A
[email protected]
- Jan 1, 1970
- 0
I'm using an ICS AC9173-01 to recover a video dot clock. The datasheet
offers no insights as to what's in there and what kind of power supply
it wants. I have 5mV p-p noise as measured across the device's power
pins. Now that's pretty good for a purely digital supply, but I think
it's not good for a VCO that can cover 10-75MHz off a 5V supply.
Supposing that a 0-5V swing covers 65MHz (guessing that the VCO uses
0-5V), that means 1mV corresponds to a 13KHz variation. So the 5mV
noise could modulate the VCO by +\- 33KHz from the center frequency.
Anyone have any clues how a VCO is made inside an IC and how sensitive
they are to power supply noise? I'm thinking of regulating a local 5V
just for this guy, what's a good linear regulator for the job? LT1963
comes to mind, any others?
BTW, ICS/IDT is the worst company I've ever dealt with to try and get
the application notes they suggest you read in the datasheet...
offers no insights as to what's in there and what kind of power supply
it wants. I have 5mV p-p noise as measured across the device's power
pins. Now that's pretty good for a purely digital supply, but I think
it's not good for a VCO that can cover 10-75MHz off a 5V supply.
Supposing that a 0-5V swing covers 65MHz (guessing that the VCO uses
0-5V), that means 1mV corresponds to a 13KHz variation. So the 5mV
noise could modulate the VCO by +\- 33KHz from the center frequency.
Anyone have any clues how a VCO is made inside an IC and how sensitive
they are to power supply noise? I'm thinking of regulating a local 5V
just for this guy, what's a good linear regulator for the job? LT1963
comes to mind, any others?
BTW, ICS/IDT is the worst company I've ever dealt with to try and get
the application notes they suggest you read in the datasheet...