Here a statement about the issue "binary vs analog" readout:

The following advantages and disadvantages of binary front-end electronics were mentioned by Helmut Spieler (an advocate of the binary solution) during the ATLAS SCT Electronics review meeting of Dec 3 1995:

Advantages:

• reduced dynamic linearity required (only up to threshold) -> substantial savings in power and chip area
• pipeline design is greatly simplified since it is completely digital) -> small chip area

Drawback vs. analog readout:

• 10-20% theoretical noise penalty because of neighbour noise cannot be reduced by exploiting anti-correlation (additional circuit complexity in sparsified system).
• Perhaps less diagnostic capability than with analog readout, but measurements show this can be backed up.