STV5730A STMicroelectronics, STV5730A Datasheet - Page 14

• Manufacturer Part Number: STV5730A
• Description: Multimedia Misc On-Screen Display
• Manufacturer: STMicroelectronics
• Type: Satellite Receiverr

Specifications of STV5730A

• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Package / Case: SO
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

STV5730A
14/20
FUNCTIONAL DESCRIPTION (continued)
5.1 - Internal Bias Mode
This mode is intended for minimal cost applica-
tions. C10 must be cleared.
The luma levels of the OSD output signal are as
follows :
- LEBLACK : black level
- LESYNC : sync level
- LESCREEN : page background level
- LECHAR : character level
LEBLACK is also used to clamp the VIDEO IN
signal and to create the character border.
5.2 - External Bias Mode
This mode is intended to give more flexibility to the
user. C10 must be set.
The LESCREEN and LECHAR levels may be user
defined relatively to the internal LEBLACK level.
The final luma amplitude should not be greater than
the peak white level.
These levels may be static or dynamic.
Dynamic levels can be easily generated by analog
sum of the R/G/B and CO STV5730A outputs (a
few resistors are necessary) to give grey scale
character shading in the mixed mode.
C0 is useful to control the character foreground
luma level.
6 - THE CHROMA GENERATOR
The STV5730Aencoder operates in full page mode
only. It may performPAL or NTSC encodingaccord-
ing to the C8 control bit.
A 4*fsc chroma quartz crystal is necessary
(fsc = 4.43MHz for PAL, 3.58MHz for NTSC).
The encoder can be turned off by the M6 mode bit
for black & white or for SECAM applications.
The character encoding is controlled by the C9
control bit.
The chroma signal is output on the COUT pin for
external filtering and for attenuation if necessary. It
is then re-entered on the CIN pin and added to the
YIN pin signal to create the final CVBS output
signal.
The chroma saturation is controlled by the
STV5730A :
- burst nominal amplitude : 320mV
- blue or yellow colors nominal amplitude :
- red, magenta, green or cyan colors nominal am-
nominal value : 1.25V
nominal value : LEBLACK - 300mV
nominal value : LEBLACK + 150mV
nominal value : LEBLACK + 650mV
420mV
plitude : 580mV
PP
PP
PP
7 - THE MARKERS
The STV5730A can generate 3 different markers
that can be activated simultaneously (i.e. on the
same page).
The following marker features are performed :
- Blinking character, character background off.
- Not blinking character, character background on
- Blinking character, character background on.
8 - THE TRANSLUCENT MIXED MODE
Figure 4 :
The VIDEO OUT1 and VIDEO OUT2 outputs may
be summed via two external resistors to create a
translucent text (mixed mode). In this case, the
background picture is still visible behind the text.
The background picture visibility (or level of trans-
lucence is controlled by the resistor ratio.
Another benefit from this function is to allow
PAL/SECAM/NTSC multistandard applications to
be built with no SECAM chroma re-insertion filter
and no additional control switches.
The sum may be cancelled by setting the M8 mode
bit. In this case, the VIDEO OUT2 pin is in high
impedance state and the resistor network delivers
VIDEO OUT1 only.
When using the resistor network, please set M8 in
the following cases :
- in full page mode
- when OSD in not displayed
- to select opaque text. This allows the viewer to
The DC levels of the VIDEO OUT1, VIDEO OUT2
and the sum signals are high enough to directly
drive a NPN emitter follower driver (see Table 1).
The character foreground blinks (BK = 1, BE = 0
or C1 = 1).
(C1 = 0, BE = 1).
The character foreground blinks and the charac-
ter background remains (BK = 1, BE = 1, C1 = 0).
select by software the preferred display mode.
disa ble
The Translucent Mixed Mode Output
Configuration
VIDEO OUT2
VIDEO OUT1
S TV5730A
28
1
R1
R2
S