MC33978EKR2

Specialized Overview

The MC33978EKR2 is a multiple switch detection interface IC designed to monitor up to 22 switch contacts. It transfers open or closed status to a microprocessor via a 3.3 V or 5.0 V SPI protocol. The device features a 24-to-1 analog multiplexer for reading input channels as analog signals, alongside integrated battery and temperature monitoring capabilities. It operates with a battery voltage range of 4.5 V to 36 V and includes selectable wetting currents ranging from 2 mA to 20 mA. The component supports Normal and Low-power modes, offering typical standby currents of 30 μA at VBATP and 10 μA at IDDQ.

Specialized Feature Summary

• Supports direct MCU interfacing using standard 3.3 V or 5.0 V SPI communication protocols.
• Provides independent programmable wetting currents to ensure reliable switch contact detection.
• Integrates a 24-to-1 analog multiplexer for buffered analog signal acquisition.
• Includes internal battery voltage sensing and temperature monitoring functions.

Specialized Applications

• Automotive body control modules
• Heating ventilation and air conditioning (HVAC) systems
• Programmable logic control (PLC)
• Central gateway and in-vehicle networking

Specialized Procurement Notes

Verify the EK suffix indicates a lead-free SOICW-EP package configuration. Confirm the R2 suffix corresponds to tape and reel packaging requirements. Ensure compatibility with automotive environmental standards before finalizing procurement specifications.

Specialized Selection Notes

Select this variant when a surface-mount SOICW-EP package is required for the design. Verify that the operating temperature range meets the application's thermal constraints. Ensure the host system supports the necessary SPI interface levels and wake-up configurations.

Specialized Part Context

This component belongs to the MC33978 family of specialized interface ICs. It serves as a bridge between mechanical switches and digital controllers in complex electronic systems. The device simplifies input handling by consolidating multiple switch detections into a single serial interface.

Specialized Replacement Considerations

MC33978EK

Specialized FAQ

What is the maximum number of switch contacts the device can detect?

The device is designed to detect the closing and opening of up to 22 switch contacts.

How does the device handle low-power operation?

It offers a Low-power mode (LPM) that provides low quiescent current, making it suitable for applications requiring minimal sleep-state power consumption.

Can the device measure external parameters besides switch states?

Yes, it includes an integrated battery monitor and temperature sensor accessible via the AMUX pin.