SM1212E433 Semtech, SM1212E433 Datasheet - Page 31

• Manufacturer Part Number: SM1212E433
• Description: RF Module For SX1212
• Manufacturer: Semtech
• Series: -r
• Type: Transceiver, ISMr

Specifications of SM1212E433

• Frequency: 433MHz
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: SX1212E

In addition to the Peak OOK threshold mode, the user can alternatively select two other types of threshold
detectors:
In the first example, the higher cut-off frequency enables a sequence of up to 8 consecutive “0” or “1” to be
supported, whilst the lower cut-off frequency presented in the second example allows for the correct reception of up
to 32 consecutive “0” or “1”.
The Bit Synchronizer (BitSync) is a block that provides a clean and synchronized digital output, free of glitches.
The BitSync can be disabled through the bits RXParam_Bitsync_off, and by holding pin IRQ1 low. However, for
optimum receiver performance, its use when running Continuous mode is strongly advised. With this option a
DCLK signal is present on pin IRQ_1.
The BitSync is automatically activated in Buffered and Packet modes. The bit synchronizer bit-rate is controlled by
MCParam_BR. For a given bit rate, this parameter is determined by:
Rev 2 – June 18th, 2009
ADVANCED COMMUNICATIONS & SENSING
Fixed threshold: The value is selected through the MCParam_OOK_floor_thresh register (refer to section
3.4.10.1 for further information concerning optimization of the floor threshold).
Average threshold: Data supplied by the RSSI block is averaged with the following cutoff frequency:
3.4.11. Bit Synchronizer
3.4.10.3. Alternative OOK Demodulator Threshold Modes
DCLK in continuous
Raw demodulator
To pin DATA and
RXParam
RXParam
BitSync Output
(FSK or OOK)
output
mode
BR
_
_
Figure 24: BitSync Description
OOK
OOK
=
IRQ_1
DCLK
DATA
64
_
_
*
cutoff
cutoff
[
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1
+
MCParam
F
=
=
XTAL
11
00
⇒
⇒
Fcutoff
Fcutoff
_
BR
]
=
=
32
8
BR
BR
*
*
π
π
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