MC72000 Freescale Semiconductor, MC72000 Datasheet - Page 47

• Manufacturer Part Number: MC72000
• Description: Integrated Bluetooth Radio
• Manufacturer: Freescale Semiconductor

For applications utilizing f
frequency is still usable. However, due to the R counter limitations, the R counter is programmed to
generate the f
frequencies above 20 MHz, R = 650
The N and R counters can only divide by integer values and the greatest common divider must be found to
represent f
For applications requiring a faster data clock PLL response time, refer to the data clock electrical
characteristics and An Improved PLL Design Method Application Note (document number AN1253/D)
Additional data clock characteristic data is shown in Figure 28 and Figure 29.
Where:
K
K
K
K
f
fo = Output frequency
fo/N = Feedback frequency divided by N
MOTOROLA
ref
pd
f
VCO
n
= Loop filter transfer function
Internal = Input Frequency
= Divide Ratio (1/N)
= Phase Detector Gain Constant
f
ref
Table 24. Data Clock R and N Counter Values for 20 kHz f
= VCO Gain Constant
f
(MHz)
External
19.22
19.68
19.88
ref
14.4
16.8
External
12
13
26
ref
Internal and achieve CLK. Table 24 provides the appropriate values for various f
ref
Internal to 40 kHz (recommended). In case of a 26 MHz external reference or other
÷R
ref
f
ref
Freescale Semiconductor, Inc.
Internal > 20 MHz, the external low pass filter with a 1.0 kHz corner
(kHz)
Internal
For More Information On This Product,
MC72000 Advance Information Data Sheet
20
20
20
20
20
20
20
40
Figure 27. General Model for the PLL
10
f
ref
Internal
and N = 600
Go to: www.freescale.com
Detector (K
Preliminary
R Counter
(Decimal)
Phase
10
600
650
720
840
961
984
994
650
.
pd
)
Divider
Filter
(K
(K
n
f
)
ref
N Counter
)
(Decimal)
Internal with 1.0 kHz LBW
1200
1200
1200
1200
1200
1200
1200
600
Radio Functional Description
(K
VCO
VCO
)
(kHz)
LBW
ref
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.4
Internal.
fo
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