MB88155 Fujitsu Media Devices, MB88155 Datasheet - Page 19

• Manufacturer Part Number: MB88155
• Description: Spread Spectrum Clock Generator
• Manufacturer: Fujitsu Media Devices

OSCILLATION CIRCUIT
The following schematic on the left-hand side shows a sample connection of a general resonator. The oscillation
circuit contains a feedback resistor (1 MΩ) . The values of capacitors (C
constant of the resonator used.
The following schematic on the right-hand side shows a sample connection of a 3rd overtone resonator. The
values of capacitors (C
used.
The most suitable value is different by individual resonator. Please refer to the resonator manufacturer which
you use for the most suitable value.
To use an external clock signal (without using the resonator) , input the clock signal to the XIN pin with the XOUT
pin connected to nothing .
• When using the resonator
• When using the external clock
Note :
XIN pin
C
1
Note that the jitter characteristic of the input clock signal may affect the cycle-cycle jitter
characteristic.
Fundamental resonator
R
1
f
, C
(1 MΩ)
2
, and C
XIN pin
C
3
2
) and inductor (L
XOUT pin
External clock
LSI external
LSI internal
R
f
(1 MΩ)
1
) must be adjusted to the optimum constant of the resonator
XIN pin
C
OPEN
1
LSI internal
LSI external
XOUT pin
3rd overtone resonator
1
and C
R
f
(1 MΩ)
2
) must be adjusted to the optimum
C
2
MB88155
XOUT pin
C
L
1
3
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