MC72000 Freescale Semiconductor, MC72000 Datasheet - Page 35

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

Figure 10. Receive Sensitivity vs. Temperature
6.3.5 Demodulator
The receiver in the MC72000 down converts the RF signal and demodulates it. The demodulator takes the
IF signal from the limiter and delivers a baseband signal to an A/D converter (ADC). The 6-bit ADC uses
the Redundant Sign Digit (RSD) Cyclic architecture that samples the analog input at 4.0 Msamples/s. The
resulting demodulated data out of the MC72000 is a 24 Mbit/s, 2’s-complement serial bit stream. The start
of each 6-bit data stream is indicated by a frame sync (FS) signal internal to the baseband processor. A
24 MHz clock output accompanies the demodulated data.
6.3.5.1 Receiver Characteristics
For optimum intermodulation and C/I performance, the MC72000 GND_RF pins require good conduction
to the PCB ground layer. Figure 10 through Figure 16 show typical performance of the receiver for various
conditions.
MOTOROLA
Figure 8. RF Level vs. RSSI at Temperature
-40
-45
-50
-55
-60
-65
-70
-75
1.0
3.0
T
-20°C
A
= 85°C
5.0
RSSI CONVERSION VALUE
TBD
7.0
55°C
0°C
25°C
Freescale Semiconductor, Inc.
9.0
For More Information On This Product,
MC72000 Advance Information Data Sheet
11
-40°C
Go to: www.freescale.com
13
Preliminary
15
Figure 11. Blocking Performance vs. Continuous
-40
-45
-50
-55
-60
-65
-70
-75
-10
-20
-30
-40
-50
40
30
20
10
0
1.0
Figure 9. RF Level vs. RSSI at V
3.1 V
CONTINUOUS WAVE INTERFERING SIGNAL FREQUENCY (GHz)
3.0
2.5 and 2.7 V
Wave Interfering Signal
T
A
5.0
Radio Functional Description
RSSI CONVERSION VALUE
= 25° C
7.0
9.0
T
A
= 25°C
11
CC
RF
13
35
15