NCE3400X — N-Channel 30V/5.1A Low-Gate-Charge Power MOSFET (SOT-23)

What Are the Technical Specifications of NCE3400X?

R_DS(on) at each gate drive level. The 2.5V performance (55mΩ max) works for 3.3V logic direct drive. At 4.5V you drop to 39mΩ. At 10V you hit 24mΩ typical.

If your gate drive is 3.3V, budget for higher conduction losses than a 5V or 10V design — the R_DS(on) nearly doubles compared to 10V drive.

Bar width = max R_DS(on) relative to 55mΩ. The jump from 2.5V to 4.5V gets you ~30% lower resistance. Going to 10V buys another ~15% — diminishing returns after 4.5V.

NCE3400X vs NCE3400 — which one for your design? The X gives up 0.7A of current (5.1A vs 5.8A) but saves 7% on gate charge and 28% on input capacitance. For PWM above 20kHz, pick the X. For a load switch, pick the standard part.

Left bar = NCE3400X, right bar (muted) = NCE3400. Lower is better for Q_G and C_ISS; higher is better for I_D. The X is the switching-optimised variant.

SOT-23 pinout — N-channel, source to ground. Pin 1 is Gate, Pin 2 is Source (to GND), Pin 3 is Drain (to load). Standard low-side switching configuration. The pinout is identical to NCE3400 — same footprint, same orientation.

When Should You Use (and NOT Use) the NCE3400X?

✓ Use the NCE3400X when:

• You're switching at 20kHz or above. The 9.3nC gate charge and 595pF input capacitance are the X's main advantage. Lower gate charge = less energy wasted charging and discharging the gate on every cycle.
• Your load is 4A or less continuous. At 5.1A you're at the limit. Derate to 4A for thermal margin on a typical 2-layer board with minimal copper pour.
• You're driving the gate directly from a 3.3V MCU GPIO. The tighter V_GS(th) spec (1.2V max) means less variation in turn-on behaviour. At 3.3V drive you get R_DS(on) somewhere between the 2.5V and 4.5V curves.
• You need tighter lot-to-lot consistency. The X variant's electrical specs are published with narrower spreads than the standard NCE3400. If your production test limits are tight, the X gives you less variation to budget for.

✗ Don't use the NCE3400X when:

• You need every amp of current headroom. The standard NCE3400 gives you 5.8A vs 5.1A. If your load pulls 4.5A continuous, take the standard part.
• Your switching frequency is under 1kHz. At low frequencies, gate charge doesn't matter. Conduction losses dominate. The standard NCE3400's lower R_DS(on) (41mΩ max at 10V vs 33mΩ) actually wins here.
• You need ESD protection on the gate. The NCE3400X does not have built-in gate ESD protection. If your design needs it, use the NCE3400E variant instead — same specs plus ESD diodes.
• You're cost-optimising a high-volume design. The standard NCE3400 moves in higher volumes and is typically a few cents cheaper. If you don't need the switching optimisation, don't pay for it.

What Are the Alternatives to NCE3400X?

The NCE3400X sits in a sweet spot: lower gate charge than the standard NCE3400, lower cost than the Infineon IRLML6344, and better switching performance than the AO3400A. If your design switches above 20kHz and pulls under 4A, this is the one.

NCE3400X vs NCE3400: How to Choose

Both parts share the same SOT-23 footprint, the same 30V rating, and the same pinout. So when do you pick one over the other?

Pick NCE3400X if switching loss dominates. At 50kHz PWM with a 3.3V gate drive, the X's 9.3nC gate charge vs the standard's 10nC saves ~7% on gate drive energy per cycle. The 595pF vs 825pF input capacitance means faster rise and fall times. These differences compound at higher frequencies.

Pick NCE3400 if conduction loss dominates. In a load switch, I²R is all that matters. The standard part's lower R_DS(on) at 10V (22mΩ typ vs 24mΩ typ) and higher current (5.8A vs 5.1A) give more margin.

The 0.7A difference: at 5A load, that's running at 86% of rating vs 98%. One leaves room for thermal drift; the other doesn't.

If you're not sure, default to NCE3400. The standard part is more forgiving of thermal design, higher volume, and slightly cheaper. Only reach for the X if you have a specific reason to optimise for switching speed.

Why Buy NCE3400X from ICMASS?

We stock both the X and standard variants. NCE3400, NCE3400X, and NCE3400E. If you're unsure which one fits your design, we can help you compare switching loss vs conduction loss for your specific operating point.

Gate charge verification available. The X variant's value proposition is its lower gate charge. If your design depends on that 9.3nC number, we can sample-test your lot to confirm the spec before shipping.

Ships alongside complementary parts. Need NCE2309 for the high side and NCE3400X for the low side? One PO, one shipment.

Frequently Asked Questions

Q1: What's the difference between NCE3400X and NCE3400?

A: The X variant prioritises switching speed over current capacity. NCE3400X: 5.1A, 9.3nC Q_G, 595pF C_ISS. NCE3400: 5.8A, 10nC Q_G, 825pF C_ISS. Same 30V, same SOT-23, same pinout. Pick X for PWM above 20kHz; pick standard for load switching.

Q2: Can I drop NCE3400X into an NCE3400 footprint?

A: Yes, same SOT-23 pinout and footprint. No layout changes. Verify your load current is under 5.1A. If your existing design runs the NCE3400 at 5.5A, the X variant will be overstressed.

Q3: Does NCE3400X have gate ESD protection?

A: No. The standard NCE3400X does not include gate ESD diodes. If your design needs ESD protection, use the NCE3400E variant which adds protection diodes while keeping similar electrical specs.

Q4: Can I drive NCE3400X directly from a 3.3V MCU GPIO?

A: Yes, but check your current. At V_GS=3.3V, R_DS(on) is between the 2.5V (55mΩ) and 4.5V (39mΩ) curves. Estimate ~48mΩ. At 3A load, that's ~0.43W conduction loss. Add a small gate resistor (100Ω) to limit the GPIO's peak current while charging the 595pF gate.

Q5: What's the NCE3400E variant?

A: Same silicon as NCE3400X with added ESD protection on the gate. Slightly higher current rating (5.3A) and slightly lower gate charge (9.1nC). The E variant is the best all-rounder in the 3400 family — ESD protection plus low gate charge.

Q6: Can NCE3400X replace an AO3400A?

A: Yes, drop-in compatible. Same 30V, same SOT-23. The NCE3400X has lower gate charge (9.3nC vs ~10nC) and lower input capacitance. The AO3400A has a slightly higher current rating (5.7A). For most designs, the swap is transparent.

Q7: What's the maximum PWM frequency for NCE3400X?

A: Practical limit around 100–200kHz. At 9.3nC gate charge, switching losses at 100kHz are manageable with reasonable gate drive. Above 200kHz, transition losses dominate and you should look at a part with even lower gate charge or a dedicated gate driver.