SGS Thomson Microelectronics TDA9207 Datasheet

150 MHz PIXEL VIDEO CONTROLLER FOR MONITORS

FEATURE

■ 150 MHZ PIXEL RATE

■ 2.7 ns RISE ANDFALL TIME

2

■ I

C BUS CONTROLLED

■ GREY SCALE TRACKING VERSUS BRIGHT-

NESS

■ OSD MIXING

■ NEGATIVE FEED-BACK FOR DC COUPLING

APPLICATION

■ INTERNAL POSITIVE FEED-BACK FOR LCD

APPLICATION

■ 0.5~4.5 V DACs FOR BLACK LEVEL RESTO-

RATION (AC-COUPLING APPLICATION) OR
CUT-OFF CONTROLS (FOR DC-COUPLING
APPLICATION USING THE ST AMPLIFIERS
TDA9533/9530)

■ BEAM CURRENT ATTENUATION (ABL)

■ PEDESTRAL CLAMPING ON OUTPUT

STAGE

■ POSSIBILITY OF LIGHT OR DARK GREY

OSD BACKGROUND

■ OSD INDEPENDENT CONTRAST CONTROL

■ ADJUSTABLE BANDWIDTH

■ INPUT BLACK LEVEL CLAMPING WITH

BUILT-IN CLAMPING PULSE

■ STAND-BY MODE

■ 5 V TO 8 V POWER SUPPLY

■ SYNC CLIPPING FUNCTION (SOG)

DESCRIPTION

The TDA9207 is an I2C Bus controlled RGB pre­amplifier designed for Monitor application, able to
mix the RGB signals coming from any OSD de­vice. The usual Contrast, Brightness, Drive and
Cut-Off Controls are provided.

In addition, it includes the following features:
– OSD contrast,
– Bandwidth adjustment,
– Grey background,
– Internal back porchclamping pulse generator.

TDA9207

INCLUDING CUT-OFF INPUTS

SHRINK DIP24

(Shrink Plastic Package)

ORDER CODE: TDA9207

The RGB incoming signals are amplified and
shaped todrive any commonlyused videoamplifi­ers without intermediate follower stages. Even
though encapsulated in a 24-pin package only,
this IC allows any kind of CRT Cathode coupling :

– AC coupling with DC restore,
– DC coupling with Feed-back from Cathodes,
– DC coupling with Cut-Off controls of the Video

amplifier (ST Amplifiers TDA9533/9530).

As forany STVideo pre-amplifier, theTDA9207 is
able to drive a real load without any external inter­face.

One of the main advantages of ST devices is their
ability to sink and source currents while most of
the devices from our competitors have problems
to sink largecurrents.

These driving capabilities combined with an origi­nal outputstage structuresuppress any static cur­rent on the output pins and therefore reduce dra­matically the power dissipation of the device.

Extensive integrationcombined with high perform­ance and advanced features make the TDA9207
one of the best choice for any CRT Monitor in the
14” to 17” range.

Perfectly matched with the ST Video Amplifiers
TDA9530/33, these 2 products offer a complete
solution for high performance and cost-optimized
Video Board Application.

Version 4.2

March 2000 1/22

1

TDA9207

1 -PIN CONNECTIONS

IN1

ABL

IN2

GNDL

IN3

GNDA

V

CCA

NC
OSD1
OSD2

OSD3

FBLK

1
2
3

4

5

6
7
8

9
10
11

12

24
23

22
21
20
19

18

17
16
15

14
13

BLK
HSYNC or BPCP

CO1/FB1
OUT1

V

CCP

OUT2
GNDP
OUT3
CO3/FB3
CO2/FB2
SDA
SCL

2 -PIN DESCRIPTION

Pin Number Symbol Description

1 IN1 Red Video Input
2 ABL ABL Input
3 IN2 Green Video Input
4 GNDL Logic Ground
5 IN3 Blue Video Input
6 GNDA Analog Ground
7V
8 NC Not Connected

