 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
NTE7133 Datasheet(PDF) 6 Page - NTE Electronics |
|
||||||||||||||||||||||||||||||
NTE7133 Datasheet(HTML) 6 Page - NTE Electronics |
|
|
6 / 7 page 
Functional Description (Cont’d): PLL2 Phase Detector This pahse detector is similar to the PLL1 phase detector. Line flyback signals (Pin2) are compared with a fixed point of the oscillator sawtooth voltage. Delays in the horizontal deflection circuit are com- pensated by adjusting the phase relationship between horizontal sync and horizontal output pulses. A certain amount of phase adjustment is possible by injecting a DC current froma an external source into the PLL2 filter capacitor on Pin20. Horizontal Driver This open–collector output stage (Pin3) can directly drive an external driver transistor. The saturation voltage is 300mV at 20mA. To protect the line deflection transistor, the horizontal output stage does not conduct at VP < 6.4V (Pin1). Vertical Oscillator and Amplitude Control This stage is designed for fast stabilization of the vertical amplitude after changes in sync conditions. The free–running frequency fo is determined by the values of RVOS and CVOS. The recommended values should be altered marginally only to preserve the excellent linearity and noise performance. The vertical drive currents I5 and I6 are in relation to the value of RVOS. Therefore, the oscillator fre- quency must be determined only by CVOS on Pin16. fo = 1 10.8 x RVOS x CVOS To acheive a stabilized amplitude the free–running frequency fo (without adjustment) must be lower than the lowest occurring sync frequency. The contributions shown in Table 1 can be assumed. Table 1. Calculation of fo Total Spread Contributing Elements % Minimum Frequency Offset Between fo and the Lowest Trigger Frequency 10 Spread of IC ±3 Spread of R (22k Ω) ±1 Spread of C (0.1 µF) ±5 Total 19 Results for 50 to 110Hz application: fo = 50Hz 1.19 = 42Hz Table 2. VGA Modes Mode Horizontal/Vertical Sync Polarity Horizontal Frequency (kHz) Vertical Frequency (Hz) Number of Active Lines Output Mode Pin7 1 +/– 31.45 70 350 LOW 2 –/+ 31.45 70 400 LOW 3 –/– 31.45 60 480 LOW 4 +/+ Fixed by External Circuitry – – HIGH Autosync */* Fixed by External Circuitry – – Forced to GND |
English ▼
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
