MC33972TEW

Specialized Overview

The MC33972TEW is a multiple switch detection interface with suppressed wake-up, designed to detect up to 22 switch contacts. It operates within a supply voltage range of 5.5 V to 26 V and features an SPI interface for MCU communication. The device includes 8 programmable inputs (SP0-SP7) configurable as switch-to-battery or switch-to-ground, and 14 fixed switch-to-ground inputs (SG0-SG13). It supports selectable wetting currents of 16 mA or 2.0 mA, typical standby current of 100 μA at VPWR, and operates from -40 °C to +125 °C in a 32-pin SOIC-Wide package.

Specialized Feature Summary

• Detects opening and closing of up to 22 switch contacts via SPI protocol
• Features 8 programmable inputs adaptable for battery or ground switching
• Includes 14 dedicated switch-to-ground input channels
• Provides analog multiplexing capability for all switch inputs

Specialized Applications

• Automotive body control modules
• Industrial control systems
• Telecommunications equipment

Specialized Procurement Notes

Verify the specific suffix 'EW' confirms lead-free packaging and standard SOIC-Wide form factor. Confirm that the component status aligns with project lifecycle requirements, as availability may vary by region. Ensure external reverse battery protection is included in the design, as the datasheet mandates it for the VPWR pin.

Specialized Selection Notes

Select this component when interfacing microprocessors with high-voltage automotive switches requiring low sleep current. Ensure the application utilizes a 3.3 V or 5.0 V logic level for the VDD pin. Verify that the system can accommodate the required external clamping for transients exceeding 40 V on the VPWR line.

Specialized Part Context

This part belongs to the MC33972 family of switch detection interfaces originally developed by Freescale Semiconductor. The TEW designation indicates a tape-and-reel variant in a 32-pin SOIC-Wide package. It serves as a bridge between mechanical switches and digital controllers, replacing discrete components in complex monitoring circuits.

Specialized Replacement Considerations

MC33972ATEW

Specialized FAQ

How are the SP0-SP7 inputs configured?

These eight inputs are programmable via the Settings Command register to function as either switch-to-battery or switch-to-ground contacts.

What is the function of the AMUX pin?

The AMUX pin provides the output of a 22-to-1 analog multiplexer, allowing any switch input to be read as an analog signal by the MCU.

How does the device handle wake-up from Sleep mode?

Wake-up can be triggered by a change-of-state on enabled switch inputs, expiration of the interrupt timer, or a falling edge on the WAKE or INT pins.