MC33975ATEK is a multiple switch detection interface with suppressed wakeup 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). The device also features a 22-to-1 analog multiplexer for reading inputs as analog. It has two modes of operation, Normal and Sleep. Normal mode allows programming of the device and supplies switch contacts with pull-up or pull-down current as it monitors the switch change of state. The Sleep mode provides low quiescent current, which makes the 33975 ideal for automotive and industrial products requiring low sleep state currents. The application includes automotive systems, industrial control systems, process control systems, security systems, and systems requiring switch status verification for safety, operation, or process control purposes.