Infineon BTS426L1: High-Performance Smart High-Side Power Switch

The Infineon BTS426L1 represents a significant advancement in the realm of high-side power switches, integrating robust power handling with intelligent control and diagnostic features. Designed for demanding automotive and industrial applications, this device simplifies circuit design, enhances system reliability, and provides critical protection in a compact package.

As a smart high-side switch, the BTS426L1 is engineered to control resistive, capacitive, and inductive loads with a continuous current capability of up to 42A. Its core is built upon Infineon’s proven PROFET™ (Protected MOSFET) technology, which combines a vertical power MOSFET with a sophisticated CMOS control circuit on a single chip. This integration allows for direct interfacing with microcontrollers, as the device can be controlled by a low-level logic signal (as low as 3.3V), eliminating the need for additional driver circuits.

A key strength of the BTS426L1 lies in its comprehensive suite of integrated protection features. These include:

Overload and Short-Circuit Protection: The device actively limits the output current to protect itself and the connected load in fault conditions.

Overtemperature Protection: An internal temperature sensor shuts down the power stage if the junction temperature exceeds a critical threshold, restarting automatically upon cooling.

Overvoltage Protection (including load-dump): It is resilient against voltage transients common in automotive environments.

Reverse Battery Protection: The switch is inherently protected against a reversed supply voltage of up to -18V, safeguarding the system without requiring an external series diode.

Furthermore, the BTS426L1 provides precise diagnostic feedback to the system microcontroller. It offers a current sense pin that delivers a proportional current mirroring the load current, enabling real-time monitoring. It also features an open-drain status flag that signals error conditions such as overtemperature, short-circuit, and open-load (in off-state), which is crucial for predictive maintenance and system debugging.

Housed in a TO-263-7 (D2PAK) package with an exposed cooling tab, the device offers excellent thermal performance, efficiently dissipating heat into the PCB to maintain high operational reliability.

ICGOODFIND: The Infineon BTS426L1 stands out as a superior solution for high-current switching, offering an optimal blend of high power density, intelligent control, and robust integrated protection. It significantly reduces system complexity and bill-of-materials costs while ensuring maximum reliability in harsh operating environments.

Keywords: High-Side Switch, Integrated Protection, Diagnostic Feedback, PROFET™, Automotive Grade.