Quick answer: A 60A current through a 5mΩ total force-loop resistance produces a calculated 0.30V drop. On a nominal 3.30V rail that leaves 3.00V at the DUT. This is an illustrative calculation, not a measured customer outcome or a guaranteed failure threshold.
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What lead resistance changes
With local sensing, the supply regulates near its output terminals. Current through both force leads and their connections creates a load-side drop. Measure total loop resistance or compare source and DUT voltages under load rather than assigning a cable resistance from its gauge alone.
Illustrative 60A calculation
Example assumptions: load current 60A, total force-loop resistance 5mΩ and a 3.30V terminal setpoint. The calculated drop is 60A × 0.005Ω = 0.30V, leaving 3.00V at the DUT. The drop is about 9.1% of 3.30V. These numbers are an engineering illustration, not a customer measurement.
If a compatible remote-sense loop regulates 3.30V at the DUT under the same steady-state conditions, the supply terminals would need about 3.60V. This requires sufficient voltage headroom and allowed compensation range. Cable heating remains I²R = 60² × 0.005 = 18W in this example; feedback compensation does not remove that loss.
What Remote SENSE can and cannot do
Separate high-impedance sense leads provide load-side voltage feedback while the force leads carry output current. Feedback can reduce steady-state cable-drop error within the specified compensation range. Final accuracy still depends on the supply, connections and measurement method. Dynamic rail behaviour also depends on bandwidth, cable inductance, load changes and permitted local decoupling.
Separate an electrical hypothesis from a proven fault
A supply-rail error can affect DUT behaviour, but the device’s specifications and measured results determine whether it causes resets or RF degradation. Record rail voltage during the actual test waveform and compare it with the module’s tolerance. Check supply dynamics, connectors and the DUT before attributing every validation failure to cable loss.
Record a reproducible before/after test
- Keep the DUT, workload, fixture and measurement bandwidth the same.
- Record force-terminal and DUT-side voltage, current and relevant temperature.
- Implement approved wiring or compensation changes, then repeat the measurement.
- Compare actual RF metrics and device status; report the observed change rather than an assumed improvement.
Project cost depends on your own records
Avoid assigning a universal dollar saving to a 0.3V drop. If the fault causes rework, document engineering time, repeat bookings and schedule impact from the project’s records. The calculation above does not demonstrate a $50,000 loss or a guaranteed return on investment.
Evaluate the eTM-30200C configuration
The eTM-30200C product data lists 0–30V, 0–200A and 6000W. For a SENSE-equipped test setup, confirm the ordered option, compensation limits, supported communication and wiring instructions. A voltage/current rating alone does not verify transient recovery, sub-millivolt accuracy or open-sense protection.
Practical checks
| Check | What to verify |
|---|---|
| Voltage budget | Compare expected drop with the device’s documented tolerance. |
| Evidence | Measure the rail at the DUT during the real waveform. |
| Root cause | Separate cable loss from supply dynamics and DUT behaviour. |
| Retest | Record before/after results under matching conditions. |
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