ADV7441A Power Supply architecture

The ADV7441A has 6 power domains: 4 @ 1.8V and 2 @ 3.3V. The ADV7441A Video Input Module design uses a separate LDO for each domain, with an EMC filter included on each. Customers would like to combine supplies where possible to reduce cost,... Please provide some guidance on what supplies can be combined, the need for the EMC filters and other strict design rules that should be followed for the power supplies.

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    •  Analog Employees 
    on Apr 21, 2010 11:13 PM

    I can tell you that I used a single 1.8V supply and single 3.3V supply and isolated each power domain from the primary voltage with an EMC filter.  It worked but I wasn't pushing the part very hard.  The recommendations in the data sheet and hardware manual are what they are... design to save cost is never without compromise.

    The PLL supply might warrant it's own... something like the ADP120 is pretty cheap and simple. We did have issues with our audio PLL locking and I think it was power supply related.

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  • 0
    •  Analog Employees 
    on Apr 21, 2010 11:13 PM

    I can tell you that I used a single 1.8V supply and single 3.3V supply and isolated each power domain from the primary voltage with an EMC filter.  It worked but I wasn't pushing the part very hard.  The recommendations in the data sheet and hardware manual are what they are... design to save cost is never without compromise.

    The PLL supply might warrant it's own... something like the ADP120 is pretty cheap and simple. We did have issues with our audio PLL locking and I think it was power supply related.

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