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 :
it is clear for the COMP and Rset connection on the ADV739X datasheet pin definition:
RSET Controls the amplitudes of the DAC 1, DAC 2, and DAC 3 outputs. For full-drive operation (for example, into a 37.5 Ω load), a 510 Ω resistor must be connected from RSET to AGND. For low-drive operation (for example, into a 300 Ω load), a 4.12 kΩ resistor must be connected from RSET to AGND
COMP Compensation Pin. Connect a 2.2 nF capacitor from COMP to VAA;
The ADV739x contains three DACs. All three DACs can be configured to operate in full-drive mode. Full-drive mode is defined as 34.7 mA full-scale current into a 37.5 Ω load, RL. Full drive is the recommended mode of operation for the DACs.
Alternatively, all three DACs can be configured to operate in low-drive mode. Low-drive mode is defined as 4.33 mA full-scale current into a 300 Ω load, RL.
The ADV739x contains an RSET pin. A resistor connected between the RSET pin and AGND is used to control the full-scale output current and, therefore, the output voltage levels of DAC 1, DAC 2, and DAC 3. For full-drive operation, RSET must have a value of 510 Ω and RL must have a value of 37.5 Ω. For low-drive opera-tion, RSET must have a value of 4.12 kΩ, and RL must have a value of 300 Ω. The resistor connected to the RSET pin should have a 1% tolerance.
The ADV739x contains a compensation pin, COMP. A 2.2 nF compensation capacitor should be connected from the COMP pin to VAA.
Also you can see the reference schematics design on ADV739X datasheet Rev E page 72 and &3, Fig- 93 and 94;
Thanks for you quick reply,
I do agree with your answer but my major concern was regarding ADA4433 application circuit.
I 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.
Why is this done ??
Please find the below link for ADA4432-1/ADA4433-1 component datasheet.
Please refer to figure 53 which uses ADV7391 component, in which COMP pin is connected to ground using 2.2nF capacitor.
Do you see there is a typo in ADA4432-1/ADA4433-1 component datasheet ?
seems there is some mistake for the ADA4433 application circuit, i checked the ADA4432 amd ADA4433 products web, the ADA4433 application circuit should be from the CN0264 as below web link
Circuit Note | CN0264 | A Robust Solution for Transmitting Composite Video with Output Short-to-Battery Protection | Ana…
on the system block, it is same as the ADA4432/4433 datasheet system block, but you downalod the whole design documents and check the schematics, the COMP connection is same as ADV739X datasheet;
EVAL-CN0264-EB1Z-PADSSchematic-Rev0.pdf page 2
Thanks for the clarification.