Μultiple Switch Detection interface with Suppressed Wake-Up

The 33972 Multiple Switch Detection Interface with Suppressed Wake-Up 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). The device also features a 22-to-1 analog multiplexer for reading inputs as analog. The analog input signal is buffered and provided on the AMUX output terminal for the MCU to read.

The 33972 device has two modes of operation, Normal and Sleep. Normal mode allows programming of the device and supplies switch contacts with pullup or pulldown current as it monitors switch change of state. The Sleep mode provides low quiescent current, which makes the 33972 ideal for automotive and industrial products requiring low sleep state currents.

Features

• Designed to Operate 5.5 V ≤ VPWR ≤ 26 V

• Switch Input Voltage Range -14 V to VPWR, 40 V Max

• Interfaces Directly to Microprocessor Using 3.3 V/5.0 V SPI Protocol

• Selectable Wake-Up on Change of State

• Selectable Wetting Current (16 mA or 2.0 mA)

• 8 Programmable Inputs (Switches to Battery or Ground)

• 14 Switch-to-Ground Inputs

• VPWR Standby Current 100 µA Typical, VDD Standby Current 20 µA Typical

• Active Interrupt (INT) on Change-of-Switch State

• Pb-Free Packaging Designated by Suffix Code EW