MC33975ATEK

Specialized Overview

The MC33975ATEK is a multiple switch detection interface with suppressed wake-up and 32 mA wetting current, manufactured by NXP USA Inc. It detects up to 22 switch contacts via SPI. Operating from 5.5 V to 28 V on VPWR, it features 14 switch-to-ground inputs and 8 programmable inputs for battery or ground switches. The device supports selectable wetting currents of 32 mA or 4.0 mA and offers low sleep state currents of 100 µA (VPWR) and 20 µA (VDD). It operates within an ambient temperature range of -40 °C to 125 °C in a 32-pin SOICW-EP package.

Specialized Feature Summary

• Detects opening and closing of up to 22 switch contacts and transfers status to MCU via SPI.
• Features two operational modes: Normal mode for programming and monitoring, and Sleep mode for low quiescent current.
• Includes a 22-to-1 analog multiplexer for reading inputs as analog signals.
• Provides selectable wetting currents of 32 mA or 4.0 mA for switch-to-ground inputs.

Specialized Applications

• Automotive systems
• Industrial control systems
• Process control systems
• Security systems

Specialized Procurement Notes

Verify the specific ordering suffix EK indicates lead-free packaging compliant with JEDEC standards. Confirm the A variant designation corresponds to the extended switch input voltage range of -14 V to 40 VDC compared to the standard 33975 model. Ensure the supply chain source provides documentation confirming RoHS3 compliance and the correct thermal grade for automotive applications.

Specialized Selection Notes

Select this component when interfacing microprocessors to high-voltage switch matrices requiring contact wetting. The MC33975ATEK is suitable for environments demanding low sleep currents and robust switch detection. Verify that the system power supply remains within the 5.5 V to 28 V operating range. Ensure the MCU supports the required SPI protocol and voltage levels for reliable communication.

Specialized Part Context

This device belongs to the MC33975 family of specialized interface circuits designed for switch detection. It replaces discrete components in microprocessor-based systems by integrating switch ground offset protection and contact wetting capabilities. The part utilizes SMARTMOS technology for power management and includes internal protections against over-temperature and voltage anomalies.

Specialized Replacement Considerations

The MC33975TEK/R2 serves as a direct functional substitute with a switch input voltage range of -14 V to 38 VDC. Verify compatibility regarding the extended voltage tolerance if the application exceeds 38 VDC. Both parts share identical pinouts and operational modes.