9 OSD1 Red OSD Input
10 OSD2 Green OSD Input
11 OSD3 Blue OSD Input
12 FBLK Fast Blanking
13 SCL SCL
14 SDA SDA
15 CO2/FB2 Green Cut-off Output/Feedback Input
16 CO3/FB3 Blue Cut-off Output/Feedback Input
17 OUT3 Blue Video Output
18 GNDP Power Ground
19 OUT2 Green Video Output
20 V
21 OUT1 Red Video Output
22 CO1/FB1 Red Cut-off Output/Feedback Input
23 HSYNC

24 BLK Blanking Input

CCA

CCP

BPCP

Analog VCC(5V)

Power VCC(5 V to 8 V)

HSYNC
BPCP

2/22

3 - BLOCK DIAGRAM

TDA9207

V

REF

1

IN1

Clamp

IN2

3

IN3

5

ABL

GNDL

GNDA

VCCA

NC

2

BPCP

4

6
7

8

23 14 13 9 10 11

HSYNC SDA SCL

or BPCP

Contrast/8bit

Latches

Decoder

BLK FBLK VCCP

2

I

C

Bus

24

Contrast

D/A

OSD
Cont.

4bits

12

Output Clamp Pulse

(OCL)

Drive

Green Channel

Blue Channel

Brightness

8bits

OSD1 OSD2 OSD3

Drive

3x8bits

I C

Cut-off

8bits

20

Output

Stage

V

Output

DC Level

REF

4bits

TDA9207

OUT1

21

CO1/FB1

22

OUT2

19

CO2/FB2

15

OUT3

17

CO3/FB3

16

GNDP

18

See Figure 12 for complete BP CP and OCL generation diagram

4 - FUNCTIONAL DESCRIPTION

4.1 RGB Input

The three RGBinputs have to be supplied through
coupling capacitors (100 nF).

The maximum input peak-to-peak video amplitude
is 1 V.

The input stage includes a clamping function. The
clamp uses the input serial capacitor as a”memo­ry capacitor”.

To avoid a discharge of the serial capacitor during
the line (due to leakage current), the input voltage
is referenced to the ground.

The clamp is gated by an internally generated
”Back Porch Clamping Pulse” (BPCP). Register 8
allows to choose the way to generate this BPCP
(see Figure 1).

When bit 0 is set to 0, the BPCP is synchronized
on the trailing or leading edge of HSYNC (Pin 23)
(bit 1 =0: trailing edge, bit 1 = 1: leading edge).

3/22

TDA9207

Additionally, the IC automatically works with either
positive or negative HSYNC pulses.

– When bit 0 is set to 1,BPCP is synchronized on

the leading edge of the blanking pulse BLK
(Pin 24).One can use a positive or negative
blanking pulse by programming bit 0 in
Register 9 (See I2C Table 3).

– BPCPwidth can be adjusted with bit2 and3 (see

Register 8, I2C table 2).

– If the application already provides the Back

Porch Clamping Pulse, bit 4 must be set to 1
(providing a direct connection between Pin 23
and internal BPCP).

4.2 Synchro Clipping Function

This function is available on channel 2 (Green
Channel). When using the Sync On Green (SOG)
(Synchro pulse included in the green channel in-

Figure 1.

R8b0=0 and R8b1=0

HSYNC/BPCP (Pin23)

Internal BPCP

put) the synchro clipping function must be activat­ed (bit 7 set to 1 in register 9) in order to keep the
right green output levels and avoid unbalanced
colours.

4.3 Blanking Input

The Blanking pin (FBLK) isTTL compatible.
The Blanking pulse can be:
– positive or negative
– line or Composite-type (but not Frame-type).

4.4 Contrast Adjustment (8 bits)

The contrast adjustment is made bycontrolling si­multaneously the gain ofthe three internal amplifi­ers through the I2C bus interface. Register 1 al­lows the adjustment in arange of 48 dB.

