Document Number: MC33884
Rev. 4.0, 11/2006
Freescale Semiconductor
Technical Data
Switch Monitor Interface
The 33884 Switch Monitor Interface is a monolithic silicon integrated
circuit (IC) to perform switch monitoring functions. The device provides
efficient interface between electrical switches and low voltage
microprocessors. The 33884 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.
33884
SWITCH MONITOR INTERFACE
There are four modes of operation: Sleep, Normal, Polling, and
Polling + INT Timer.
The Polling and Timer modes are similar, except the Timer mode
has the addition of an interrupt that is sent to the microprocessor if a
switch is sensed closed, or upon the internal interrupt timer times out.
An interrupt is ultimately sent to the microprocessor. All modes of
operation are easily programmed via the Serial Peripheral Interface
(SPI) control.
DW SUFFIX
EG (PB-FREE) SUFFIX
98ASB42344B
24-PIN SOICW
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
• Interface Directly to Microprocessors Using SPI Protocol
• Wake Up on Change of Monitored Switch Status
• Programmable Wetting Current
ORDERING INFORMATION
Temperature
Device
Package
Range (T )
A
MC33884DW/R2
MCZ33884EG/R2
-40°C to 105°C
24 SOICW
• Four Switch-to-Ground Switches
• Six (Fixed Function) Inputs Monitoring Six Switch-to-Ground
Switches
• Two (Fixed Function) Inputs Monitoring Two Switch-to-Battery Switches
• Quiescent Current in Sleep Mode < 10 µA
• Reset Input Defaults the Device to Sleep Mode
• Pb-Free Packaging Designated by Suffix Code EG
V
PWR
V
33884
DD
VPWR
VDD
MCU
VDD
SB1
SB2
2 V
Sense Inputs
PWR
CS
CS
SI
SP1
SP2
SP3
SP4
MOSI
MISO
CLK
SO
SCLK
INT
4 GND / V
PWR
INT
Sense Inputs
RESET
GND
VBG
RESET
GND
SG1
SG2
SG3
SG4
SG5
SG6
SYNC
MASL
6 GND
Sense Inputs
Figure 1. 33884 Simplified Application Diagram
Freescale Semiconductor, Inc. reserves the right to change the detail specifications, as
may be required, to permit improvements in the design of its products.
© Freescale Semiconductor, Inc., 2006. All rights reserved.