Since my CVBS signal is biased 5V and it is 2Vpp overall voltage is approximately 5-7V. I just checked the datasheet of LM1881 which states that for Vcc=5V Input can 3Vpp. So I AC coupled the input and buffered then send to lm1881. Now lm1881 triggers correctly.
However, as a buffer I use pnp follower configuration, output of my buffer seems noisy, this causes lm1881 to trigger wrong sometimes.
I want to use dedicated buffer (opamp) for cvbs.
I have only "MAX457CPA+"or "LMH6704MA" as a buffer. I have never used one before which one do you suggest to use?
Unfortunately, I don't have LM6171 at the moment.