R8b0=0 and R8b1=1

HSYNC/BPCP (Pin23)

Internal BPCP

R8b0=1

R8b4 =1

HSYNC/BPCP (Pin23)

BLK (Pin24)

Internal BPCP

Internal BPCP

4.5 ABL Control

The TDA9207 includes an ABL (automatic beam
limitation) input to attenuate the RGB Video sig­nals depending on the beam intensity.

The operating rangeis 2 V (from3 V to1 V). A typ­ical 15 dB maximum attenuation is applied to the
output signal whatever the contrast adjustment is.
(See Figure 2 ).

When the ABL feature is not used, the ABL input
(Pin 2) must be connectedto a5V supplyvoltage.

4/22

TDA9207

Figure 2.

Attenuation (dB)

0

-2

-4

-6

-8

-10

-12

-14

-16
0

(V)

V

ABL

4321

5

4.6 Brightness Adjustment (8 bits)
Brightness adjustment is controlled by the I2C Bus

via Register 2. It consists of adding the same DC
voltage to the three RGBsignals,after contrast ad­justment. When the blanking pulse equals 0, the
DC voltageis set toa value whichcan be adjusted
between 0 and 2V with 8mVsteps (see Figure 3).

The DC output level is forced to the ”Infra Black”
level (VDC) when the blanking pulseis equal to 1.

4.7 Drive Adjustment (3 x 8 bits)
In order to adjust the white balance,the TDA9207

offers the possibility of adjusting separately the
overall gain ofeach channel thanks to the I2C bus
(Registers 3, 4 and 5).

The very large drive adjustment range (48 dB) al­lows different standards or custom color tempera­tures.

It can also be usedto adjust the output voltages at
the optimum amplitude to drive the CRT drivers,
keeping the whole contrast control for the end­user only.

The drive adjustment is located after the Contrast,
Brightness and OSD switch blocks, so it does not
affect the white balance setting when the BRT is
adjusted. It also operates on the OSD portion of
the signal.

4.8 OSD Inputs

The TDA9207 allows to mix the OSD signals into
the RGB main picture. The four pins dedicated to
this function are the following:

– Three TTL RGB inputs (Pins 9, 10,11) connect-

edtothethree outputs ofthe corresponding OSD
processor.

– One TTL fast blanking input (Pin 12) also con-

nected tothe FBLK output ofthe OSD processor.

When a high level is present on the FBLK, the IC
acts as follows:

– The three main picture RGB input signals (IN1,

IN2, IN3) are internally switched to the internal
input clamp reference voltage.

– The three outputsignals are setto the voltage

corresponding to the three OSD input logic
states (0 or 1). (See Figure 3).

If the OSD input is at low level, the output and
brightness voltages (V

) are equal.

BRT

If the OSD input is at high level,the output voltage
is V
an I2C bus-controlled voltage.

, where V

OSD

OSD=VBRT

+ OSD and OSD is

OSD variesbetween0 V to 4.9 V by 320 mV steps
via Register 7 (4 bits). The same variation is ap­plied simultaneously to the three channels provid­ing the OSD contrast.

The grey color can be obtained on output signals
when:

– OSD1 = 1, OSD2 = 0 and OSD3 = 1,
– A special bit(bit 5 or 6) in Register 9 is set to 1.
If R9b5 is set to 1, light grey is obtained on output.
If R9b6is setto 1, dark grey is obtained on output.
In thecase where R9b5 and R9b6are setto 0, the

normal operation is provided on output signals.

4.9 Output Stage

The overall waveforms of the output signal are
shown in Figure 3 and Figure 4. The three output
stages, which are large bandwidth output amplifi­ers, areabletodeliver up to 4.4VPPfor0.7VPPon
input.

When a high level is applied on the BLK input
(Pin 24), the three outputs are forced to ”Infra
Black” level(VDC) thanks to a sample and holdcir­cuit (described below).

