TDA8012AM Datasheet, PDF (4/16 Pages) NXP Semiconductors – Low power PLL FM demodulator for satellite TV receivers

Philips Semiconductors
Low power PLL FM demodulator for
satellite TV receivers
Product specification
TDA8012AM
PINNING
SYMBOL
CDF1
CDF2
PD+
PD−
IFI1
IFI2
GND
V_CC
AGCO
V_th(AGC)
VIDEO
LF1
LF2
OSCGND
VCO1
VCO2
AFCF
KEY
AFC/CDO
AFCOS
PIN
DESCRIPTION
1 carrier detector filter 1 input
2 carrier detector filter 2 input
3 positive peak detector output
4 negative peak detector output
5 intermediate frequency input 1
6 intermediate frequency input 2
7 general ground
8 supply voltage
9 automatic gain control output
10 automatic gain control threshold
voltage input
11 baseband signal output
12 loop filter 1 input
13 loop filter 2 input
14 oscillator ground
15 oscillator tank circuit 1 input
16 oscillator tank circuit 2 input
17 automatic frequency control filter
input
18 key pulse input
19 automatic frequency control
/carrier detector output
20 automatic frequency control offset
input
handbook, halfpage
CDF1 1
20 AFCOS
CDF2 2
PD+ 3
19 AFC/CDO
18 KEY
PD− 4
17 AFCF
IFI1 5
16 VCO2
TDA8012AM
IFI2 6
15 VCO1
GND 7
14 OSCGND
VCC ₈
13 LF2
AGCO 9
Vth(AGC) ₁₀
12 LF1
11 VIDEO
MBH931
Fig.2 Pin configuration.
FUNCTIONAL DESCRIPTION
The TDA8012AM is a low power PLL FM demodulator
designed for use in satellite TV reception systems.
The demodulator is based on a PLL structure including a
fully balanced two-pin VCO. A high gain IF amplifier
ensures a high input sensitivity. The video output voltage
is supplied through a highly-linear video buffer with a low
output impedance. The centre frequency of the VCO and
the loop characteristics can be set by external components
(see Fig.4).
The circuit provides an AGC signal which is used to drive
a gain-controlled IF amplifier (TDA8011T or TDA8010AM)
for a stable PLL demodulation characteristic.
An analog AFC voltage is available. This signal fits in with
the input of the A/D converter port of the PLL frequency
synthesizer (TSA5055). The AFC function may be keyed
to address D2MAC systems.
The TDA8012AM includes a Carrier Detector (CD) used
for channel detection during search procedures.
1997 May 26
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