AT86RF211SAHW Atmel, AT86RF211SAHW Datasheet - Page 22

• Manufacturer Part Number: AT86RF211SAHW
• Manufacturer: Atmel

Specifications of AT86RF211SAHW

• Lead Free Status / Rohs Status: Compliant

4.2.12.2
Figure 4-19. Data Slicing Parameters Setup Example
22
0894C–WIRE–11/08
Demodulated
Internal Mode
DISCOUT:
Data
The internal mode uses the output of a DAC as the comparison level. Once this threshold has been cor-
rectly set, an absolute data slicing of the demodulated signal is possible; there is no need for a DC-free
modulation scheme (it is possible to send a 0 or a 1 infinitely).
Figure 4-18. Data Slicer Schematics
To operate this way, one must make sure that the 0 and 1 levels at the output of the discriminator appear
on both sides of the comparison level in order for the decision to be made properly.
To set the discriminator and data slicer accordingly:
• The output DC level of the discriminator DISCOUT can be measured (using the A/D embedded
• The DC level can be shifted up or down at the output of the discriminator through the DTR[1:0] bit:
• The comparison threshold can be tuned around V
converter)
possible, with an LSB equal to 15 mV per volt of supply voltage. V
0111, and the RESET value is 1000.
– DTR[1] = 1: +180 mV + 77 × (V
– DTR[0] = 1: -180 mV - 77 × (V
Choice of internal or
external reference for
the data slicer
DATAMSG
OK
+
-
CC
CC
- 2.4V)
- 2.4V)
Vdd/2
+
-
+
Σ
CC
+
-
/2 through the DTR[5:2] bit. 16 levels are
+
Not OK
100 kΩ
4 bits
Comparator Threshold
CC
SKFILT
/2 corresponds to DTR[5:2] =
DSIN
DISCOUT
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AT86RF211S
Time