Infineon BTS50085-1TMAATMA1 High-Current PROFET™ Smart Switch: Datasheet, Application Circuit, and Design Guide

Modern automotive and industrial systems demand robust, intelligent, and highly reliable solutions for switching high-current loads. The Infineon BTS50085-1TMAATMA1 stands out as a premier device in this domain, representing a pinnacle of power management technology. As part of Infineon's PROFET™ (Protected MOSFET) family of smart high-side switches, this component integrates a vertical power MOSFET with a suite of advanced protection and diagnostic features into a single, compact package. It is engineered to handle challenging high-current loads up to 85A, making it an ideal choice for applications such as heating elements, motor control, and power distribution units.

Key Features from the Datasheet

The datasheet for the BTS50085-1TMAATMA1 reveals a component built for performance and resilience. Key electrical characteristics include a very low typical on-state resistance (RDS(on)) of just 2.5 mΩ, which is instrumental in minimizing conduction losses and improving overall system efficiency. This results in less heat generation, reducing the burden on thermal management systems.

Beyond its raw switching capability, the device is defined by its integrated smart features:

Comprehensive Protection: It includes overload protection, short-circuit protection, and overtemperature protection with precise, adjustable current limitation. The device also features protection against reverse polarity and overvoltage conditions (such as load-dump), safeguarding both the switch and the connected load.

Advanced Diagnostics: A crucial feature is the diagnostic feedback pin. It provides real-time information on the operational status, including open-load detection (both pre- and post-operation), overcurrent warnings, and overtemperature shutdown alerts. This enables predictive maintenance and swift fault identification.

Controlled Switching: The device offers an adjustable slew rate via an external capacitor on the IN pin, allowing engineers to manage electromagnetic interference (EMI) by controlling the inrush current during turn-on.

Typical Application Circuit

Implementing the BTS50085-1TMAATMA1 is remarkably straightforward, a significant advantage highlighted in its design guide. A basic application circuit requires only a few external components:

1. Microcontroller (MCU): The switch is controlled by a logic-level signal (typically 3.3V or 5V) applied to the IN (Input) pin.

2. Power Supply: The battery or system power rail (4V to 28V) is connected to the VS (Supply Voltage) pin.

3. Load: The high-current load (e.g., a lamp, motor, or heater) is connected between the OUT (Output) pin and ground.

4. Diagnostics: The DIAG (Diagnostic) pin is connected to a microcontroller ADC input to read the analog diagnostic feedback current.

5. External Components: A small capacitor on the IN pin may be used to adjust the slew rate, and a pull-down resistor on the IN pin ensures defined behavior during MCU startup. A sense resistor on the IS (Sense) pin can be added for precise current measurement, though the device's internal current limitation often makes this optional.

This simplicity drastically reduces PCB footprint and design complexity compared to discrete solutions.

Essential Design Guide Considerations

To ensure reliable operation, several design factors must be addressed:

Thermal Management: Despite its low RDS(on), switching high currents generates heat. The TO-263-7 (D2PAK) package is designed for excellent thermal performance and must be soldered to a sufficiently large PCB copper area acting as a heat sink. Thermal vias can be used to transfer heat to inner or bottom layers.

Grounding: A stable and low-impedance ground connection is critical for accurate current sensing and diagnostic functionality.

EMI Mitigation: The adjustable slew rate feature should be utilized to balance switching speed and EMI generation, which is paramount in automotive environments.

Diagnostics Interpretation: The designer must implement firmware to correctly interpret the analog current signal from the DIAG pin to distinguish between normal operation and various fault conditions.

ICGOOODFIND

The Infineon BTS50085-1TMAATMA1 is an exceptionally capable and intelligent high-side switch. Its integration of a high-power switch, robust protection mechanisms, and detailed diagnostic feedback into a single package simplifies design, enhances system reliability, and reduces total cost of ownership. It is a superior solution for designers seeking to manage high-current loads in demanding automotive and industrial applications efficiently.

Keywords:

1. PROFET™ Smart Switch

2. High-Current Load (85A)

3. Integrated Protection Features

4. Diagnostic Feedback

5. Low RDS(on)