33975 Datasheet, PDF (1/32 Pages) Freescale Semiconductor, Inc – Multiple Switch Detection Interface with Suppressed Wake-Up and 32mA Wetting Current

Freescale Semiconductor
Technical Data
Document order number: MC33975
Rev 4.0, 08/2005
Multiple Switch Detection
Interface with Suppressed
Wake-Up and 32mA Wetting
Current
Freescale offers multiple Switch Detection Interface Devices. The
33975 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.
33975
33975A
MULTIPLE SWITCH
DETECTION INTERFACE WITH
SUPPRESSED WAKE-UP
The 33975 device 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 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.
Improvements are a programmable interrupt timer for Sleep mode
that can be disabled, switch detection currents of 32 mA and 4.0 mA
for switch-to-ground inputs, and an interrupt bit that can be reset.
EK Suffix (Pb-Free)
98ARL10543D
32-TERMINAL SOICW EP
Features
ORDERING INFORMATION
• Designed to Operate 5.5 V ≤ V_PWR ≤ 28 V
• Switch Input Voltage Range -14 V to V_PWR
• Interfaces Directly to Microprocessor Using 3.3 V/5.0 V SPI
Device
MC33975EK/R2
Protocol
• Selectable Wake-Up on Change of State
PC33975AEK/R2
• Selectable Wetting Current (32 mA or 4.0 mA for switch-to-ground
inputs)
• 8 Programmable Inputs (Switches to Battery or Ground)
• 14 Switch-to-Ground Inputs
• V_PWR Standby Current 100 µA Typical, V_DD Standby Current 20 µA Typical
• Pb-free 32-terminal suffix EK
Temperature
Range (T_A)
-40°C to 125°C
Package
32 SOICW-EP
VDD
VBAT
VBAT
VBAT
33975
SP0
VPWR
SP1
VDD
SP7
SG0
SG1
SG12
WAKE
SI
SCLK
CS
SO
INT
AMUX
VDD
Power Supply
LVI
Enable
Watchdog
Reset
MCU
MOSI
SCLK
CS
MISO
INT
AN0
SG13
GND
Figure 1. 33975 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2005. All rights reserved.