MCZ33993EW Freescale Semiconductor, MCZ33993EW Datasheet - Page 14

• Manufacturer Part Number: MCZ33993EW
• Description: IC MULTIPLE SWITCH DETECT 32SOIC
• Manufacturer: Freescale Semiconductor

Specifications of MCZ33993EW

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 32-SOIC (7.5mm Width)
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 9. Tri-State Command
WETTING CURRENT TIMER REGISTER
starts when the specific switch input crosses the comparator
threshold (4.0 V). When the 20 ms timer expires, the contact
current is reduced from 16 mA to 2.0 mA. The wetting current
timer may be disabled for a specific input. When the timer is
disabled, 16 mA of current will continue to flow through the
Table 8. Wetting Current Timer Enable Command
TRI-STATE REGISTER
node as high impedance (refer to
Tri-State Register bit to logic [1], the input will be high
impedance regardless of the metallic command setting. The
ANALOG SELECT REGISTER
MCU using the analog command (refer to
to the IC is a 22-to-1 analog multiplexer. The voltage present
on the selected input pin is buffered and made available on
the AMUX output pin. The AMUX output pin is clamped to a
maximum of V
present on the input pin. After an input has been selected as
the analog, the corresponding bit in the next SO data stream
will be logic [0]. When selecting a channel to be read as
analog, the user must also set the desired current (16 mA,
2.0 mA, or high impedance). Setting bit 6 and bit 5 to 0,0
14
Table 7. Metallic Command
33993
FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
23
23
23
0
0
0
0
0
0
Each switch input has a designated 20 ms timer. The timer
The tri-state command is use to set the SPn or SGn input
The analog voltage on switch inputs may be read by the
Wetting Current Timer Commands
22
22
22
0
0
0
0
0
0
Tri-State Commands
Metallic Command
21
21
21
0
0
0
0
0
0
DD
20
20
20
0
0
0
0
0
0
volts regardless of the higher voltages
19
19
19
0
0
0
1
1
1
18
18
18
1
1
0
0
1
0
17
17
17
0
0
1
0
0
1
Table
16
16
16
0
1
1
0
1
0
9). By setting the
15
Table
15
15
X
X
X
X
X
X
14
14
14
X
X
X
X
X
X
10). Internal
sg1
sg1
sg1
13
13
13
X
3
X
3
X
3
sg1
12
sg1
sg1
X
12
12
2
X
2
X
2
sg1
11
sg1
sg1
X
1
11
11
X
1
X
1
closed switch contact. With multiple wetting 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
comparator on each input remains active. This command
allows the use of each input as a comparator with a 4.0 V
threshold. The MCU may change or update the Tri-State
Register via software at any time in Normal mode.
selects the input as high impedance. Setting bit 6 and bit 5 to
0,1 selects 2.0 mA, and 1,0 selects 16 mA. Setting bit 6 and
bit 5 to 1,1 in the Analog Select Register is not allowed and
will place the input as an analog input with high impedance.
currents for all SGn and SPn inputs (refer to
analog command does not allow pull-down currents on the
SPn inputs. Setting the current to 16 mA or 2.0 mA may be
useful for reading sensor inputs. Further information is
provided in the
beginning on page 20. The MCU may change or update the
sg1
10
sg1
sg1
X
0
The MCU may change or update the Wetting Current
Analog currents set by the analog command are pull-up
10
10
X
0
X
0
sg9
sg9 sg8 sg7 sg6 sg5 sg4 sg3 sg2 sg1 sg0
9
X
sg9 sg8 sg7 sg6 sg5 sg4 sg3 sg2 sg1 sg0
X
9
X
9
Command Bits
Command Bits
Command Bits
sg8
X
8
8
X
8
X
Typical Applications
sp7
sg7
sp7 sp6 sp5 sp4 sp3 sp2 sp1 sp0
sp7 sp6 sp5 sp4 sp3 sp2 sp1 sp0
7
7
7
Analog Integrated Circuit Device Data
sp6
sg6
6
6
6
sp5
sg5
5
5
5
sp4
sg4
Freescale Semiconductor
4
section of this datasheet
4
4
sp3
sg3
3
3
3
Table
Table
sp2
sg2
2
2
2
sp1
sg1
8).
10). The
1
1
1
sp0
sg0
0
0
0