la7688b Sanyo Semiconductor Corporation, la7688b Datasheet - Page 17

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

Deflection block Input signals and test conditions
Set up the following conditions unless otherwise specified for each test item.
(VIF, SIF blocks : No signal)
1. EXT VIDEO IN : • Horizontal ⋅ vertical composite signal (1Vp-p, same as for video block, chroma block)
2. SW conditions : All SW's turned off unless otherwise specified
3. V CC , I CC conditions : V CC = 7.8V, I CC = 12mA
[Deflection block]
Vertical free-running period
Vertical sync maximum
period
Vertical sync minimum
period
Vertical blanking pulse peak
value
Vertical blanking pulse
width
Vertical output pulse width
(I-14A)
Parameter
• Horizontal sync signal only (0.5Vp-p, pulse width 4.7µs)
• Open
TV free
50
TV free
60
TV max50
TV max60
TV min50
TV min60
VHVBL
PW BLK50
PW BLK60
PWVOUT
Symbol
Z-20B
Z-20B
Z-20B
Z-20B
Z-20B
O-25
Z-20B
O-25
O-32
O-32
O-32
Z-20B
point
Test
I-14A :
No signal
I-14A :
No signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal ⋅
vertical sync
signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal ⋅
vertical sync
signal
signal
Input
LA7688B
With Z-21 connected to GND, measure the vertical
output period at Z-20B and calculate the ratio to the
horizontal period.
With 7.8V applied to Z-21, measure the vertical
output period and calculate the ratio to the
horizontal period.
With Z-21 connected to GND, measure the vertical
output period at Z-20B and calculate the ratio to the
horizontal period.
With 7.8V applied to Z-21, measure the vertical
output period and calculate the ratio to the
horizontal period.
Apply 8.5V and 0V to Z-27B and Z-21,
respectively. Turn off SW20 and make adjustments
so that the resistance between O-20 and GND
becomes 4.7k Ω and then turn on SW20.
Calculate the ratio between the vertical output
period at Z-20B and the horizontal output period at
O-25.
Apply 8.5V and 7.8V to Z-27B and Z-21,
respectively.
Make measurements in the same manner as for
TV min 50.
Measure the vertical blanking pulse peak value in
the video output at O-32.
(GND is assumed to be 0V.)
With Z-21 connected to GND, measure the vertical
blanking pulse width in the video output at O-32
and calculate the ratio to the horizontal period.
With 7.8V applied to Z-21, measure the vertical
blanking pulse width in the video output at O-32
and calculate the ratio to the horizontal period.
Measure the vertical output width at Z-20B and
calculate the ratio to the horizontal period.
3V
0V
Test method
PWOUT
Continued on next page.
SW20
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
↓
↓
No.0077-17/20
SW25
B
B
B
B
B
B
B
B
B
B