The black level (which is the output voltage out­side the blanking pulse with minimum brightness
and no Video input signals) is 400 mV higher than
VDC.

The brightness level (V

) is then obtained by

BRT

programming register 2(see I2C table 1).
The sample and hold circuit is used to control the

”Infra Black” level in the rangeof 0.5V to 2.5 V via
Register 6 (in case of AC coupling) or Registers
10, 11, 12 (in case of DC coupling) .

This sampling occurs during an internal pulse
(OCL) generated inside the blanking pulse win­dow.

Refer to “CRT cathode coupling” part for further
details.

5/22

TDA9207

Functioning with 5 V Power V

CC

To simplify the application, it is possible to supply
the power VCCwith 5V (insteadof 8V nominal)at
the expense of output swing voltage.

Functioning without Blanking Pulse

If noblanking pulse isapplied tothe TDA9207, the
internal BPCP can be connected to the sample

Figure 3. Waveforms VOUT, BRT, CONT, OSD

HSYNC

BPCP

BLK

Video IN

FBLK

OSD IN

and hold circuit (Register 8, bit 7 = 1 and BLK pin
grounded) so that the output DC level is still con­trolled by I2C.

To ensurethe device correct behavior in the worst
possible conditions, the Brightness Register must
be set to 0.

Notes :

V

1.
V

2.
V

3.
V

4.
V

5.

DC
BLACK
BRT
CONT
OSD

V
V
V

V
V

0.5 to 2.5V

=

V

=

V

=

V

=

V

=

V

V

OUT1 ,

(4)

CONT

(5)

OSD

(3)

BRT

(2)

BLACK

(1)

DC

+ 0.4V

DC

+ BRT (with BRT = 0 to 2V)

BLACK

+ CONT = k x Video IN (CONT = 4.4VPPmax. for VIN= 0.7VPP)

BRT

+ OSD (OSD max. = 4.9VPP, OSD min = 0VPP)

BRT

OUT2

,V

OUT3

OSD

CONT
BRT

0.4V fixed

6/22

Figure 4. Waveforms (Drive adjustment)

HSYNC

BPCP

BLK

Video IN

BFLK

OSD IN

V

OUT1,VOUT2,VOUT3

V

OSD

V

CONT

TDA9207

V

BRT

V

BLACK

V

DC

Note :

1.Drive adjustment modifies the following voltages : V
Drive adjustment doesn’t modify the following voltages : V

Two examples of drive
adjustment

4.10 Bandwidth Adjustment

A new feature: Bandwidth adjustment, has been
implemented on the TDA9207.

This function has several advantages:
– Depending on the external capacitive load and

on the peak-to-peak output voltage, the band­width can be adjusted to avoid any slew-rate
phenomenon.

– The preamp bandwidth can be adjustedinorder

to reduce electromagnetic radiation, sinceit is
possible to slow down the signal rise/fall time at
the CRT driverinput 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 con­sumption for any kind of chassis, as the preamp
bandwidth adjustment also allows the adjust­ment of the rise/fall timeonthe cathode (through
the CRT driver).

(1)

CONT,VBRT

DC

and V

and V

OSD

BLACK

.

.

– In still picture mode, when a high Video swing

voltage is of greater interest than rise/fall time,
bandwidth adjustmentis used to avoid any slew­rate phenomenon attheCRTdriver output and to
meet electromagnetic radiation requirements.

4.11 CRT Cathode Coupling

The powerfull multiplex capability of the TDA9207
allows touse the device with several kinds of CRT
cathode coupling.

4.11.1 AC coupling withDC restore ( Figure 5)
In this mode the output DClevel (VDC) is adjusted

simultaneously for the 3 channels from 0.5 V to

2.35 V via Register 6(4 bits). Thecut-offvoltage is
programmed independently for each channelfrom

0.17 V to 4.6 V using registers 10, 11, 12 (8 bits
each, see I2C Table 1).

7/22