AFE5832LP: For a 128-channel system using four AFE5832 devices, should the CW current outputs be summed before the I/V resistor, or should each device have its own I/V res

Part Number: AFE5832LP
Other Parts Discussed in Thread: AFE5832, THS4131

For a 128-channel system using four AFE5832 devices, should the CW current outputs be summed before the I/V resistor, or should each device have its own I/V resistor followed by voltage summing?

We are using four AFE5832 devices to build a 128-channel CW Doppler system. The AFE5832 EVM shows that each CW output (CW_IP/QP_OUTP/N) uses a 4.99-Ω resistor to VfQ/VfI for current-to-voltage (I/V) conversion, followed by the THS4131 amplifier.

For a multi-device implementation, what is the recommended connection method?

Can the CW current outputs from four AFE5832 devices (for example, all CW_IP_OUTP together and all CW_IP_OUTN together) be directly connected together to form one current-summing node, followed by a single pair of I/V conversion resistors (4.99 Ω) and one THS4131?

Or should each AFE5832 perform its own I/V conversion first, with the resulting voltage signals summed afterward?