SEMICONDUCTOR TECHNICAL DATA
Document order number: MC33993/D
Rev 2.0, 07/2003
Multiple Switch Detection Interface
The 33993 Multiple Switch Detection Interface 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 pin for the MCU to read.
The 33993 device has two modes of operation, Sleep and Normal. The Sleep
mode provides low quiescent current and enables the wake-up features of the
device. Normal mode allows programming of the device and supplies switch
contacts with pull-up or pull-down current as it monitors switch change of state.
The 33993 is packaged in the 32-pin wide-body SOIC, reducing circuit board
area. Low quiescent current makes the 33993 ideal for automotive and industrial
products requiring low sleep state currents. The internal block diagram of the
33993 is illustrated in Figure 1, page 2.
• 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
MC33993DWB/R2 -40°C to 125°C 32 SOICW
33993 Simplified Application Diagram
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Motorola, Inc. 2003