PRELIMINARY DATA SHEET
MSP 44x8G
4.6.2.4. Crystal Recommendations
Symbol
Parameter
Pin Name
Min.
Typ.
Max.
Unit
General Crystal Recommendations
fP
Crystal Parallel Resonance Fre-
18.432
MHz
quency at 12 pF Load Capacitance
RR
C0
CL
Crystal Series Resistance
8
25
Ω
Crystal Shunt (Parallel) Capacitance
External Load Capacitance1)
6.2
7.0
pF
XTAL_IN,
XTAL_OUT
PSDIP approx. 1.5
P(L)QFP approx. 3.3
pF
pF
Crystal Recommendations for Master-Slave Applications (MSP-clock must perform synchronization to I2S clock)
fTOL
Accuracy of Adjustment
−20
−20
+20
+20
ppm
ppm
DTEM
Frequency Variation
versus Temperature
C1
Motional (Dynamic) Capacitance
19
24
fF
AUD_CL_OUT
fCL
Required Open Loop Clock
18.431
18.433 MHz
Frequency (Tamb = 25 °C)
Crystal Recommendations for FM / NICAM Applications (No MSP-clock synchronization to I2S clock possible)
fTOL
Accuracy of Adjustment
−30
−30
+30
+30
ppm
ppm
DTEM
Frequency Variation
versus Temperature
C1
Motional (Dynamic) Capacitance
15
fF
18.4305
18.4335
fCL
Required Open Loop Clock
AUD_CL_OUT
MHz
Frequency (Tamb = 25 °C)
Crystal Recommendations for all analog FM/AM Applications (No MSP-clock synchronization to I2S clock possible)
fTOL
Accuracy of Adjustment
−100
−50
+100
+50
ppm
ppm
DTEM
Frequency Variation
versus Temperature
fCL
Required Open Loop Clock
AUD_CL_OUT
18.429
18.435 MHz
Frequency (Tamb = 25 °C)
Amplitude Recommendation for Operation with External Clock Input (Cload after reset typ. 22 pF)
VXCA
External Clock Amplitude
XTAL_IN
0.7
Vpp
1)
External capacitors at each crystal pin to ground are required. They are necessary to tune the open-loop fre-
quency of the internal PLL and to stabilize the frequency in closed-loop operation.
Due to different layouts, the accurate capacitor size should be determined with the customer PCB. The sug-
gested values (1.5...3.3 pF) are figures based on experience and should serve as “start value”.
To define the capacitor size, reset the MSP without transmitting any further I2C telegrams. Measure the fre-
quency at AUD_CL_OUT-pin. Change the capacitor size until the free running frequency matches 18.432 MHz
as closely as possible. The higher the capacity, the lower the resulting clock frequency.
Micronas
53
MICRONAS [ MICRONAS ]
