Infineon BTS142D High-Side Power Switch: Datasheet, Application Circuit, and Pin Configuration Guide
The Infineon BTS142D is a versatile and robust n-channel power FET integrated into a single chip, designed for high-side switching applications. Housed in a compact and industry-standard TO-252 (DPAK) package, this intelligent power switch (IPS) is a cornerstone solution for controlling a wide range of resistive or inductive loads in automotive and industrial systems. Its integrated features make it an ideal choice for applications demanding reliability, diagnostic feedback, and protection.
Pin Configuration Guide
The BTS142D features a simple three-pin configuration:
1. Pin 1 (IN): Input Pin. This is the control input. A logic-level voltage (typically above 3.5V) applied to this pin turns the power switch ON, allowing current to flow from the battery (Vbb) to the output. An internal pull-down resistor ensures a defined OFF state when the input is left floating.
2. Pin 2 (GND): Ground Pin. This pin provides the ground reference for both the power stage and the control logic. It must be connected directly to the system ground.
3. Pin 3 (OUT): Output Pin. This is the switched output that connects to the load. When the device is ON, the output is effectively connected to the battery supply (minus a small voltage drop). It is protected against short circuits to ground and battery.
Key Datasheet Parameters and Features
The strength of the BTS142D lies in its comprehensive suite of integrated protection and diagnostic features, as detailed in its datasheet.
Load Current Capability: It can handle a continuous DC current (Iout) of up to 17A, making it suitable for motors, lamps, and heaters.
Low On-State Resistance (RDS(on)): With a typical RDS(on) of only 16 mΩ, the device minimizes power loss and heat generation during operation, improving overall system efficiency.
Overload and Short-Circuit Protection (ISD): The device features non-latching current limitation that protects itself and the load during fault conditions. The status of this protection is reported via the diagnosis pin.
Overtemperature Protection (TSD): An integrated temperature sensor shuts down the power switch if the junction temperature exceeds a critical threshold (typically ~150°C). It automatically restarts once the chip has cooled down.
Overvoltage Protection (CLAMP): An internal active Zener clamp (typically 42V) protects the chip from voltage transients, such as those commonly found in automotive environments (load dump).
Diagnostic Feedback (DIAG): A crucial feature is the open-drain diagnosis output. This pin pulls to ground to signal fault conditions like overtemperature or overcurrent, providing critical feedback to the microcontroller (MCU).
Application Circuit
A typical application circuit for the BTS142D is straightforward, yet it highlights its intelligent features. The core connection involves:
The battery supply (Vbb, e.g., 12V) is connected directly to the chip's substrate and is available at the OUT pin through the internal FET.
The IN pin is driven directly by a microcontroller GPIO pin.
The load (e.g., a lamp, motor, or solenoid) is connected between the OUT pin and ground.
The DIAG pin is connected to a second microcontroller input pin via a pull-up resistor (e.g., 10kΩ) to the MCU's supply voltage (e.g., 5V or 3.3V). This allows the MCU to monitor the status of the power switch.
This simple setup allows a low-power MCU to safely control a high-power load while receiving real-time diagnostic information about the system's health.
ICGOODFIND Summary
The Infineon BTS142D is an exemplary high-side switch that combines robust power handling with critical protective functions. Its integrated diagnostics empower designers to build smarter, more reliable, and fault-resistant systems, particularly in the demanding automotive sector. The device simplifies design, reduces external component count, and provides a secure interface between sensitive microcontrollers and the harsh real-world power environment.
Keywords:
1. High-Side Switch
2. Intelligent Power Switch (IPS)
3. Diagnostic Feedback
4. Overcurrent Protection
5. Load Dump Protection
