RF83 Datasheet, PDF (15/22 Pages) List of Unclassifed Manufacturers – 300~440MHz ASK/OOK Receiver

RF83//RF83C/RF83L/RF83CL ASK/OOK Receiver V2.0
C_AGC = AGC capacitor value
∆t = droop recovery time
∆V = droop voltage
For example, if user desires ∆t = 10ms and chooses a 4.7µF C_AGC, then the allowable droop is about
144mV. Using the same equation with 200nA worst case pin leakage and assuming 1µA of capacitor
leakage in the same direction, the maximum allowable ∆t (shutdown time) is about 0.56s for droop recovery
in 10ms.
The ratio of decay-to-attack time-constant is fixed at 10:1 (that is, the attack time constant is
1/10th of the decay time constant). Generally the design value of 10:1 is adequate for the vast majority of
applications. If adjustment is required the constant may be varied by adding a resistor in parallel with the
C_AGC capacitor. The value of the resistor must be determined on a case by case basis.
13.1.5. Step 5: Selecting the Demod Filter Bandwidth
For RF83,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 1. Bandwidth must be selected
according to the application. The demodulator bandwidth should be set according to equation 8.
(8) Demodulator bandwidth = 0.65 / 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.
SEL0
SEL1
Demodulator Bandwidth
Sweep Mode
Fixed Mode
1
1
5.0KHz
10KHz
0
1
2.5KHz
5KHz
1
0
1.25KHz
2.5Hz
0
0
0.625KHz
1.25Hz
Table 1. Nominal Demodulator Filter Bandwidth vs. SEL0, SEL1 and Operating Mode
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