Dear Sir/Madam,

As for your VGA ADRF6510, I have a question.

What is the output drive current min and max? Also the electrical power value this can drive.

I would like to know what is the min/max drive ability.

"Differential output Impedance" is showed as typ. 20 ohm, and "Max. output swing" is showed as 2Vp-p on your datahseet.

So how should I think this?

In the case of 20 ohm fixed,,,,,

If the output is 1V DC, the current is 1/20 A.

So the power is 1/20 W.

If the output is 2Vp-p sinwave, the current is 0.7/20 A.

So the power is (0.7x0.7)/20 W.

If the above is correct, then how should I the dispersion min-max of "Differential output Impedance"? Maybe you cannot guarantee this due to that it is not put on your datasheet only typ value 20 ohm.

Thanks Kaos

Hi Kaos,

Usually we specify it as

max power deliveredto the load. So if the output signal is swinging at 2 Vpp max into a load of 1k Ohms, then the max power would be Power = (2 Vpp/ (2*sqrt(2)))^2/1k Ohms = (.7 Vrms)^2/1kOhms = 0.5 mW.So then max rms current into a 1k Ohm load would be 0.7 Vrms/1k Ohms = 700 uA, but this probably isn't the absolute maximum current of the device as it has probably hit is voltage limit, not the current limit. Having said that, the ADRF6510 was designed to drive relatively high load impedances. For example, 400 Ohm differential or higher.

Hope this helps,

Joel