video products

Hi Zanzibar,

1. LMK03000 (3 performance grades) can generate 74.25 MHz and 27 MHz by locking the VCO to 1188 MHz.
2. LMK03000 cannot generate 74.25/1.001 MHz and 27 MHz simultaneously.
3. LMH1981 analog video sync separator + LMH1982/83 clock gens can be used as a genlock clock solution.
4. LMK04800 family can be used for video clock cleaning, clock generation, and distribution/fanout (up to 14 differential outputs).  However, this may be overkill in terms of features/functionality.

Regards,
Alan

Hi there,

We also would like to  design a new video board, and have the following specifications :

1. We use a LMH0031 which generate in HD a pixel clock of 74.25 or 74.25/1.001 .

• What is the best solution to generate a stable, low jitter 27Mhz from this HD pixel clock?
• What is the best solution to clean the of this HD pixel clock (without using an  external VCXO on LMH0031)?

2. We would like to generate simulaneously a low jitter (74.25 or 74.25/1.001) and 27MHz, with a frequency control of +-100ppm on both generated frequency, with a step at least of +-1ppm. What is the best solution?

Thanks in advance.

Regards,

Thierry

Hi,

Is it possible to have some answers from the questions above? or should I post another message with another subject?

Thanks in advance.

Thierry

One solution which would generate simultaneously the 27MHz, 74.25 and 74.18MHz clocks, all locked to the SDI input to the LMH0031 would be to take the H,V and F sync signals from the LMH0031 multifunction I/O port (default Bits 0, 1 and 2), and to provide those as a reference to an LMH1983.  The LMH1983 would lock to the HVand F and would provide video and audio clocks locked to this reference.   If you wanted to unlock the video clocks from the reference, then you could do so, and control the frequencies of the LMH1983 manually, although the three video frequencies will always remain locked to one another.

Mark