UT3N06G-AB3-R — 60V 3A N-Channel Power MOSFET (SOT-89) from UTC

What Are the Technical Specifications of UT3N06G-AB3-R?

Key numbers that matter: the 690mW package limit is the spec engineers miss. At 3A through 90mΩ, the die dissipates 0.81W — already over the package budget before you add any switching loss. What does the 690mW limit really mean for a 3A load?

The 3V threshold also deserves a second look: it works from a 3.3V MCU, but with only 0.3V of gate headroom, R_DS(on) climbs far above the 10V spec. Drive it with 4.5V+ where the board allows.

When Should You Use (and NOT Use) the UT3N06G-AB3-R?

✅ Use UT3N06G-AB3-R when:

• Medium-current load switching. A 12V fan, a heater, an LED string — loads in the 0.5–2A range where a SOT-23 part runs hot and a DPAK is overkill.
• 60V voltage classes. 48V telecom rails, automotive 12V/24V with transients, and industrial 24V–48V buses all fit inside the 60V rating.
• PCB space is tight. SOT-89 is about the same footprint as SOT-23 but carries roughly 40% more power thanks to the drain tab soldered to the copper pour.
• Simple gate drive from 4.5V+ logic. Q_g of 10nC switches from a GPIO with no driver chip in between.
• Battery protection and power-path control. The 60V rating and 3A continuous current cover pack-level disconnect and reverse-polarity guard circuits.

❌ Don't use UT3N06G-AB3-R when:

• You actually need continuous 3A. 3A through 90mΩ is 0.81W of heat — above the 690mW package budget. For true 3A loads, step up to a DPAK (TO-252) like the NCE30H10K.
• Gate drive is only 3.3V and you can't afford the resistance. At V_GS=3.3V the part barely turns on; R_DS(on) sits far above spec. Use a logic-level part (V_GS(th) ≤1.5V class) instead.
• Switching above a few hundred kHz. C_iss of 780pF and 10nC gate charge are fine for load switching but heavy for a high-frequency converter stage.
• High-power hot-plug or inrush control. The 690mW budget doesn't cover the transient thermal load. Look at a TO-252 or TO-220 part with real thermal mass.

What Are the Alternatives to UT3N06G-AB3-R?

The SOT-89 class in one line: it's the package for loads that laugh at a SOT-23 but don't justify a DPAK. If the load is truly 3A continuous, the package answer isn't a bigger SOT-89 — it's a TO-252.

What Are the Typical Applications of UT3N06G-AB3-R?

12V fan and heater switching: a 1–2A 12V fan or PTC heater is the sweet spot for the SOT-89 class — the drain tab handles the thermal load with a modest copper pour, and the gate charge switches cleanly from a 5V GPIO.

Power-path and reverse-polarity protection: with 60V of drain-source rating, the UT3N06G sits comfortably on automotive 12V/24V rails and 48V telecom buses. A source-side arrangement plus a controller forms a classic reverse-battery guard.

Battery-pack disconnect circuits: the 3A continuous rating and low leakage (≤10µA) suit pack-level load disconnect. The 60V headroom absorbs charger transients without extra clamping.

LED string and solenoid drivers: for moderate LED currents or small solenoids in the 0.5–2A range, the UT3N06G replaces a relay with solid-state switching — no coil current, no contact wear.

Why Buy UT3N06G-AB3-R from ICMASS?

Every lot tested for R_DS(on) and threshold. We batch-test on-resistance and V_GS(th) on UT3N06Gs before shipping. The common counterfeit is a re-marked smaller die — it passes a continuity check but reads 2–3× the spec'd on-resistance, which turns your load switch into a heater.

Cross-reference support for the SOT-89 class. Not sure whether the board wants UT3N06G, NCE6003M, or a DPAK part? Send us your load current, thermal budget, and drive voltage — we'll tell you which package class the board actually needs.

BOM consolidation for switch and protection boards. The same product usually carries a comparator, a reference, and the UT3N06G. One shipment from Shenzhen covers the whole control and power section.

Same-day dispatch, 5–10 days worldwide. Orders before 15:00 CST ship same day via DHL or FedEx. For volume orders, we source directly from the UTC production line.

Frequently Asked Questions About UT3N06G-AB3-R

Q1: What is the big tab on the SOT-89 package?

A: The tab is the drain — and it's the heatsink path. In vertical MOSFETs the silicon substrate connects to the drain, so the exposed pad carries both the drain current and the heat. Solder the pad to a PCB copper pour; that pour is the heatsink.

Q2: Can I really run 3A through this part?

A: Only if the thermal budget allows it. 3A through 90mΩ means 0.81W of heat, above the 690mW package limit on standard pads. With a large copper pour it works; without one, the die runs hot and reliability drops. For true 3A continuous, a TO-252 is the honest choice.

Q3: Will a 3.3V MCU GPIO drive it?

A: It switches, but not at full performance. The 3V threshold leaves only 0.3V of headroom at 3.3V, so R_DS(on) runs far above the 10V spec. If the load is light it works; for real current, drive the gate with 4.5V or more, or pick a logic-level part with V_GS(th) under 1.5V.

Q4: Why does my MOSFET get hot even at low current?

A: Check the actual R_DS(on) — it rises with temperature. At 100°C the on-resistance is roughly 1.5× the 25°C spec, and at 125°C nearly 1.8×. A counterfeit or re-marked part can read 2–3× higher from the start, which turns a load switch into a heater.

Q5: Do I need a gate pull-down resistor?

A: Yes — it keeps the MOSFET off during MCU boot. A floating gate can be pulled on by noise and turn the load on before the firmware runs. A 10k resistor from gate to source holds the switch off, and costs nothing at switching speeds this slow.

Q6: What's the fastest this part can switch?

A: Practically, a few hundred kHz — it's a load switch, not a converter FET. With 10nC of gate charge and 780pF of input capacitance, switching edges at hundreds of kHz are fine. Above that, gate-drive losses and switching losses exceed the 690mW budget quickly.

Q7: Can I parallel two of them to split the current?

A: Yes — and it's often cheaper than a bigger package. Two parts at 1.5A each dissipate a quarter of the heat of one part at 3A. Match the parts from the same lot and give each its own gate resistor to avoid parasitic oscillation.

Q8: Does the tab need to connect to anything electrically?

A: It's the drain — it must connect to the drain circuit, not float. Some boards float the tab to "avoid shorts"; that starves the package of its heatsink path. Solder it to the drain net's copper pour. If you can't, you've crippled the thermal design.

Q9: SOT-23 vs SOT-89 — which should I use?

A: SOT-23 for signals, SOT-89 for power — the drain tab decides it. A SOT-23 part handles roughly 500mW; the SOT-89 carries about 40% more with a proper copper pour. If the load is under 1A and the board is tight, SOT-23 wins; for 1–2A continuous, SOT-89 is the right class.

Q10: How do I spot a fake UT3N06G?

A: Measure on-resistance at a known gate voltage — the fastest tell. Genuine parts read within spec of 90mΩ at V_GS=10V. Re-marked or clone parts typically read 2–3× higher because the die inside is smaller. Check the laser marking too — UTC markings are clean and consistent.