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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

STMicroelectronics STK850

Name: STK850
Brand: STMicroelectronics
SKU: STK850
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STK850

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: PolarPak®

Datasheet:: STK850.pdf

Description:: MOSFET N-CH 30V 30A POLARPAK

Quantity:: RFQ Add To RFQ list

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Inventory:5,351

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Product details

Overview

STK850 from STMicroelectronics is an N-channel 30V PolarPAK® Power MOSFET optimized for high-current switching applications, featuring R_DS(on) = 0.0024 Ω at V_GS = 10 V, 30 A continuous drain current at T_C = 25°C, ultra-low junction-to-case thermal resistance (0.8 °C/W top-side), and 24.5 nC total gate charge - deployed in DC-DC converters and motor drive half-bridges.

For engineers reviewing the STK850 datasheet, STK850 pinout, STK850 application, or STK850 equivalent, key selection criteria include verified R_DS(on) at 4.5 V (0.0029 Ω), double-sided cooling capability, avalanche energy rating (1.4 J), and PolarPAK® package mechanical dimensions per Figure 22 and Table 8.

Technical Context

This device implements ST's "single feature size" strip-based process to maximize die packing density and minimize on-resistance. Its dual-side thermal interface enables simultaneous top-drain and bottom-source heat extraction, supported by measured R_thj-c values of 0.8 °C/W (top) and 2.2 °C/W (source).

The MOSFET delivers fast switching with t_d(on) = 20 ns and t_f = 13 ns under 15 V/15 A/4.7 Ω gate drive, while maintaining low dynamic losses via C_iss = 3150 pF and Q_gd = 8.2 nC - critical for high-frequency synchronous rectification and PWM motor control.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	30 V - maximum blocking voltage for 24 V system-level switching
R_DS(on)	0.0024 Ω @ V_GS = 10 V - enables <1 W conduction loss at 20 A
I_D (cont)	30 A @ T_C = 25°C - supports high-current load switching without forced air
Q_g	24.5 nC - determines gate driver power requirement and switching speed trade-off
R_thj-c (top)	0.8 °C/W - allows direct heatsink mounting to drain pad for efficient double-side cooling
E_AS	1.4 J - rated single-pulse avalanche energy for inductive load turn-off robustness
C_iss	3150 pF @ V_DS = 25 V - impacts Miller effect and gate drive stability in hard-switched topologies

Pinout & Package

PolarPAK® is a surface-mount, dual-side thermal package with exposed top drain and bottom source terminals. It uses a 6-pin configuration with integrated thermal pads on both sides for PCB-level heat spreading.

Pin/Terminal	Circuit Role	Design Meaning
Drain (Top Pad)	Main current path output / high-side switch node	Exposed copper area for direct heatsink attachment; primary thermal path to ambient
Source (Bottom Pad)	Return path for load current / reference node	Thermally conductive bottom termination enabling PCB copper pour cooling
Gate (Pin 1)	Control input for channel modulation	Low-capacitance input requiring <25 nC drive for full enhancement
Source (Pin 2)	Signal ground reference for gate drive	Separate low-inductance source connection to minimize common-source inductance
Drain (Pin 3)	Secondary drain connection	Redundant current path to reduce package resistance and improve current sharing
Source (Pin 4)	Additional source tie point	Enables multi-point grounding for noise-sensitive gate drive loops

Key Features

Feature	Design Value
Ultra-low R_thj-c (top)	0.8 °C/W enables >50% higher power density vs. standard SO-8 MOSFETs in same footprint
Double-side cooling architecture	Simultaneous top-drain and bottom-source thermal paths reduce total thermal resistance by 35% over single-side packages
100% R_g tested	Guarantees gate resistance consistency for predictable switching timing across production lots
Matte tin finish	RoHS-compliant 100% matte tin plating ensures reliable solder wetting and long-term intermetallic stability
Low C_oss & C_rss	940 pF C_oss and 90 pF C_rss minimize Miller-induced shoot-through risk in synchronous buck stages

Applications

DC-DC Converter Primary Switch

Brushless DC Motor Half-Bridge

Use Scenario: High-efficiency 12–24 V input buck converter delivering up to 30 A to FPGA core rails.

IC Role / Device Role / Timing Role: Main high-side switching element in synchronous rectification topology operating at 300–500 kHz.

Use Value: 0.0024 Ω R_DS(on) limits conduction loss to <1.5 W at full load; low Q_g enables use of compact gate drivers like STMicro's STL220.

Use Scenario: 24 V BLDC motor controller driving 500 W fans or pumps in HVAC systems.

IC Role / Device Role / Timing Role: Low-side switch in three-phase inverter leg, commutated at ≤20 kHz with PWM dead-time control.

Use Value: 1.4 J E_AS withstands inductive flyback during rapid PWM transitions; 120 A pulsed ID supports torque surge peaks.

Automotive Body Control Module

Industrial Solenoid Driver

Use Scenario: Load-driving stage in 12 V automotive BCM for headlight relays and window lift motors.

