In our application we will use the ADS54J40 in a DC-coupled way. One thing that we do is setting bit0 of register 0x4F (EN_INPUT_DC_COUPLING) to 1.
The details of what happens by setting this bit are not fully clear to me.
The datasheet description for this control bit: "This bit enables dc coupling between the analog inputs and the driver by changing the internal biasing resistor between the analog inputs and VCM from 600 Ω to 5 kΩ.".
However, we have also received a presentation from TI that states that setting this bit disables the addition of a certain CM voltage compensation of ~100mV (called ΔVCM). Apart from that, the presentation still shows 600Ohm biasing resistors in DC-enabled mode.
My main question: what is the value of the input biasing resistors when EN_INPUT_DC_COUPLING is set: 600Ohm or 5kOhm?
Regards,
Paul
