MC33978
description
The 33978 is designed to detect the closing and opening of up to 22 switch contacts. The switch status, either open or closed, is transferred to the microprocessor unit (MCU) through a serial peripheral interface (SPI). Individually selectable input currents are available in Normal and Low-power (LPM) modes, as needed for the application.
It also features a 24-to-1 analog multiplexer for reading inputs as analog. The analog input signal is buffered and provided on the AMUX output pin for the MCU to read. A battery and temperature monitor are included in the IC and available via the AMUX pin.
The 33978 device has several modes of operation: Normal mode, Low-power mode (LPM), and Polling mode. Normal mode allows programming of the device and supplies switch contacts with pull-up or pull-down current as it monitors the change of state of switches. The LPM provides low quiescent current, which makes the 33978 ideal for automotive and industrial products requiring low...
