CXA1884N View Datasheet(PDF) - Sony Semiconductor
Part Name
Description
Manufacturer
CXA1884N Datasheet PDF : 16 Pages
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CXA1884N
5) IF limiter
The IF limiter of this IC features a gain of about 100dB. To this effect, the following points should be
considered for the wiring connecting IF limiter input pin (Pin 5) and decoupling capacitor pins (Pins 6 and 7).
(a) Wiring to mixer output (Pin 3) and IF limiter input (Pin 5) should be as short and as far apart as possible
to avoid neutral interference.
(b) Connect a decoupling capacitor to IF limiter IF P1 (Pin 6) and IF P2 (Pin 7).
Here the decoupling capacitor should be positioned as close as possible to each pin and the wiring be as
short as can be.
(c) As IF limiter output shows at QD (Pin 8), keep the wiring connected to QD pin R, L, C and the ceramic
discriminator as short as possible. Interference to the mixer output, IF limiter input and others must be
kept to a minimum.
3
4
5
6
7
8
VCC
Wiring as short and as far apart as possible As short as possible
Fig. 2
6) Detector
The detector is of the quadrature type. To phase shift, either R, L, C resonance circuit or the ceramic
discriminator is connected to Pin 8.
The phase capacitor of the quadrature detector is built-in. FM (FSK) signals demodulated by this detector have
their high frequency components dropped by the LPF formed inside from CRs, to be output at DET OUT (Pin 9).
DET OUT output impedance is about 3kΩ.
For the CXA1884N ceramic discriminator, CDB 455 C3 (Murata Production) is recommended.
7
8
9
7
8
9
Coil
VCC
(a) Coil
DET OUTPUT
Fig. 3
4.7k
DET OUTPUT
Ceramic
discriminator
VCC CDB 455 C3
(b) Ceramic discriminator
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