I am using the TGA2237-SM for the TX side in a front end design. I am trying to figure out an analog method for doing the bias up and bias down procedures.
- Set gate to Vg=-5V
- Increase Vg till Id=360mA (drain current), Vg~-2.6V
- Apply RF
- Turn off RF
- Decrease Vg to -5V
- Turn off supplies
I was thinking of using a current sense amplifier similar to the LT6106, where my load would be the drain of my RF amp and the Vout of the LT6106 would be the gate of the RF amp. See image below.
I need the Vout to start at a voltage and then increase based on the load current increase. This sort of analog design is not my wheelhouse, but I feel like this should be easy, but something is eluding me.