ADV7391 High Drive Compensation Pin Connection

Dear Analog Devices Team

We are designing a board which uses ADV7391BCPZ Video Encoder and ADA4433-1BCPZ-R2 SD Video filter amplifier.

Below are the few observation :

  1. Application circuit example in ADV7391BCPZ datasheet recommends to connect the RSET to 510Ohm and COMP pin to 2.2nF which will be pulled to VAA ( 3.3V ) for full drive mode.
  2. In the development board schematics also you have made use of full drive option by connecting COMP to VAA and keeping RSET to 510Ohm.
  3. For the low drive operation of ADV7391BCPZ the COMP pin status is not mentioned in the datasheet. I.e whether it should be connected to VAA or Ground.
  4. When we referred ADA4433 datasheets Application circuit ( Page No. 21 of 28, Figure 53) for low drive operation the COMP pin has been connected to Ground through 2.2nF capacitor.
  5. We have set voltage at IN- pin of ADA4433-1 as 0.5V using a recommended biasing network and output to 1Vp-p.
  6. So, In high drive we connect COMP to VAA using 2.2nF capacitor and in low drive mode we connect COMP to Ground using 2.2nF capacitor ?? Is my understanding correct ?
  7. Please mention the RSET and COMP pin status in High Drive and Low drive mode.

With Regards

Bhanuprakash Nayak

Member Technical-Hardware