LC87F2C64A Datasheet, PDF (24/28 Pages) Sanyo Semicon Device – 8-bit 1-chip Microcontroller

LC87F2C64A
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.
Table1. Characteristics of a Sample Main System Clock Oscillator Circuit with a Ceramic Oscillator
Nominal
Frequency
Vendor Name
Oscillator Name
Circuit Constant
C1 C2
Rf
Rd
Operating
Voltage
Range
Oscillation
Stabilization Time
typ
max
[pF] [pF] [Ω]
[Ω]
[V]
[ms]
[ms]
Remarks
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 SANYO-
designated oscillation characteristics evaluation board and external components with circuit constant values with
which the oscillator vendor confirmed normal and stable oscillation.
Table2. Characteristics of a Sample Subsystem Clock Oscillator Circuit with a Crystal Oscillator
Nominal
Frequency
Vendor Name
Oscillator
Name
Circuit Constant
C1
C2
Rf
Rd
[pF] [pF] [Ω]
[Ω]
Operating
Voltage
Range
[V]
Oscillation
Stabilization Time
typ
max
[s]
[s]
Remarks
32.768kHz
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 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
C1
Rf1
CF
CF2
Rd1
C2
Figure 1 Ceramic Oscillation Circuit
XT1
XT2
Rf2
Rd2
C3
C4
X’tal
Figure 2 Crystal Oscillation Circuit
0.5VDD
Figure 3 AC Timing Measurement Point
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