DATA SHEET
MSP 34x0G
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
PMQFP 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 value should be determined with the customer PCB. The suggested values (1.5...3.3 pF) are
figures based on experience and should serve as “start value”.
To adjust the capacitor value, reset the MSP. After the reset, no I2C telegrams should be transmitted. Measure
the frequency at AUD_CL_OUT-pin. Change the capacitor value until the free running frequency matches
18.432 MHz as closely as possible. The higher the capacity, the lower the resulting clock frequency.
Note: To minimize adjustment tolerances for all MSP-generations, it is strongly recommended to use the so-
called MSP-XTAL-REF ICs (available in all packages) for the capacitor adjustment.
Micronas
May 27, 2003; 6251-476-1DS
67
MICRONAS [ MICRONAS ]
