la7688b Sanyo Semiconductor Corporation, la7688b Datasheet - Page 12

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

2. The chroma signal which is input from pin 13 (S-CHROMA IN) is assumed to be a PAL chroma signal.
INT/EXT SW block, SAB block, VIDEO SW block, FILTER block Input signals and test conditions
Set up the following conditions unless otherwise specified for each test item.
(VIF, SIF blocks : No signal)
1. Input signals
2. S-CHROMA IN (pin 13) : DC5V+Chroma signal
3. VR control position : Contrast VR-4V, sharpness VR-2V, others-control center
4. V CC , I CC conditions : V CC = 7.8V, I CC = 12mA.
[INT/EXT SW block]
AFT EXT gain
INT/EXT
crosstalk (AUDIO)
System SW I-SE
System SW I-P/N
System SW E-P/N
System SW E-SE
Y signal frequency
characteristics (3)
(NTSC MODE)
DC transmission
ratio
Black expansion
threshold
Maximum black
expansion gain
(5) SECAM signal
INT SECA --- INT IN (pin 10) 1Vp-p : SECAM color bar
INT PAL
EXT PAL --- EXT IN (pin 14) 1Vp-p : PAL color bar
EXT SECA --- EXT IN (pin 14) 1Vp-p : SECAM color bar
EXT NT
AUDIO IN --- EXT AUDIOIN (12pin) 1Vrms SIN wave (1kHz)
Parameter
R-Y, B-Y demodulation signal
Parameter
--- INT IN (pin 10) 1Vp-p : PAL color bar
--- EXT IN (pin 14) 1Vp-p : NTSC color bar
BW3
DVAPL
BSTH
Bsmax
Symbol
GAF
THDAF
V 1 TH1
V 1 TH2
V 1 TH3
V 1 TH4
Symbol
O-32
O-32
O-33
O-33
point
Test
O-51
O-51
O-16A
O-39
O-16A
O-39
O-16A
O-39
O-16A
O-39
point
Test
f = variable
100mVp-p
White
100%
black
I-14
I-14
conditions
Input
EXT PAL
I-12
EXT PAL
I-12
INT SECA
INT PAL
EXT PAL
EXT SECA
conditions
Measure the frequency at which the
output level drops by 3dB relative to that
when f = 100kHz is set.
Measure the output pedestal level
variations when a white 100% signal and
a black signal are input.
Set S32 to ”B”.
Connect an oscilloscope to 0-33 and
measure the level of 5IRE expansion
when the RAMP signal APL is changed
for a range from 10% to 90%.
Set S32 to ”B”.
Connect an oscilloscope to 0-33 and
measure the change in the pedestal level
when the RAMP signal APL is changed to
90%.
Input
LA7688B
Test method
Measure the gain difference between input and output.
(f = 400Hz, 500mVrms)
Measure the distortion factor of the output.
(f = 400Hz, 500mVrms)
Check to see that the selected signal is INT-SECAM.
Check to see that the selected signal is INT-PAL.
Check to see that the selected signal is EXT-PAL.
Check to see that the selected signal is EXT-SECAM.
Test method
Contrast
4V
4V
4V
4V
Sharpness
1.8V
2V
2V
2V
No.0077-12/20
V-SW
Pin 1
3.3V
3.3V
1.2V
1.7V
2.6V
3.8V
4.1V
Bright
2.9V
2.5V
2.5V
2.5V
2.5V
0V
5V