33972_09 Datasheet, PDF (1/32 Pages) Freescale Semiconductor, Inc – Multiple Switch Detection Interface with Suppressed Wake-up

Freescale Semiconductor
Technical Data
Document Number: MC33972
Rev. 16.0, 10/2009
Multiple Switch Detection
Interface with Suppressed
Wake-up
33972/A/T
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 pin 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 pull-up or pull-down 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 ≤ V_PWR ≤ 26 V
• Switch input voltage range -14 V to V_PWR, 40 V Max
• Interfaces directly to MPU using 3.3 V/5.0 V SPI protocol
• Selectable wake-up on change of state
• Selectable wetting current (16 or 2.0 mA)
• 8 programmable inputs (switches to battery or ground)
• 14 switch-to-ground inputs
• Typical standby current - V_{PWR =} 100 μA and V_DD = 20 μA
• Active interrupt (INT) on change-of-switch state
• Pb-free packaging designated by suffix code EW
• Exposed pad packaging designated by suffix code EK
MULTIPLE SWITCH
DETECTION INTERFACE
DWB SUFFIX
EW SUFFIX (Pb-FREE)
98ARH99137A
32-PIN SOICW
EK SUFFIX (Pb-FREE)
98ASA10556D
32-PIN SOICW EP
ORDERING INFORMATION
Device
Temperature
Range (T_A)
Package
MC33972DWB/R2
MC33972EW/R2
MCZ33972EW/R2
MCZ33972AEW/R2
-40°C to 125°C
MC33972TDWB/R2
32 SOICW
MC33972TEW/R2
MCZ33972TEW/R2
MCZ33972AEK/R2
32 SOICW EP
VDD
VBAT
VBAT
33972
SP0
VPWR
SP1
VDD
SP7
WAKE
SG0
SG1
SG12
SG13
SI
SCLK
CS
SO
INT
AMUX
GND
VBAT
VDD
POWER SUPPLY
LVI
ENABLE
MCU
MOSI
SCLK
CS
MISO
INT
AN0
WATCHDOG
RESET
Figure 1. 33972 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., 2009. All rights reserved.