Micrel, Inc.
MICRF002/RF022
for the vast majority of applications. If adjustment is
required the constant may be varied by adding a resistor in
parallel with the CAGC capacitor. The value of the resistor
must be determined on a case by case basis.
0.65
(8)
Demoulator bandwidth =
Shortest pulse − width
It should be noted that the values indicated in Table 1 are
nominal values. The filter bandwidth scales linearly with
frequency so the exact value will depend on the operating
frequency. Refer to the “Electrical Characteristics” for the
exact filter bandwidth at a chosen frequency.
Step 5: Selecting The Demod Filter Bandwidth
The inputs SEL0 and SEL1 control the demodulator filter
bandwidth in four binary steps (625Hz to 5000Hz in sweep,
1250Hz to 10000Hz in fixed-mode), see Table 3.
Bandwidth must be selected according to the application.
The demodulator bandwidth should be set according to
Equation 8:
Demodulator Bandwidth
SEL0
SEL1
Sweep-Mode
5000Hz
Fixed-Mode
10000Hz
5000Hz
1
0
1
0
1
1
0
0
2500Hz
1250Hz
2500Hz
625Hz
1250Hz
Table 1. Nominal Demodulator Filter Bandwidth vs.
SEL0, SEL1 and Operating Mode
M9999-070808
July 2008
10
MICREL [ MICREL SEMICONDUCTOR ]
