TDA4470-M Datasheet, PDF (4/16 Pages) TEMIC Semiconductors – Multistandard Video-IF and Quasi Parallel Sound Processing

TDA4470-M
Standard Switch
To have equal polarity of the video output signal the
polarity can be switched in the demodulation stage in
accordance with the TV standard. Additional a standard
dependent dc level shift in the video amplifier delivers the
same sync. level. In parallel to this, the correct VIF-AGC
is selected for positive or negative modulated VIF signals.
In the case of negative modulation (e.g., B/G standard)
the AM output signal is switched off. For positive modu-
lation (L standard) the AM demodulator and QPS mixer
is active. This condition allows a parallel operation of the
AM sound signal and the NICAM-L stereo sound.
L’ Switch
With a control voltage at Pin 14 the VCO frequency can
be switched for setting to the required L’ value (L’
standard). Also a fine adjustment of the L’-VCO center
frequency is possible via a potentiometer. The L’ switch
is only active for positive modulated video IF-signals
(standard switch in L mode).
AFC Switch
The AFC output signal at Pin 22 can be controlled by a
switching voltage at Pin 19. It is possible to select an AFC
output signal with a rising- or falling AFC curve and to
switch off the AFC.
VCR Mode
For the VCR mode in a TV set (external video source
selected), it is recommendable to switch off the IF circuit.
With an external switching voltage at Pin 6 or 7, the IF
amplifiers are switched off and all signal output levels at
Pins 12, 24, and 25 are according to the internal dc
voltage.
Internal Voltage Stabilizer
The internal bandgap reference ensures constant perfor-
mance independent of supply voltage and temperature.
4 (16)
TELEFUNKEN Semiconductors
Preliminary Information
Rev. A2, 15-Oct-96