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ST92F124/F150/F250 - RESET AND CLOCK CONTROL UNIT (RCCU)
CERAMIC RESONATORS
Murata Electronics CERALOCK resonators have been tested with the ST92F150 at 3, 3.68, 4 and 5 MHz.
These recommended resonators have built-in capacitors (see
Table 32
).
The test circuit is shown in
Figure 69
.
Figure 69. Test Circuit
Table 32
shows the recommended conditions at different frequencies.
Table 32. Obtained Results
Advantages of using ceramic resonators:
CSTCR and CSTCC types have built-in loading
capacitors.
Smallest loading capacitor resonators are recom-
mended for standard applications.
Highest loading capacitor resonators are recom-
mended for automotive applications with CAN and
tight frequency tolerance.
Test conditions:
The evaluation conditions are 4.5 to 5.5 V for the
supply voltage and -40° to 105° C for the tempera-
ture range.
Caution:
These circuit conditions are for design reference
only.
Recommended C1, C2 value depends on the cir-
cuit board used.
For tight frequency tolerance applications, please
contact the nearest Murata office for more de-
tailled PCB evaluation regarding layout.
Note 1:
Attention must be paid to leakage currents around
the OSCIN pin. Leakage paths from V
DD
could al-
ter the DC polarization of the inverter stage and in-
troduce a mismatch with the second stage, and
possibly stop the clock signal. It is recommended
to surround the oscillator components by a ground
ring on the printed circuit board and if necessary to
apply a coating film to avoid humidity problems.
Note 2:
Attention must be paid to the capacitive loading of
OSCOUT. OSCOUT must not be used to drive ex-
ternal circuits.
V
DD
OSCIN
C1
C2
CERALOCK
ST92F150
Rd
OSCOUT
V
SS
Freq.
(MHz)
Parts Number
C1 (pF)
C2 (pF)
Rd (Ohm)
5
CSTCR5M00G55A-R0
CSTCC5M00G56A-R0
CSTCR4M00G55A-R0
CSTCC4M00G56A-R0
CSTCC3M00G56A-R0
CSTCC3M68G56A-R0
39
47
39
47
47
47
39
47
39
47
47
47
0
0
0
0
0
0
4
3
3.68
9