Infineon BTS117BKSA1 Smart High-Side Power Switch: Datasheet, Pinout, and Application Circuits

The Infineon BTS117BKSA1 is a versatile and robust smart high-side power switch designed for a wide range of automotive and industrial applications. This device integrates a N-channel vertical power MOSFET with comprehensive protection and diagnostic features, all housed in a compact TO-263-7 (D2PAK) surface-mount package. Its primary function is to act as an electronically controlled switch, capable of efficiently driving resistive or inductive loads such as solenoids, valves, motors, and lamps with a continuous current of up to 8.5A.

Datasheet Overview: Key Parameters and Features

The datasheet for the BTS117BKSA1 reveals a component engineered for reliability and system integration. Key electrical characteristics include a low on-state resistance (RDS(on)) of typically 85 mΩ, which minimizes power loss and heat generation. The device operates from a nominal supply voltage range of 5.5V to 34V, making it suitable for standard 12V and 24V automotive systems. A logic-level input (as low as 3.3V) controls the switch, allowing for direct interfacing with microcontrollers without the need for additional level-shifting circuitry.

Its integrated smart features are a significant advantage:

Overload and Short-Circuit Protection: The switch current is limited to protect itself and the load.

Overtemperature Protection: The device shuts down if the junction temperature exceeds a safe threshold.

Overvoltage Protection (including load-dump): Clamps the output to protect the internal circuitry.

Ground Loss and Supply Loss Protection: Ensures correct operation even in faulty wiring conditions.

Diagnostic Feedback: The status output pin provides a feedback signal to the microcontroller, indicating faults like overtemperature or open-load conditions when the switch is off.

Pinout Configuration

Understanding the pinout is crucial for PCB design. The BTS117BKSA1 in the D2PAK-7 package has the following pins:

1. IN (Input): Logic control input. A high-level signal (> 3.5V) turns the power MOSFET on.

2. SR (Status Report / Diagnostic Output): Open-drain output that pulls low to signal a fault condition.

3. GND (Ground): Reference ground for the logic and protection circuits.

4. n.c. (No Connection): This pin is not internally connected.

5. OUT (Output): The switched output connected to the load.

6. VS (Supply Voltage): Connects to the positive battery rail or main power supply.

7. n.c. (No Connection): This pin is not internally connected.

Application Circuits

The BTS117BKSA1 simplifies circuit design by replacing discrete solutions involving MOSFETs, drivers, and protection components.

1. Basic Solenoid/Valve Driver:

The most straightforward application is driving an inductive DC load. The IN pin is connected to a microcontroller GPIO pin. The SR pin is connected to another microcontroller input pin via a pull-up resistor to the MCU's supply voltage (e.g., 5V or 3.3V). A flyback diode is integrated within the switch, making an external one optional for most applications. A bypass capacitor (e.g., 100nF) placed close to the VS and GND pins is essential for stability.

2. Automotive Lamp Driver:

When driving lamps (incandescent bulbs), the inrush current can be very high. The BTS117BKSA1's built-in current limiting actively manages this surge, providing a soft-start effect that enhances bulb life. The diagnostic feature can detect a burnt-out bulb (open-load) when the switch is commanded on.

3. Modular System Design:

Multiple BTS117BKSA1 devices can be easily paralleled on a PCB, with each MCU GPIO controlling a separate channel. This creates a compact and highly reliable multi-channel power driver module for body control units (BCUs) or industrial PLCs, reducing board space and design complexity compared to discrete solutions.

ICGOODFIND Summary

The Infineon BTS117BKSA1 stands out as an all-in-one intelligent switching solution that dramatically reduces design complexity and boosts system reliability. By integrating the power stage, driver, and extensive protection circuitry into a single package, it provides a robust interface between sensitive microcontrollers and harsh real-world loads. Its diagnostic capabilities enable smarter, more fault-resistant systems, making it an excellent choice for demanding automotive and industrial control applications.

Keywords: Smart High-Side Switch, BTS117BKSA1, Automotive Power Management, Diagnostic Feedback, Integrated Protection