TEA2029 STMICROELECTRONICS [STMicroelectronics], TEA2029 Datasheet - Page 38

• Manufacturer Part Number: TEA2029
• Description: APPLICATION NOTE
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

TEA2028 - TEA2029 APPLICATION NOTE
Figure 73
Figure 74
VII.5 - Frame Blanking Safety
- During trace : I
- During flyback : I
In the absence of flyback detection or if the flyback
interval is longer than the blanking time, the sand-
castle low level remains constant at 2.5V so as to
38/46
Horizontal Flyback
S3
Switching Voltage
(Horizontal Logic)
Phase Limitation
Safety & On/Off
S3
< I
V
> I
IN
4
4
40 s
HORIZONTAL
FLYBACK
FRAME
OUTPUT
HORIZONTAL
SAWTOOTH
Transconductance
2
1
T3 is blocked.
T3 conducts.
Amplifier
V
I
T1
I
I
S3
V
S1
V
&
13
0
4
1
I
C
150pF
S2
S
R
V
B
I
I
Q
Q
4
3.5V
T3
protect the picture tube in the absence of frame
scanning.
- ”IF” signal is delivered by Frame Error Amplifier
- IF is high during the Frame Flyback interval
(see Frame phase modulator figure)
Horizontal
Sawtooth
V
CC
Safety Frame
Logic to Super
Sand Castle I.F.
40 s max.
64 s
6 s
3.5V
4
t
OUT
Frame
Output
t
t