I am attempting to remove the DC offset from the 1 kHz, ± 2.5 V, AC square wave output pins of an ADS1261 (http://www.ti.com/lit/ds/symlink/ads1261.pdf). However, when measured on the oscilloscope (and modelled in LTSpice), the average DC value is approximately 2 mV.
I have modelled a passive RC high pass filter in LTSpice (similar to Changing a Signal's DC Offset), however, I have found that instead of maintaining the ± 2.5 V and removing the offset, I get 0 - 5 V output instead.
How can I remove the DC offset/average while maintaining the ± 2.5 V square wave?
Result with C1 as 15 nF
Result with C1 as 100 uF