LC87F0808AUQFPTLM-H Datasheet, PDF (21/25 Pages) ON Semiconductor – 8-bit 1-chip Microcontroller

LC87F0808A
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
MURATA
Nominal
Frequency
Type
Oscillator Name
Circuit Constant
C1
C2
Rf
Rd
[pF] [pF]
[Ω]
[Ω]
Operating
Voltage Range
[V]
Oscillation
Stabilization Time
typ
max
[ms]
[ms]
Remarks
SMD
CSTCE20M0G51-R0
(5)
(5) Open 470
3.3 to 5.5
0.02
20MHz
LEAD
CSTLS20M0G52-B0
(5)
(5) Open 330
3.3 to 5.5
0.06
SMD
CSTCE10M0G52-R0
(10) (10) Open 470
3.3 to 5.5
0.02
10MHz
LEAD
CSTLS10M0G53-B0
(15) (15) Open 680
3.3 to 5.5
0.02
Internal
C1,C2
SMD
CSTCR4M00G53-R0
(15) (15) Open 1.5k
3.3 to 5.5
0.04
4MHz
LEAD
CSTLS4M00G53-B0
(15) (15) Open 1.5k
3.3 to 5.5
0.03
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 3).
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 Oscillator Circuit with a Crystal Oscillator
EPSON TOYOCOM
Nominal
Frequency
Type
Oscillator
Name
Circuit Constant
C1
C2
Rf
[pF]
[pF]
[Ω]
Oscillation
Operating
Stabilization Time
Voltage Range
Rd
typ
max
[V]
[Ω]
[s]
[s]
Remarks
Applicable
32.768kHz
SMD
MC-306
8
8
Open 330k
3.3 to 5.5
1.0
4.0
CL value =
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 Figure 3).
Note: 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/XT1
CF2/XT2
Rf
Rd
C1
CF/X’tal
C2
Figure 1 CF and XT Oscillator Circuit
0.5VDD
Figure 2 AC Timing Measurement Point
No.A1828-21/25