IC Role / Device Role / Timing Role: Protected high-current switch interfacing with microcontroller GPIO via level-shifting gate driver.

Use Value: -55 to 150 °C T_J range meets AEC-Q101 ambient requirements; 100% R_g test ensures consistent turn-on delay across temperature.

Use Scenario: 24 V solenoid actuator driver in factory automation valves and pneumatic controls.

IC Role / Device Role / Timing Role: Fast-turning, avalanche-rated switch handling 100 ms inductive transients during de-energization.

Use Value: Ultra-low R_thj-c prevents thermal runaway during repetitive 1 Hz duty cycling; V_GS(th) = 1–2.5 V ensures clean logic-level compatibility.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL220N3LLH6	30 V, 220 A, R_DS(on) = 0.00095 Ω @ 10 V, PowerFLAT™ 5x6 package, lower R_thj-c (0.5 °C/W)	Higher current capacity and better thermal performance but larger footprint and higher gate charge (42 nC)	Preferred for new designs needing >100 A peak current and tighter thermal budgets
IRF7470PBF	30 V, 30 A, R_DS(on) = 0.0028 Ω @ 10 V, SO-8 package, R_thj-c = 3.5 °C/W, no double-side cooling	Limited to single-side cooling; higher thermal resistance increases board-level temperature rise by ~25 °C at 20 A	Suitable only when PolarPAK® assembly infrastructure is unavailable and lower current derating is acceptable

Compared with STL220N3LLH6 and IRF7470PBF, STK850 offers balanced performance: superior thermal resistance versus SO-8 alternatives and lower gate charge than high-current PowerFLAT™ devices - making it optimal for space-constrained 30–50 A industrial switching where thermal management and driver simplicity are co-priorities.

Availability

STK850 is available at Aetrix Electronics and suitable for DC-DC converters, BLDC motor drives, automotive body control modules, and industrial solenoid drivers requiring stable component supply amid obsolescence-sensitive legacy designs.

Supply support for STK850 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, discrete components, and MEMS sensors for industrial, automotive, and consumer markets.

The STK850 belongs to ST's PolarPAK® Power MOSFET product line, engineered specifically for high-power-density switching applications demanding dual-side thermal extraction and low-loss operation in compact form factors.

FAQ

Is STK850 RoHS-compliant and lead-free?

Yes. STK850 features 100% matte tin finish and complies with Directive 2002/95/EC. It is part of ST's ECOPACK® initiative, with lead-free second-level interconnect and JEDEC JESD97 marking on packaging. No lead or hazardous substances exceed EU RoHS thresholds.

What is the maximum safe operating temperature for STK850?

The absolute maximum junction temperature (T_J) is 150°C, with storage temperature ranging from –55°C to +150°C. Derating begins at T_C = 25°C using 0.0416 W/°C, meaning power dissipation must be reduced linearly above that case temperature to maintain safe operation.

Can STK850 be driven directly from a 3.3 V microcontroller GPIO?

No. With V_GS(th) = 1–2.5 V and R_DS(on) = 0.0029 Ω only at V_GS = 4.5 V, a 3.3 V drive yields significantly higher on-resistance (>0.004 Ω) and unreliable switching. A dedicated gate driver (e.g., STMicro's TS1700x series) is required for full enhancement and fast transition control.

Does STK850 support avalanche operation in unclamped inductive switching?

Yes. STK850 is rated for 1.4 J single-pulse avalanche energy (E_AS) at T_J = 25°C, I_D = 15 A, and V_DD = 25 V. This enables robust operation in relay drivers and solenoid circuits where inductive kickback exceeds V_DS rating, provided pulse duration and repetition rate remain within SOA limits shown in Figure 2.

STK850 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: STripFET™

Package/Case:: PolarPak®

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 30 V

Current - Continuous Drain (Id) @ 25°C:: 30A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 2.9mOhm @ 15A, 10V

Vgs(th) (Max) @ Id:: 2.5V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 32.5 nC @ 4.5 V

Vgs (Max):: ±16V

Input Capacitance (Ciss) (Max) @ Vds:: 3150 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 5.2W (Tc)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PolarPak®

STK850 FAQ

1.How can I place an order for STK850 through Aetrix?

Please submit a Request for Quotation (RFQ) for STK850 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for STK850 reliable?

The price and inventory of STK850 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STK850 is usually 5 days.

3.What payment methods are accepted for STK850?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STK850 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STK850?

STK850 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STK850 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for STK850?

For technical support, including STK850 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STK850 requirements.

6.How does Aetrix verify that STK850 is sourced from the original manufacturer or authorized distributors?

All STK850 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STK850 meets industry standards.

7.What is the process for return or replacement of STK850?

All STK850 units undergo pre-shipment inspection (PSI). If there is an issue with STK850, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The STK850 part is unused and in its original packaging.

Return procedure for STK850:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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