U2514B Datasheet, PDF (5/15 Pages) TEMIC Semiconductors – AM/FM Receiver for Digital Tuning with FM-Stereo Decoder

AMIFIN
3.3 k
13
AMIFIN
VREF
12421
Figure 10.
FMDET
U2514B
VREF
150 mA
Figure 12.
15
FMDET
12422
W The input impedance of the AM IF amplifier is 3.3 k
according to the required impedance of most ceramic
filters. The input refers to VREF (Pin 14).
The discriminator allows the connection of a ceramic
resonator or LC tank. A minimization of THD and
adjustment of center frequency versus temperature can
only be achieved by using a LC tank. This performs a
temperature independent stop signal.
FMIFIN
AFSM
25 MPXOUT
11 AFSM
40 mA
12
FMIFIN
100 k
12423
GND
Figure 13.
12424
Figure 11.
W The input impedance of the FM IF amplifier is 330
according to the required impedance of most FM ceramic
filters. The input referes to GND (Pin 16).
A capacitor is connected between AFSM (Pin 11) and
GND for smoothing of the FM-AF. This is necessary to
generate a modulation independent stop signal. (Because
the deviation of the FM signal (75 kHz) can be greater
than the stop signal window (25 kHz)). In the
AM-search-mode, the external capacitor smoothes the
demodulated AM-IF-signal.
TELEFUNKEN Semiconductors
5 (15)
Rev. A2, 04-Nov-96
Preliminary Information