![5. Circuit description](/images/new-backgrounds/105054/10505443x1.webp)
17” CDT Color Monitor | 107B7 |
5. Circuit description
Micro Controller
The micro controller(IC101) core is a 80C51 type. The micro clock frequency of 12 Mhz is derived from the Xtal oscillator, which is running at 48MHz. The DDC interface is suitable to handle DDC2 by a modified hardware
The SAA4849P provides sync. Processing with full auto sync. Capability, a flexible SMPS block and an extensive set of geometry control facilities. Further the IC generates the drive waveforms for DC coupled vertical boosters to the TDA4863A.
H/V sync signals processor
The functions of the sync processor include polarity detection,
Reset Circuit(pin23)
There are three ways possible to invoke a reset and initialize the SAA4849 micro controller part:
Via
Via watchdog timer overflow(only micro controller reset)
Via deflection reset after start up(only micro controller reset)
The reset pin(pin23) is connected to a Schmitt trigger for nose reduction. A reset is accomplished by holding the Reset pin HIGH.
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5V | 22U | ||
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R153
2.7K
RST Pin23
C102
0.1UF
22