STMicroelectronics STK800

Overview

STK800 from STMicroelectronics is an N-channel 30V PolarPAK® Power MOSFET optimized for high-current switching applications, featuring R_DS(on) = 0.006 Ω at V_GS = 10 V, 20 A continuous drain current at T_C = 25°C, and ultra-low junction-to-case thermal resistance (1.0 °C/W top-side), enabling double-sided cooling in compact power stages.

For engineers reviewing the STK800 datasheet, STK800 pinout, STK800 application, or STK800 equivalent, this device is selected for high-efficiency DC-DC converters, motor drive half-bridges, and synchronous rectification where low conduction loss, fast switching (t_d(on) = 15 ns), and robust avalanche capability (E_AS = 1 J) are critical.

Technical Context

The STK800 employs ST's "single feature size" strip-based process to achieve high cell density and minimal on-resistance. Its PolarPAK® package integrates a fully encapsulated die with matte tin finish and dual thermal paths-top-side drain and source-side case-supporting simultaneous top and bottom heat extraction.

Electrically, it delivers low gate charge (Q_g = 13.4 nC), low output capacitance (C_oss = 450 pF), and stable threshold voltage (V_GS(th) = 1–2.5 V), enabling efficient 4.5 V logic-level drive and predictable turn-on/turn-off behavior in hard-switched topologies.

Key Specifications

Pinout & Package

PolarPAK® is a surface-mount, dual-side thermal package with exposed top-side drain and bottom-side source terminals. It uses a 6-pin configuration (3 drain pads + 3 source pins) optimized for PCB copper area thermal spreading.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si7157DP and BSC014N04LS, STK800 uniquely balances 30 V rating, 20 A current capability, 1.0 °C/W top-side thermal resistance, and 1 J avalanche energy - making it optimal for thermally dense 24 V motor and converter designs where both conduction loss and fault robustness matter.

Availability

STK800 is available at Aetrix Electronics and suitable for DC-DC converters, motor drive half-bridges, synchronous rectification, and power OR-ing circuits requiring stable component supply despite its obsolete status through legacy inventory and controlled distribution channels.

Supply support for STK800 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, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The STK800 belongs to ST's PolarPAK® Power MOSFET product line, engineered specifically for high-power-density switching applications where dual-side thermal management and low R_DS(on) are essential in space-constrained PCBs.

FAQ

Is STK800 still in active production?

No - STK800 is marked as obsolete per ST's official documentation (Rev 9, October 2007). However, Aetrix Electronics maintains verified legacy stock with full traceability, including original packaging (tape & reel) and date-code authenticity, supporting ongoing production of legacy systems.

Can STK800 be driven directly by 3.3 V microcontrollers?

No - STK800 has a gate threshold voltage range of 1–2.5 V but requires ≥4.5 V for reliable R_DS(on) specification (0.0075 Ω max). Driving with 3.3 V yields significantly higher on-resistance (>0.02 Ω), increasing conduction loss and thermal stress; a gate driver or level shifter is mandatory.

What is the maximum PCB copper area needed for thermal performance?

Per ST's recommended PAD layout (Figure 23), the top drain pad requires ≥100 mm² of 2 oz copper, while each source pin connects to ≥25 mm² of dedicated ground plane. Total thermal pad area should exceed 200 mm² to achieve the specified 1.0 °C/W R_thj-c (top) under steady-state conditions.

Does STK800 support paralleling for higher current?

Yes - its positive temperature coefficient of R_DS(on) (see Figure 11) ensures inherent current sharing. ST recommends matched gate drive routing, symmetrical PCB copper, and individual 4.7 Ω gate resistors to minimize oscillation; paralleled operation up to 40 A has been validated in reference designs using two STK800s.