SL6649-1 Zarlink Semiconductor Inc, SL6649-1 Datasheet - Page 12

• Manufacturer Part Number: SL6649-1
• Description: 200MHz DIRECT CONVERSION FSK DATA RECEIVER
• Manufacturer: Zarlink Semiconductor Inc

PAGER APPLICATION EXAMPLE
application is shown in Figure 13 (b). Only 3 integrated circuits
are required to perform all the functions of a tone only pager.
These are SL6649-1 direct conversion radio receiver and the
MV6639 POCSAG decoder plus a 1 volt E
Epson SPM28C51).
monitors the battery voltage. The interface between the
decoder and receiver consists of only 3 connections excluding
the supplies.
OPERATION AT OTHER FREQUENCIES AND
DATA RATES
appropriate for frequencies nominally around 153MHz. In order
to use the receiver at other frequencies it is necessary to
change the capacitor C4 which is resonant with the transformer
T1, and L2 and L4 in the oscillator circuit.
and C15 such that the reactance of these is equal to 100Ω at
the required frequency.
A typical 1 volt pager system suitable as a wrist watch
The SL6649-1 receives and demodulates the data, and
The values given in the components list for figure 6 are
It is also necessary to change the values of capacitors C13
Figure 13(b): Tone Pager Applications Example Showing Interface with SL6649-1 Receiver
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PROM (eg. Seiko
POCSAG decoder for tone only and/or pager messaging at 512
or 1200 baud. A 32kHz watch crystal is used as the reference
frequency for the decoder.
power not only the receiver, but an alternative higher voltage
E
message pager.
frequency and stability. In order to use the receiver at higher
data rates it is only necessary to reduce the value of C8, for
example, at 1200bps, C8=470pf.
demonstrate terminal sensitivity. It is possible to connect an
antenna to the board with suitable matching but no guarantee
can be given regarding field strength sensitivity. However, with
a suitably designed combination of PCB and antenna, a
sensitivity of 5µV/M should be attainable.
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PROM and microprocessor/LCD driver for a full tone and
The MV6639 performs all the functions required for a
The decoder voltage doubler output V
It is of course necessary to use a crystal of the required
A demonstration board has been designed specifically to
CC
2 is available to
SL6649-1
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