STMicroelectronics STL51N3LLH5

Overview

STL51N3LLH5 from STMicroelectronics is an N-channel Power MOSFET in PowerFLAT™ 5x6 package, rated for 30 V V_DS, 51 A continuous drain current at T_C = 25 °C, and 0.0105 Ω R_DS(on) at V_GS = 10 V. It employs STripFET™ V technology for ultra-low on-resistance and gate charge, targeting high-efficiency DC-DC converters and motor drive half-bridges.

For engineers reviewing the STL51N3LLH5 datasheet, STL51N3LLH5 pinout, STL51N3LLH5 application, or STL51N3LLH5 equivalent, key selection criteria include its 2 °C/W junction-to-case thermal resistance, 724 pF C_iss, 5 nC total gate charge, avalanche ruggedness, and FR-4 PCB thermal performance (R_thj-pcb = 31.3 °C/W).

Technical Context

This MOSFET uses ST's STripFET™ V trench-gate process to minimize conduction and switching losses simultaneously. Its low R_DS(on) × Q_g figure-of-merit enables high-frequency operation in synchronous buck converters with minimal power loss.

The device features a robust body diode with 21 ns reverse recovery time and 10 nC Q_rr at 150 °C, supporting fast-switching inductive load control. Its ±22 V gate rating and 30 V V_DS support 24 V industrial bus applications with margin.

Key Specifications

Pinout & Package

STL51N3LLH5 uses the PowerFLAT™ 5x6 surface-mount package (JEDEC MO-229WEED), with exposed drain pad for thermal and electrical connection. The package has 5 terminals: three drain pins (D), one source (S), and one gate (G), arranged in a single-row configuration optimized for PCB copper area utilization and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRL3803PbF and SiR872DP-T1-GE3, STL51N3LLH5 delivers optimal balance of low Q_g, proven avalanche capability, and cost-effective PowerFLAT™ packaging - making it preferred for space-constrained, medium-frequency industrial switching where reliability under transient stress is critical.

Availability

STL51N3LLH5 is available at Aetrix Electronics and suitable for DC-DC converters, motor drives, LED drivers, and hot-swap controllers requiring stable component supply and consistent parametric performance across production lots.

Supply support for STL51N3LLH5 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 microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

This device belongs to ST's STripFET™ V Power MOSFET product line, engineered specifically for high-efficiency, high-power-density switching applications in industrial power supplies and motor control systems.

FAQ

What is the maximum safe operating temperature for STL51N3LLH5?

The STL51N3LLH5 has a maximum operating junction temperature of 150 °C. When mounted on a standard FR-4 PCB (1 in², 2 oz Cu), its junction-to-PCB thermal resistance is 31.3 °C/W. At 51 A continuous current and 0.0105 Ω R_DS(on), power dissipation reaches ~28 W - requiring careful thermal layout or forced cooling to stay within the 150 °C limit.

Can STL51N3LLH5 be used in parallel configurations?

Yes, STL51N3LLH5 supports paralleling due to its positive temperature coefficient of R_DS(on), which promotes current sharing. However, matched gate resistors (≤1 Ω) and symmetrical PCB routing are required. Derate total current by 15% per additional device to account for layout-induced thermal imbalance and parameter spread.

Does STL51N3LLH5 require a gate resistor for ESD protection?

No - the device does not integrate internal gate protection diodes. A discrete 10–100 Ω series gate resistor is recommended to dampen ringing and limit peak gate current during fast switching, especially when driven by logic-level sources. For ESD immunity, layout must include short gate traces and local 100 nF decoupling near the gate pad.

Is the body diode suitable for continuous freewheeling in synchronous rectification?

Yes - the intrinsic body diode is characterized for 12.6 A continuous forward current and 50.4 A pulsed current. With 1.1 V forward voltage at 12.6 A and 21 ns reverse recovery time, it supports synchronous rectification in buck converters up to 500 kHz, though external Schottky diodes may be preferred for >1 MHz operation to minimize Q_rr-related losses.