I am using AD9467 in my application. I want to calculate -1 dBFS input power. What resistance value should I use to convert 2.5V p-p voltage to power as per datasheet ?

I am using AD9467 in my application. I want to calculate -1 dBFS input power. What resistance value should I use to convert 2.5V p-p voltage to power as per datasheet ?

Hi,

The ADC always faithfully converts the voltage that is present at its inputs. As such, it doesnt really depend on any "power" number. You can look at this article for insights

Who Ate My dBs? | Analog Devices

Differential Signals Allow Input Swing to Exceed Supply Voltage | Analog Devices

So if you are trying to convert the 2.5Vpp to a power level, I would

- convert it to a single ended signal (which would be 2.5Vpp if the balun is a 1:1 ideal balun)

- convert this voltage to power referenced to 50Ohms (which is around +12dBm)

This conversion does not take into account the insertion loss that the signal incurs along the front end network.

Thanks

Umesh

Hi,

The ADC always faithfully converts the voltage that is present at its inputs. As such, it doesnt really depend on any "power" number. You can look at this article for insights

Who Ate My dBs? | Analog Devices

Differential Signals Allow Input Swing to Exceed Supply Voltage | Analog Devices

So if you are trying to convert the 2.5Vpp to a power level, I would

- convert it to a single ended signal (which would be 2.5Vpp if the balun is a 1:1 ideal balun)

- convert this voltage to power referenced to 50Ohms (which is around +12dBm)

This conversion does not take into account the insertion loss that the signal incurs along the front end network.

Thanks

Umesh