MCZ33975EK Freescale Semiconductor, MCZ33975EK Datasheet - Page 16

• Manufacturer Part Number: MCZ33975EK
• Description: IC DETECTOR MULT SWITCH 32-SOIC
• Manufacturer: Freescale Semiconductor

Specifications of MCZ33975EK

• Applications: Automotive
• Interface: SPI
• Voltage - Supply: 5.5 V ~ 28 V
• Package / Case: 32-SOIC (7.5mm Width) Exposed Pad, 32-eSOIC, 32-HSOIC
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 6. Settings Command
POWER SUPPLY
the VPWR pin. Characteristics are provided from 8.0V to 28V
for the device. Switch contact currents and the internal logic
supply are generated from the VPWR pin. The VDD supply
pin is used to set the SPI communication voltage levels,
current source for the SO driver, and pull-up current on
and
quiescent current. If VDD is removed while the device is in
Normal Mode, the device will remain in Normal Mode. If VDD
is removed in Sleep Mode, the device will remain in Sleep
Mode until a wake-up input is received (
switch input or interrupt timer expires).
communication and will not allow the device to wake up from
the
Sleep Mode. A discussion on Normal Mode begins below. A
discussion on
NORMAL MODE
of the 33975 be programmed through the SPI.
are listed below. Further explanation of each register is
provided in subsequent paragraphs.
16
33975
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
23
0
The 33975 is designed to operate from 5.5V to 38/40V on
VDD supply may be removed from the device to reduce
Removing VDD from the device disables SPI
The 33975 has two operating modes, Normal Mode and
Normal Mode may be entered by the following events:
• Application of VPWR to the IC
• Change-of-switch state (when enabled)
• Falling edge of
• Falling edge of
• Falling edge of
• Interrupt timer expires
Only in Normal Mode with VDD applied can the registers
The registers that may be programmed in Normal Mode
•
•
•
•
INT
CS
Logic [1])
Programmable Switch Register
Wake-up/Interrupt Register
Command)
Wetting Current Register
Wetting Current Timer Register
Enable Command)
22
.
0
and
Settings Command
21
CS
0
Sleep Mode
pins.
20
0
WAKE
INT
CS
19
0
(with VDD = 5.0V)
(with VDD = 5.0V and
begins on page 22.
18
0
(Metallic Command)
17
(Wake-up/Interrupt
0
(Wetting Current Timer
(Settings Command)
FUNCTIONAL DEVICE OPERATION
16
1
WAKE
15
X
high to low,
WAKE
14
OPERATIONAL MODES
X
at
13
X
INT
Not used
12
X
11
X
POWER-ON RESET (POR)
Reset and place the device in Normal Mode.
Reset Command are as follows:
has occurred by placing a logic [1] in bit 22 of the SO buffer.
The reset bit is cleared on rising edge of CS.
operation in Normal Mode. Switch states are latched into the
input register on the falling edge of
is cleared on the rising edge of CS. However,
clear on the rising edge of
SPI communication (
from being missed by the MCU.
PROGRAMMABLE SWITCH REGISTER
battery or switch-to-ground. These inputs types are defined
using the settings command (refer to
input for switch-to-battery, a logic [1] for the appropriate bit
must be set. To set an SPn input for switch-to-ground, a
logic [0] for the appropriate bit must be set. The MCU may
change or update the Programmable Switch Register via
software at any time in Normal Mode. Regardless of the
setting, when the SPn input switch is closed a logic [1] will be
placed in the Serial Output Response Register (refer to
Table
Applying VPWR to the device will cause a Power-ON
Default settings from Power-ON Reset via a VPWR or
• Programmable switch – Set to switch-to-battery
• All inputs set as wake-up
• Wetting current on (16mA pull-down, 32mA pull-up)
• Wetting current timer on (20ms)
• All inputs tri-state
• Analog select 00000 (no input channel selected)
Note The 33975 device provides indication that a reset
•
•
•
•
Figure
Inputs SP0 to SP7 may be programmable for switch-to-
10
X
Tri-state Register
Analog Select Register
Calibration of Timers
Reset
17, page 21).
X
9
6, page 11, is a graphical description of the device
(Reset Command)
X
8
sp7 sp6 sp5 sp4 sp3 sp2 sp1 sp0
7
CS
Analog Integrated Circuit Device Data
(Tri-state Command)
low). This prevents switch states
6
CS
(Calibration Command)
Battery/Ground Select
(Analog Command)
if a switch has closed during
5
Freescale Semiconductor
CS
4
Table
. The
3
6). To set an SPn
INT
INT
2
to the MCU
will not
1
0