LC87F7NC8A Datasheet, PDF (25/28 Pages) ON Semiconductor – 8-bit Microcontroller

LC87F7NC8A
Characteristics of a Sample Main System Clock Oscillation Circuit
Given below are the characteristics of a sample main system clock oscillation circuit that are measured using a Our
designated oscillation characteristics evaluation board and external components with circuit constant values with
which the oscillator vendor confirmed normal and stable oscillation.
Table 1 Characteristics of a Sample Main System Clock Oscillator Circuit with a Ceramic Oscillator
Nominal
Frequency
Vendor
Name
Oscillator Name
Oscillation
Operating
Circuit Constant
Stabilization
Voltage
Time
Range
C1
C2
Rf1
Rd1
typ max
[V]
[pF] [pF]
[]
[]
[ms] [ms]
Remarks
CSTCE18M0V51-R0
(5)
(5) OPEN 150 2.7 to 3.6 0.05 0.15 ^{Values shown in parentheses}
18MHz MURATA
are capacitance included
CSTLS18M0X51-B0
(5)
(5) OPEN
0
2.7 to 3.6 0.11 0.33
in the oscillator
CSTCE10M00G52-R0 (10)
10MHz MURATA
CSTLS10M00G53-B0 (15)
(10) OPEN 680 2.5 to 3.6 0.05 0.15 ^{Values shown in parentheses}
are capacitance included
(15) OPEN 1.5k 2.5 to 3.6 0.05 0.15
in the oscillator
CSTCE8M00G52-R0
(10)
(10) OPEN 680 2.5 to 3.6 0.05 0.15 ^{Values shown in parentheses}
8MHz
MURATA
are capacitance included
CSTLS8M00G53-B0
(15) (15) OPEN 1.5k 2.5 to 3.6 0.05 0.15
in the oscillator
The oscillation stabilization time refers to the time interval that is required for the oscillation to get stabilized after VDD
goes above the operating voltage lower limit (see Figure 4).
Characteristics of a Sample Subsystem Clock Oscillator Circuit
Given below are the characteristics of a sample subsystem clock oscillation circuit that are measured using a Our
designated oscillation characteristics evaluation board and external components with circuit constant values with
which the oscillator vendor confirmed normal and stable oscillation.
Table 2 Characteristics of a Sample Subsystem Clock Oscillation Circuit with a Crystal Oscillation
Nominal
Frequency
Vendor Name
Oscillator
Name
Circuit Constant
Operating
Voltage
Oscillation
Stabilization Time
C3
C4
Rf2
Rd2
Range
typ
max
Remarks
[pF]
[pF]
[]
[]
[V]
[s]
[s]
32.768kHz
EPSON
TOYOCOM
MC-306
9
9
Open 330k
2.5 to 3.6
1.0
3.0
CL=7.0pF
The oscillation stabilization time refers to the time interval that is required for the oscillation to get stabilized after the
instruction for starting the subclock oscillation circuit is executed and to the time interval that is required for the
oscillation to get stabilized after the HOLD mode is reset (see Fig. 4).
Caution: The components that are involved in oscillation should be placed as close to the IC and to one another as
possible because they are vulnerable to the influences of the circuit pattern.
CF1
CF2
Rf1
Rd1
C1
C2
CF
Figure 1 CF Oscillator Circuit
XT1
XT2
Rf2
Rd2
C3
C4
X’tal
Figure 2 XT Oscillator Circuit
0.5VDD
Figure 3 AC Timing Measurement Point
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