TDA9210
Figure 4. Waveforms (Drive adjustment)
HSYNC
BPCP
BLK
Video IN
BFLK
OSD IN
VOUT1, VOUT2, VOUT3
VOSD
VBRT
VCONT
VBLACK
VDC
Two examples of drive
adjustment (1)
Note :
1.Drive adjustment modifies the following voltages : VCONT, VBRT and VOSD.
Drive adjustment doesn’t modify the following voltages : VDC and VBLACK.
4.10 - Bandwidth Adjustment
A new feature: Bandwidth adjustment, has been
implemented on the TDA9210.
This function has several advantages:
– Depending on the external capacitive load and
on the peak-to-peak output voltage, the band-
width can be adjusted to avoid any slew-rate
phenomenon.
– The preamp bandwidth can be adjusted in order
to reduce electromagnetic radiation, since it is
possible to slow down the signal rise/fall time at
the CRT driver input without too much affecting
the rise/fall time at the CRT driver output.
– It is possible to optimize the ratio of the frequen-
cy response versus the CRT driver power con-
sumption for any kind of chassis, as the preamp
bandwidth adjustment also allows the adjust-
ment of the rise/fall time on the cathode (through
the CRT driver).
– In still picture mode, when a high Video swing
voltage is of greater interest than rise/fall time,
bandwidth adjustment is used to avoid any slew-
rate phenomenon at the CRT driver output and to
meet electromagnetic radiation requirements.
4.11 - CRT Cathode Coupling (Figure 5)
The TDA9210 is designed to be used in DC cou-
pling mode, enabling to build a powerful video sys-
tem on a small PCB Board and giving a substantial
cost saving compared with any other solution
available on the market.
The preamplifier outputs control directly the cut-off
levels.
The output DC level (VDC) is adjusted independ-
ently for each channel from 0.5 V to 2.5 V via reg-
isters 10, 11 and 12.
In DC coupling mode, bit 2 must be set to 1 and
bit3 to 0 in Register 9.
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