AT86RF211SAHWR E2V, AT86RF211SAHWR Datasheet - Page 20

• Manufacturer Part Number: AT86RF211SAHWR
• Manufacturer: E2V

Specifications of AT86RF211SAHWR

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Modulation Type: FSK
• Product Depth (mm): 7mm
• Product Length (mm): 7mm
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / Rohs Status: Compliant

4.2.11
Table 4-5.
Note:
20
Name
NDB
SDB
MDB
WDB
Please refer to the Application Note “Data Demodulation and Crystal Selection for the AT86RF211S”.
0894C–WIRE–11/08
FSK Demodulator
Discriminator Bandwidth Selection
The structure of the FSK demodulator is based on an oscillator.
Figure 4-16. FSK Demodulator Schematic
The oscillator’s natural frequency is F
oscillator’s output (point A in
The XOR function translates the difference into a pulse duty cycle (point B). Thereafter, by low-pass fil-
tering of the signal, a mean voltage of the signal is obtained (point C).
This demodulation’s architecture is thereby analog and as the output voltage is proportional to the input
frequency, enables transmission of a continuous stream of data of the same value. It is not therefore
mandatory to use Manchester encoding; the first bit is correctly demodulated.
The oscillator’s feedback resistor controls the center frequency F
of a dummy FSK demodulator driven by a 455 kHz internal reference frequency, which is a division of
the reference crystal. The discrete components connected to pin 32 DISCFILT constitute the loop filter of
the PLL stabilizing the 455 kHz signal.
The input RBW resistor controls the discriminator bandwidth.
Applicable
Mode
RF211
RF211S
RF211
RF211S
RF211S
RF211S
Fin
Maximum FSK
Deviation (kHz)
±25 kHz
±50 kHz
±75 kHz
±125 kHz
RBW
Figure 4-16
Gain at 2.4V
Conversion
(mV/kHz)
D
F D
and it actually oscillates at the Fin frequency. The signal at the
28
14
is proportional to the frequency difference between Fin and F
9
5
Oscillator
Conversion
Gain at 3V
(mV/kHz)
6.5
34
17
11
A
Table 4-5
D
. It is adjusted according to the output
Bit Configuration
FSKBW = 0
DISCRANGE = 11
FSKBW = 1
DISCRANGE = 10
DISCRANGE = 01
DISCRANGE = 00
outlines some possible choices:
B
e2v semiconductors SAS 2008
AT86RF211S
Comments
Compatible with
AT86RF211
AT86RF211S only
C
D
.