la7688b Sanyo Semiconductor Corporation, la7688b Datasheet - Page 16

• Manufacturer Part Number: la7688b
• Description: Pal/ntsc Color Television-use Single-chip Lsi
• Manufacturer: Sanyo Semiconductor Corporation

OSD block Input signals and test conditions
Set up the following conditions unless otherwise specified for each test item.
(VIF, SIF blocks : No signal)
1. INT IN (pin 10) : No signal
2. EXT IN (pin 14) : Input signal color bar : 0dB (PAL)
3. S-CHROMA IN (pin 13) : DC-sharp + chroma signal
4. SW conditions : EXT VIDEO selected. SW36 shorted (SW36 : ON)
5. VR control position : Contrast VR - 4V, sharpness VR - 2V, others - control center
6. V CC , I CC conditions : V CC = 7.8V, I CC = 12mA
7. The OSD input waveform is such that :
[OSD block]
OSD input level
OSD input DC
voltage
F-BLK input
threshold level
OSD output
pedestal
difference
OSD output max
OSD output min
OSD signal
frequency
characteristics
TV-OSD crosstalk
(C-Y)
OSD-TV crosstalk
(C-Y)
OSD CH between
crosstalk (G-Y)
(1) a pulse signal of blanking period 0V and scanning period 0.7V is input
(2) no signal
(3) a 100mVp-p AC sweep (100kHz to 10MHz) of blanking interval 0V and scanning period 0.35V is input
Parameter
E OSD
V OSD
V 28 TH
V OSD R
V OSD G
V OSD B
E OSD R1
E OSD G1
E OSD B1
E OSD R2
E OSD G2
E OSD B2
BW OSD
C TTVR
C TTVG
C TTVB
C TOSDR
C TOSDG
C TOSDB
C TOSD
Symbol
O-33
O-29B
O-30B
O-31B
O-33
O-35
O-34
O-33
O-35
O-34
O-33
O-35
O-34
O-33
O-33
O-35
O-34
O-33
O-35
O-34
O-33
O-34
point
Test
(1)
(2)
(2)
(2)
(1)
(1)
(3)
(2)
(3)
(3)
signal
Input
Measure the DC voltage amplitude.
Measure the DC voltage.
Raise the voltage at I-28 from 0.5V until
the B output becomes OSD mode.
Measure the voltage at I-28 at that
moment.
Measure the R, G, and B's DC voltage.
Measure the R, G, and B's DC voltage
amplitude.
Measure the R, G, and B's DC voltage
amplitude.
Measure the frequency at which the
output level drops 3dB relative to that
when f = 100kHz is set.
Measure the R, G, B, AC voltage.
Measure the R, G, B, AC voltage.
Measure the G AC voltage.
LA7688B
Test method
CONTRAST
4V
4V
4V
4V
5V
0V
4V
4V
4V
4V
BRIGHT VR
2.5V
2.5V
2.5V
2.5V
2.5V
2.5V
2.5V
2.5V
2.5V
2.5V
No.0077-16/20
Variable
BLK IN
2V
2V
2V
2V
2V
2V
2V
0V
0V