U2514B-AFNG3 TEMIC [TEMIC Semiconductors], U2514B-AFNG3 Datasheet - Page 7

• Manufacturer Part Number: U2514B-AFNG3
• Description: AM/FM Receiver for Digital Tuning with FM-Stereo Decoder
• Manufacturer: TEMIC [TEMIC Semiconductors]

TELEFUNKEN Semiconductors
Rev. A2, 04-Nov-96
CERES
A ceramic resonator of 456 kHz parallel resonance
frequency (at 30 pF chip internal load capacitance) is
connected between CRES (Pin 20) and GND (necessary
for the pilot regeneration). It should be mounted very
close to Pin 20 in order to avoid spurios radiation. In the
AM (V26 < 1.1 V) search (V22 < 0.8 V) mode, the
resonator is used for stop signal generation. The parallel
resonance frequency is then reduced down to 455 kHz by
adjusting the current into Pin 9 AMSADJ.
LPF
A PLL circuit is used for the pilot regeneration of the
stereo decoder. Therefore, a loopfilter consisting of an RC
network is connected between LPF (Pin 21) and GND.
CERES
20
LPF
12450
21
GND
Figure 18.
Figure 19.
25 k
50 k
Preliminary Information
VREF
VREF
12449
MPXIN
The MPX signal is applied to MPXIN (Pin 24). It is fed
to the stereo decoder. The input resistance into Pin 24 is
approximately 10 k
channel separation by an RC network between MPXIN
and MPXOUT (Pin 25) due to the tolerances in group
delay of the IF filter.
MPXOUT
In order to drive both the compensation network to
MPXIN (Pin 24) and an optional RDS decoder, the
MPXOUT (Pin 25) has a low output impedance. The dc
level is 1.2 V in FM mode (depending on the
discriminator coil alignment) and 0.7 to 1.5 V in AM
mode (depending on the signal level).
OUTR/OUTL
The open collector output of OUTR/OUTL (Pin 18/19)
requires an external resistor of about 4.7 k
The de-emphasis may be achieved by an additional
parallel capacitor.
MPXIN
12452
24
10 k
W
GND
. It is recommended to align the
VREF
Figure 20.
Figure 21.
Figure 22.
U2514B
MPXOUT
60 k
OUTL
OUTR
18,19
VREF
25
W
12451
to ground.
7 (15)
12453