LC87F7LC8A Datasheet, PDF (22/25 Pages) Sanyo Semicon Device – CMOS IC FROM 128K byte, RAM 4096 byte on-chip 8-bit 1-chip Microcontroller

LC87F7LC8A
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
SANYO-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
12MHz
MURATA
Oscillator Name
CSTCE12M0G52-R0
Circuit Constant
C1
C2
Rf1 Rd1
[pF] [pF]
[Ω]
[Ω]
(10) (10) Open 470
Operating
Voltage
Range
[V]
3.0 to 5.5
Oscillation
Stabilization Time
typ
max
[ms]
[ms]
0.05
0.15
Remarks
Internal
C1, C2
8MHz
MURATA
CSTCE8M00G52-R0
CSTLS8M00G53-B0
(10) (10) Open 2.2k
(15) (15) Open 680
2.7 to 5.5
2.5 to 5.5
0.05
0.05
0.15
Internal
0.15
C1, C2
4MHz
MURATA
CSTCR4M00G53-R0
CSTLS4M00G53-B0
(15) (15) Open 3.3k
(15) (15) Open 3.3k
2.2 to 5.5
2.2 to 5.5
0.05
0.15
Internal
0.05
0.15
C1, C2
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 Fig. 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 SANYO-
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]
[Ω]
[Ω]
[V]
[s]
[s]
32.768kHz SEIKO EPSON
MC-306
Applicable
18
18
Open 560k
2.2 to 5.5
1.4
3.0
CL value=12.5pF
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).
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
Rf1
C1
CF
CF2
Rd1
C2
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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