Updated
Quick answer: Remote SENSE can reduce steady-state voltage error caused by power leads. Whether it is required depends on loop resistance and the DUT voltage tolerance—not a universal 10A threshold or a guarantee of sub-millivolt accuracy.
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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.
Turn the voltage tolerance into a purchase requirement
There is no universal current threshold above which local sensing becomes unusable. A short low-resistance connection may meet the voltage budget at high current; a smaller current can cause unacceptable error on a tight-tolerance low-voltage rail. Compare calculated and measured drop with the DUT’s permitted error.
| Procurement question | Evidence to request |
|---|---|
| What does the DUT require? | Allowed voltage range and actual load waveform. |
| What does SENSE compensate? | Maximum permitted drop and terminal-voltage limits. |
| How are faults handled? | Open/reversed-sense behaviour and protection configuration. |
| How is performance accepted? | DUT-side steady-state and transient measurements. |
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 |
|---|---|
| Error budget | Calculate I × total loop resistance at the intended current. |
| DUT tolerance | Compare the resulting drop with the permitted rail error. |
| Sense capability | Confirm compensation range and open/reversed-sense behaviour. |
| Acceptance | Measure regulation and transients at the DUT terminals. |