STMicroelectronics STL55NH3LL

Overview

STL55NH3LL from STMicroelectronics is an N-channel Power MOSFET optimized for high-efficiency switching in space-constrained DC-DC converters and load switches, featuring 30 V V_DS, 7.9 mΩ R_DS(on) at V_GS = 10 V, 15 A continuous drain current (T_C = 25 °C), ultra-low 9 nC total gate charge, and PowerFLAT™ (6×5) package with 1 mm max profile.

For engineers reviewing the STL55NH3LL datasheet, STL55NH3LL pinout, STL55NH3LL application, or STL55NH3LL equivalent, key selection criteria include low R_DS(on) at 4.5 V drive, thermal resistance of 31.3 °C/W on FR-4, avalanche energy rating of 150 mJ, and compatibility with compact board layouts requiring minimal footprint and height.

Technical Context

This STripFET™-based MOSFET employs a trench-gate structure to minimize conduction and switching losses simultaneously. Its low threshold voltage (1–2.5 V) enables direct logic-level drive from 3.3 V or 5 V controllers, while its 965 pF input capacitance and 38 pF reverse transfer capacitance support fast, controlled turn-on/turn-off with minimal ringing.

The device is characterized for unclamped inductive switching with single-pulse avalanche capability up to 7.5 A and 150 mJ, and features a source-drain diode with 1.3 V forward voltage at 15 A and 24 ns reverse recovery time-critical for synchronous rectification and flyback topologies.

Key Specifications

Pinout & Package

STL55NH3LL uses the PowerFLAT™ (6×5) package: surface-mount, 5-pin, exposed drain pad (pins 1–4 = source, pin 5 = gate), 6 mm × 5 mm footprint, 0.83 mm typical height, JEDEC-compliant lead-free construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel power MOSFET applications.

Compared with STL55NH3LL, BSC014N04LS trades board space and switching speed for lower conduction loss, while SiR872DP matches mechanical fit but sacrifices avalanche robustness-making STL55NH3LL optimal where compact size, fast switching, and transient resilience are jointly required.

Availability

STL55NH3LL is available at Aetrix Electronics and suitable for DC-DC buck converters, USB-C load switches, and automotive body control modules requiring stable component supply across extended production lifecycles.

Supply support for STL55NH3LL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for industrial, automotive, and consumer markets.

The STL55NH3LL belongs to ST's STripFET™ Power MOSFET product line, engineered specifically for high-density power conversion where low R_DS(on), low Q_g, and compact packaging are critical.

FAQ

What is the maximum safe operating temperature for STL55NH3LL?

The STL55NH3LL has a rated junction temperature range of –55 °C to +150 °C. Its thermal resistance junction-to-ambient is 31.3 °C/W on a standard FR-4 board (1 in², 2 oz Cu). To maintain reliability, sustained operation above 125 °C junction temperature should be avoided; derating curves in Figure 3 confirm safe operation up to 150 °C only under pulsed or thermally managed conditions.

Can STL55NH3LL be driven directly by a 3.3 V microcontroller?

Yes. With a gate threshold voltage of 1–2.5 V and guaranteed R_DS(on) of 9 mΩ at V_GS = 4.5 V, the STL55NH3LL fully turns on using a 3.3 V GPIO. At 3.3 V, R_DS(on) rises to ~11.5 mΩ (per Table 5), still supporting ≤10 A continuous current with acceptable loss-ideal for logic-level switching in battery-powered systems.

Does STL55NH3LL have built-in ESD protection?

No. The STL55NH3LL does not integrate dedicated ESD protection circuitry. Its gate oxide is rated for ±16 V continuous and ±18 V short-duration (≤15 ms) gate-source voltage. External TVS diodes or RC snubbers are recommended on gate traces in environments with high static or fast transient coupling, especially in handheld or automotive assembly lines.

Is the PowerFLAT™ (6x5) package compatible with standard reflow profiles?

Yes. As an ECOPACK®-compliant, lead-free device, STL55NH3LL supports standard IPC/JEDEC J-STD-020D reflow profiles. Peak temperature must not exceed 260 °C for ≤30 seconds, and the exposed drain pad requires full solder coverage to ensure thermal and mechanical reliability-verified per ST's package mechanical data (Figure 21, page 11).