TDA4439 Description
open B/G ground L Ground IF-AGC storage capacitor AGC (tuner control) Tuner AGC take over Polarity switch: open AFC “DOWN” ground AFC “UP” Demodulator circuit AFC circuit AFC output Average capacitor standard L Video output Supply voltage n.c. Circuit Description The following function units are integrated in this circuit bination for video-IF processing:.
TDA4439 Key Features
- Three symmetric, highly stable, gain controlled wide
- Disconnectable AFC generator with push pull band amplifier, quasi galvanic coupling eliminates current output feed back
- High impedance, interference free controlled voltage
- Video carrier controlled demodulator of high linearity facilities, best possible AGC time constant with small storage ca
- Polarity switch over for video and AFC-signal
- Controlled discharge circuit for fast gain control
- Video output amplifier with low-pass characteristics, limiter for ultra black and inverter for ultra white
- With VTR operation the video output level is interference according to the ultra white level in B/G, ultra black level i