la7688b Sanyo Semiconductor Corporation, la7688b Datasheet - Page 18
la7688b
Manufacturer Part Number
la7688b
Description
Pal/ntsc Color Television-use Single-chip Lsi
Manufacturer
Sanyo Semiconductor Corporation
Datasheet
1.LA7688B.pdf
(20 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Continued from preceding page.
Vertical output voltage
Vertical external trigger load
resistance
Vertical automatic sync stop
voltage
Horizontal AFC gate
release voltage
Vertical output pulse start
V CC voltage
Horizontal free-running
frequency deviation
Dependence of horizontal
free-running
frequency on V CC
Horizontal pull-in range
Horizontal output pulse start
V CC voltage
AFC2 FBP peak value
Parameter
V OUT H
V OUT M
V OUT L
R TR
V SAS
V GS
S VV
∆ fH
∆ fHV CC
fHPULL
S HV
FBPH
FBPM
FBPL
Symbol
Z-20B
Z-20B
O-20C
I-20A
Z-22
Z-22
Z-20A
Z-20B
V CC
O-25
O-25
O-25
I-14A
O-25
I CC
Z-26B
point
Test
I-14A :
Horizontal ⋅
vertical sync
signal
I-14A :
Horizontal
sync signal
I-14A :
Horizontal ⋅
vertical sync
signal
I-14A :
Horizontal
sync signal
I-14A :
No signal
(open)
I-14A :
No signal
(open)
I-14A :
No signal
(open)
I-14A :
Horizontal
sync signal
I-14A :
No signal
(open)
I-14A :
Horizontal
sync signal
signal
Input
LA7688B
Measure the voltage for each vertical output at
Z-20B.
Turn on SW20 and set V,VR to a maximum and
then decrease slowly until the vertical output period
becomes 225H.
Turn off SW20 and measure the resistance
between O-20C and GND.
Use the vertical output at Z-20B to synchronize an
oscilloscope and monitor the output waveform at
Z-22.
Connect a DC power supply to I-20A and raise the
voltage slowly until the output waveform becomes
larger.
Measure the voltage at I-20A at that moment.
Connect a DC power supply to I-20A and set it at
0V. Monitor the AFC1 waveform at Z-22 and raise
the supply voltage at Z-20A slowly until the AFC1
waveform for the vertical sync's equivalent pulse
period changes.
Measure the voltage at Z-20A at that moment.
Raise V CC (pins 40, 44, and 45) from 0V slowly
until a pulse signal appears in the vertical output at
Z-20B. Measure V CC at that moment.
Connect a counter to O-25 (horizontal output) to
measure the horizontal free-running frequency.
Calculate the deviation from 15.680kHz.
Connect a DC power supply to I CC (horizontal pin
24 V CC ) and set it at 6.0V. And then measure the
horizontal output frequency at TP14 and calculate
the deviation from the horizontal free-running
frequency.
Monitor the horizontal sync signal and the
horizontal output at O-25 using an oscilloscope
and vary the horizontal sync signal frequency to
measure the pull-in range.
Connect a DC power supply to I CC (horizontal pin
24 V CC ) and raise it from 0V slowly until a pulse
signal appears in the horizontal output at O-25.
Measure the Icc pin voltage at that moment.
Measure the FBP peak value at Z-26B.
V OUT H
0V
0V
FBPL
FBPM
Test method
V OUT L
FBPH
V OUT M
Continued on next page.
SW20
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
↓
No.0077-18/20
SW25
B
B
B
B
B
B
B
B
B