MCZ33975EK Freescale Semiconductor, MCZ33975EK Datasheet - Page 17

• 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

WAKE-UP/INTERRUPT REGISTER
allowed to wake the 33975 from Sleep Mode or set the
pin low in Normal Mode. Programming the wake-up/interrupt
bit to logic [0] will disable the specific input from generating
an interrupt and will disable the specific input from waking the
IC in Sleep Mode (refer to
WETTING CURRENT REGISTER
current, 32mA and 4.0mA, and two levels of switch-to-battery
contact current, 16mA and 2.0mA (see
metallic command is used to set the switch contact current
level (refer to
logic [0] will set the switch wetting current to 2.0mA/4.0mA.
Programming the metallic bit to logic [1] will set the switch
contact wetting current to 16mA/32mA. The MCU may
change or update the Wetting Current Register via software
at any time in Normal Mode.
current during switch closure. The higher level of current is
designed to keep switch contacts from building up oxides that
form on the switch contact surface.
WETTING CURRENT TIMER REGISTER
starts when the specific switch input crosses the comparator
threshold (4.0V). When the 20ms timer expires, the contact
current is reduced from 16mA to 2.0mA for switch-to-battery
inputs and 32mA to 4.0mA for switch-to-ground inputs. The
wetting current timer may be disabled for a specific input.
When the timer is disabled, wetting current will continue to
flow through the closed switch contact. With multiple wetting
Table 7. Wake-Up /Interrupt Command
Analog Integrated Circuit Device Data
Freescale Semiconductor
23
23
0
0
0
0
The Wake-up/Interrupt Register defines the inputs that are
The 33975 has two levels of switch-to-ground contact
Wetting current is designed to provide higher levels of
Each switch input has a designated 20ms timer. The timer
22
22
0
0
Wake-up/Interrupt Command
0
0
21
Metallic Command
21
0
0
0
0
Table
20
20
0
0
0
0
8). Programming the metallic bit to
19
19
0
0
0
0
Table
18
18
1
1
0
0
7). Programming the wake-
17
17
0
0
1
1
16
16
0
1
0
1
Figure
15
15
X
X
X
X
11). The
Table 8. Metallic Command
14
14
X
X
X
X
sg1
sg1
13
13
X
X
3
3
INT
sg1
sg1
12
12
X
X
2
2
sg1
sg1
11
11
X
X
1
1
up/interrupt bit to logic [1] will enable the specific input to
generate an interrupt with switch change of state and will
enable the specific input as wake-up. The MCU may change
or update the Wake-up/Interrupt Register via software at any
time in Normal Mode.
current timers disabled, power dissipation for the IC must be
considered.
Timer Register via software at any time in Normal Mode. This
allows the MCU to control the amount of time wetting current
is applied to the switch contact. Programming the wetting
current timer bit to logic [0] will disable the wetting current
timer. Programming the wetting current timer bit to logic [1]
will enable the wetting current timer (refer to
The MCU may change or update the Wetting Current
sg1
sg1
10
10
X
0
X
0
Figure 11. Contact Wetting and Sustain Current
sg9 sg8 sg7 sg6 sg5 sg4 sg3 sg2 sg1 sg0
sg9 sg8 sg7 sg6 sg5 sg4 sg3 sg2 sg1 sg0
X
9
X
9
Command Bits
Command Bits
Switch Contact Voltage
X
8
X
8
for Switch-to-Ground Input
20 ms Wetting Current Timer
sp7 sp6 sp5 sp4 sp3 sp2 sp1 sp0
sp7 sp6 sp5 sp4 sp3 sp2 sp1 sp0
7
7
32 mA Switch Wetting Current
4.0 mA Switch Sustain Current
6
6
FUNCTIONAL DEVICE OPERATION
5
5
4
4
OPERATIONAL MODES
3
3
Table
2
2
9).
1
1
33975
0
0
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