NCE3010S vs NCE3015S vs NCE3018AS: Side-by-Side Comparison

The one-line summary: same class, same pinout, three design stops — the 10A entry buys cost, the 15A middle buys the best 5V-logic row, and the 18A top buys pulse current and avalanche margin. R_DS(on) at 10V stops improving after the middle die.

Key Differences

The 10V R_DS(on) plateau — the middle die is where the improvement stops

R_DS(on) max at 10V drops from 12mΩ (10A) to 7mΩ (15A) — a 42% cut in conduction loss. From 15A to 18A it stays at 7mΩ: the top die buys no additional conduction performance at 10V drive.

The consequence: at any current the 15A and 18A parts run identically hot. Stepping up past 15A only pays when the extra current, pulse, or avalanche ratings are actually exercised.

Why would anyone buy the top die, then? Because of what happens off the datasheet's first page — the events.

The 4.5V drive row flips the ranking

At 4.5V drive the order reverses: 16mΩ (10A) vs 9.5mΩ (15A) vs 10mΩ (18A). The middle die is the family's 5V-logic champion, and the top die — despite the biggest die — is not.

Threshold voltages tell the same story in reverse: V_GS(th) max falls from 3.0V to 2.4V to 1.4V across the family, so the top die has the best 3.3V margin. But none of the three spec R_DS(on) below 4.5V — no margin story changes that.

Here's the thing to weigh: does the 4.5V row make the middle die the best buy overall? Not for stall-prone loads — that decision belongs to the pulse and avalanche numbers.

Pulse, avalanche, and gate charge — what the bigger dies actually buy

I_DM climbs 50A → 60A → 72A; E_AS goes from not published → 120mJ → 204mJ with test conditions. Gate charge climbs 32.5 → 32.3 → 41nC: the top die charges 27% more gate per cycle.

The pattern: each die step trades driver burden for pulse and avalanche headroom. The 10A entry keeps gate charge low; the 18A top spends 41nC to buy the events that break smaller parts.

Why does the gate-charge tax matter more than it looks? Because every switching cycle pays it, at whatever frequency the board runs.

Package thermal parity — all three live in the same 150-mil envelope

P_D differs (2.5W / 3.5W / 3W) and so does R_θJA (50 / 36 / 42°C/W), but all three numbers describe the same physics: a 150-mil SO-8 with the PCB as its only heatsink.

All three thermal rows carry the short-duration FR4 footnote in their datasheets. None of them carries its headline current on a skimpy copper pour — ≥100mm² drain copper is the rated operating condition for the whole family.

When to Choose the NCE3010S

• Loads under ~8-10A sustained — where 12mΩ vs 7mΩ is a fraction of a watt of difference.
• Cost-first boards — smallest die, fewest pennies, same package and pinout.
• Gate-charge-sensitive, high-frequency switching — 32.5nC is the family's leanest driver load alongside the middle die.
• 10V or 5V gate rails both work — its 4.5V row (16mΩ) is worst-in-family but specified.

When to Choose the NCE3015S

• 5V-logic drive with loads from 8A to 15A — the 9.5mΩ 4.5V row is the family's best.
• The board wants a drop-in from a 10A socket with headroom — same Q_g, half the R_DS(on) at 10V.
• Stall or unclamped solenoid risk with a budget — E_AS 120mJ published, 100% UIS tested per datasheet.
• Loads at 10-15A where the 18A part would just add gate charge.

When to Choose the NCE3018AS

• Loads past 15A, or hot-plug rails with capacitor inrush — 72A pulse rating.
• Unclamped inductive events where you need a verifiable margin — E_AS 204mJ with full test conditions.
• Parallel-pair output stages past 30A — two parts on shared copper.
• Future headroom: designs likely to grow past 15A without a layout change.

When to Skip All Three

• Raw 24V battery rails. A 24V lead-acid float sits at 28.8V; forum consensus calls a 30V part on a 24V system "asking for problems" — 40V minimum for clean rails, 60V for inductive loads. NCE's 60V SOP-8 line (NCE6008AS-class) is the step.
• 3.3V GPIO direct drive. None of the three spec below 4.5V. Pick a 2.5V-specified part or add a driver.
• Sustained current past ~15A on one part. Two parallel parts, or move to a TO-252/TO-220 power stage.

Frequently Asked Questions

Q1: Can I swap between the three without changing the PCB?

A: Yes — same package, same pinout, different electrical promises. All three are SOP-8 with pins 1-3 Source, 4 Gate, 5-8 Drain. Check two things before the swap: your gate rail (the 4.5V rows differ: 16 / 9.5 / 10mΩ) and your actual load. A 10A socket stepping to the 3015S is the cleanest upgrade in the family.

Q2: The 15A and 18A parts have the same 7mΩ — which do I buy?

A: Buy by stress, not by the bigger number. At identical loads below 15A they run identically; the 15A part drives easier (32.3nC vs 41nC) and wins the 4.5V row. The 18A part is the right buy only when you need 18A, the 72A pulse, or the 204mJ avalanche budget with published conditions.

Q3: Is the 18A top die always the better part?

A: No — the datasheets prove the opposite for 5V-logic boards. The 18A part charges 27% more gate per cycle, has a slightly worse 4.5V row, and costs more. Over-specifying by current rating is the most common selection mistake in this family (from what we see in Shenzhen, 2025–2026) — pick the die your load actually stresses.

Q4: Which one works with 3.3V or 5V logic?

A: 5V logic: the 3015S. 3.3V logic: none of them, by specification. At 5V the 3015S's 9.5mΩ 4.5V row is the family's best. The 3018AS has the lowest threshold (1.4V max) so it starts conducting earliest — but none of the three guarantee R_DS(on) below 4.5V, and forum guidance is consistent: a 3.3V rail needs a 2.5V-specified part or a gate driver.

Q5: Which one survives a motor stall without a clamp?

A: Only the two that publish an E_AS number — 3015S at 120mJ, 3018AS at 204mJ. The 3018AS additionally publishes its test conditions (L = 0.5mH, V_DD 15V), so its margin can be checked against your own ½LI² stall energy. The 10A entry publishes no avalanche rating — don't run it unclamped into inductive loads.

Q6: What continuous current is realistic on a real board?

A: Roughly 5-7A, 8-12A, and 10-14A for the three parts, with ≥100mm² drain copper. The headline ratings (10/15/18A at 25°C) derate to 7/10.6/12.7A at 100°C, and the package envelopes (2.5/3.5/3W) bind first. Fairchild's AN-1032 documents how SO-8 continuous capability collapses without copper.

Q7: Is 30V enough for a 24V system?

A: No for raw battery rails — step past this family. A 24V lead-acid float sits at 28.8V, leaving under 1.2V of headroom at 30V. Forum consensus: 30V on 24V is too tight; 40V minimum for clean regulated rails, 60V for inductive or automotive loads. NCE's own 60V SOP-8 line shares this pinout.

Q8: Can I parallel different dies of the family?

A: Not recommended — parallel like-for-like. Different R_DS(on) dies (12 vs 7mΩ) share current unevenly and heat differently. Two 3015S or two 3018AS on shared drain copper with equal gate traces is the sanctioned way to push past one part's envelope.