator
XT1
V
SS
XT2
C4
C3
Rd
Oscillation frequency
(f
XT
)
Note
32
32.768
35
kHz
XT1 input frequency
(f
XT
)
Note
32
38.5
kHz
External clock
XT1
XT2
XT1 input high-/low-level
width (t
XTH
, t
XTL
)
12
15
μ
s
Note
Indicates only oscillator characteristics. Refer to
AC Characteristics
for instruction execution time.
Cautions 1. When using the subsystem 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 signal line through which a high fluctuating current flows.
Always make the ground point of the oscillator capacitor the same potential as V
SS
.
Do not ground the capacitor to a ground pattern through which a high current flows.
Do not fetch signals from the oscillator.
2. The subsystem clock oscillator is designed as a low-amplitude circuit for reducing power
consumption, and is more prone to malfunction due to noise than the X1 oscillator. Particular
care is therefore required with the wiring method when the subsystem clock is used.
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.