twicking manually each amplifier method question

[yefj]

Hello, i have a QPA2575 amplifier shown bellow , there are two connections of Vd and two connections of Vg .
Vg_top and Vg buttom are connected together on the same voltage,so id Vd.
I need to tune this amplifier by controlling the bias point ,so we get quecent current of
I read about a method where we ned to connect a potentimeter in parralel to VD and connect it to ground and measure the current .
1.what potentiometer do you reccoment to use for this purpose?
2.looking at the layout ,where do you reccomend me to put the potentiometer so i will be able to measure the current going into the amplifier?
Thanks.

QPA2575 - Qorvo

www.qorvo.com

 

[BigBoss]

Why don't you look at Power Supply's Ammeter ??

 

[yefj]

Why don't you look at Power Supply's Ammeter ??

Hello Bigboss,because i have 5 such amplifiers in parralel,i need to measure each quecent current personally.
the power supply will give me the total.

 

[FvM]

Bias-up procedure is described in datasheet, due to type variations, it has to be performed for each amplifier separately. In a multi amplifier configuration, you need separate adjustable, low impedance gate bias supplies.

I don't see how a potentiometer can be used to measure drain current. I would use e.g. low ohmic (some 10 milliohm) shunt.

 

[vfone]

According to the datasheet the current measurements should be pulsed.
Now there are many relative cheap power supplies that can do very accurate pulsed current measurements, which anyway, will be more accurate than a shunt method.