ADS8598H: multiple ADS8598H on same parallel bus line

Tool/software:

Dear TI support,

I have connected 8 units of ADS8598H on the same parallel bus line DB[15:0] and using the CS pin to separately transmit the data in parallel mode from the ADS to the microcontroller, the latter placed at one end of the bus line.

In my current design I noticed that the values transmitted from the output pins DB[15:0] of the ADS do not match with the values read by the microcontroller.

After some hardware debugging to rule out PCB damage or firmware readout faults, I am left with the doubt that when connecting so many units in parallel the DB[15:0] on the same bus the output pins may not be strong enough to drive the signal through the bus line, i.e. due to the increased load.  In p. 9 of datasheet, the digital output seems capable to source/sink about 0.1mA. What load should I expect when leaving the CS high and thus the DB[15:0] in high-impedance?

Eventually, do I need to use a bus driver that can source/sink more current on the bus line? Can you recommend an application note or some components to address this issue?

Some additional context:

The bus driver is about 1 m long, with ADS equally spaced and the microcontroller on one end of the bus.

The communication timing and configuration pins have been set up for parallel data read operation so to match fig. 4 of the datasheet and sec. 7.4.2.3.1.

RD pin is clocked at ~3 MHz.

Separate electric test of the PCB bus line and microcontroller exclude any track damage or fault into read operation.

ADS reference are connected as in fig. 64.

Thanks, L.