The MC33884 Switch Monitor Interface is a monolithic silicon
integrated circuit (IC) that performs switch monitoring functions.
The device provides efficient interface between electrical switches
and low voltage microprocessors. The MC33884 supplies switch
contact pull–up and pull–down current while monitoring the input
voltage level. All inputs are protected for transients when
implemented with an appropriate static discharge capacitor used
on the inputs.
There are four modes of operation – Sleep, Normal, Polling, and
Polling + INT Timer. Sleep mode reduces the current drain to a
quiescent current level of 10 A and disables the IC. Normal mode
interrupts the microprocessor whenever any external switch
changes it’s OPEN or CLOSED state. Polling mode reads a switch
status periodically and interrupts the microprocessor only when an
external switch is sensed as being CLOSED. The Polling + INT
Timer mode is similar to the Polling mode, with the addition of an
interrupt being sent to the microprocessor if a switch is sensed
CLOSED or upon the internal interrupt timer ”timing out”. An
interrupt is always ultimately sent to the microprocessor in this
mode. All modes of operation are easily programmed via the Serial
Peripheral Interface (SPI) control.
The MC33884 has the following features:
Full Operation with 7.0 V
≤
VPWR
≤
26 V,
Limited Operation with 5.5 V
≤
VPWR
≤
7.0 V
Input Voltage Range: –14 V to 40 V
Interfaces Directly to Microprocessors Using SPI Protocol
24–Lead Wide Body SOIC Package
Wake–up on Change of Monitored Switch Status
Programmable Wetting Current
4 Programmable Inputs to Monitor 4 Switch–to–Battery or
4 Switch–to–Ground Switches
6 (fixed function) Inputs to Monitor 6 Switch–to–Ground Switches
2 (fixed function) Inputs to Monitor 2 Switch–to–Battery Switches
Standby Current During Normal Mode = 100 A
Quiescent Current in Sleep Mode < 10 A
Reset (RST) Input Defaults the Device to Sleep Mode
Active Interrupt (INT) on Change of Switch State in Normal Mode
4 Modes of Operation
(Sleep, Normal, Polling, Polling + INT Timer)
Designed to Operate –40
°
C
≤
TA
≤
105
°
C
This document contains information on a new product. Specifications and information herein are subject to change without notice.
Order this document
by MC33884/D
SEMICONDUCTOR TECHNICAL DATA
Motorola, Inc. 2001
REV 2
09/01
PIN CONNECTIONS
DW Suffix
24 Lead SOIC
CASE 751E
SCALE 1:1
1
2
3
4
5
6
7
8
9
10
11
12
23
22
21
20
19
18
17
16
15
14
13
24
CSB
VBG
SP4
SG6
SG5
SG4
SB2
SP3
INTB
SYNC
RSTB
SCLK
SO
SI
SP1
SG1
SG2
SG3
SB1
SP2
MASL
VPWR
GND
VDD
Device
Operating
Temperature
Range
TA = – 40 to
105
°
C
TA = – 40 to
105
°
C
Package
ORDERING INFORMATION
MC33884DW
SO–24
MC33884DWR2
SO–24
