Content last revised on February 8, 2026
STK621-210B: Integrated 3-Phase Motor Driver for Compact and Reliable Inverter Systems
The STK621-210B is a highly integrated hybrid IC (HIC) engineered to simplify the design and enhance the reliability of three-phase motor drive systems. By combining a pre-driver IC and IGBT output stage in a single compact SIP package, it offers a robust solution for controlling brushless DC and permanent magnet synchronous motors. Key specifications include a 450V maximum supply voltage (V_BB) and a 10A output current (I_O). The primary engineering benefits are a significant reduction in PCB footprint and enhanced system protection. This device directly addresses the need for compact motor control circuits in applications like inverter air conditioners and industrial automation by providing an all-in-one drive solution. For systems demanding higher current capabilities, the related BSM35GP120 offers a different performance profile within a module format.
Application Scenarios & Value
System-Level Benefits in Appliance and Light Industrial Motor Control
The STK621-210B is optimized for applications where space constraints and reliability are critical design drivers. Its best fit is in variable speed drives for motors rated up to approximately 750W, making it an ideal choice for the compressors in inverter air conditioners, drum motors in high-efficiency washing machines, and fans or pumps in light industrial equipment. The high level of integration is the defining value proposition for engineers. By incorporating the high-voltage gate driver (HVIC) and bootstrap diodes directly into the module, it eliminates the need for numerous external components. This design simplification translates directly into a smaller PCB, reduced assembly complexity, and a lower potential for noise-induced failures that can plague discrete designs. The integrated protection features, such as overcurrent and thermal shutdown, provide a critical safety net, enhancing the robustness of the end-product without requiring additional external monitoring circuitry.
Key Parameter Overview
Decoding the Specs for Integrated Motor Drive Design
The technical specifications of the STK621-210B are tailored for efficient and protected motor operation. The parameters below highlight its capability as a self-contained power stage solution. Understanding these values is key to implementing it effectively in a target design.
| Parameter | Value | Significance |
|---|---|---|
| Maximum Supply Voltage (V_BB(max)) | 450 V | Defines suitability for systems operating on rectified 200/240 VAC mains voltage. |
| Output Current (I_O) | 10 A | Determines the maximum continuous motor current handling capability. |
| Peak Output Current (I_O peak) | 20 A (t ≤ 1s) | Indicates the ability to handle short-duration motor startup or load transients. |
| Control Supply Voltage (V_CC) | 20 V | Specifies the required voltage for the internal logic and low-side gate drive. |
| Bootstrap Supply Voltage (V_BS) | 20 V | Specifies the required voltage for the high-side gate drive supply. |
| Integrated Features | Bootstrap Diodes, Overcurrent Protection (OCP), Thermal Shutdown (TSD), UVLO | Provides a comprehensive set of functions to simplify design and protect the system. |
Frequently Asked Questions (FAQ)
What is the primary benefit of the STK621-210B's hybrid IC design?
Its primary benefit is system simplification. By integrating the gate drive and protection circuits with the IGBT power stage in a single package, it reduces external component count, minimizes PCB area, and shortens the design and validation cycle for the motor drive.
How does the integrated Overcurrent Protection (OCP) function?
The module includes an internal shunt resistor for current sensing. If the output current exceeds a predefined threshold, the internal protection logic triggers a fault signal and safely shuts down the IGBTs, preventing damage to both the module and the motor during overload or short-circuit events.
What design considerations are important when using the STK621-210B?
Proper thermal management is critical. Due to its compact SIP form factor, it must be mounted securely to an appropriately sized heatsink to dissipate heat effectively and stay within its safe operating temperature. Additionally, the layout of the control supply (V_CC) and bootstrap capacitors should follow datasheet recommendations to ensure stable gate drive operation.
Can the STK621-210B be directly driven by a 3.3V or 5V microcontroller?
Yes, the logic-level inputs (IN(UH), IN(VH), IN(WH), etc.) are designed to be compatible with standard 3.3V or 5V CMOS logic signals from a microcontroller (MCU), allowing for direct interface without the need for level-shifting circuitry.
From a strategic standpoint, the STK621-210B represents a design philosophy focused on integration to achieve higher reliability and a more compact form factor in moderate power applications. It provides engineers with a pre-validated power stage, allowing them to focus resources on system-level control software and application features rather than the complexities of discrete gate drive and protection circuit design. This approach is particularly advantageous in high-volume, cost-sensitive markets like consumer appliances and automated systems where both performance and manufacturing efficiency are paramount.