MOTOROLA MC33884DW

MOTOROLA
Order this document
by MC33884/D
SEMICONDUCTOR TECHNICAL DATA
Advance Information
Switch Monitor Interface
The MC33884 Switch Monitor Interface is a monolithic silicon
integrated circuit (IC) that performs switch monitoring functions.
The device provides efficient interface between electrical switches
and low voltage microprocessors. The MC33884 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.
There are four modes of operation – Sleep, Normal, Polling, and
Polling + INT Timer. Sleep mode reduces the current drain to a
quiescent current level of 10 mA and disables the IC. Normal mode
interrupts the microprocessor whenever any external switch
changes it’s OPEN or CLOSED state. Polling mode reads a switch
status periodically and interrupts the microprocessor only when an
external switch is sensed as being CLOSED. The Polling + INT
Timer mode is similar to the Polling mode, with the addition of an
interrupt being sent to the microprocessor if a switch is sensed
CLOSED or upon the internal interrupt timer ”timing out”. An
interrupt is always ultimately sent to the microprocessor in this
mode. All modes of operation are easily programmed via the Serial
Peripheral Interface (SPI) control.
The MC33884 has the following 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
• Interfaces Directly to Microprocessors Using SPI Protocol
• 24–Lead Wide Body SOIC Package
• Wake–up on Change of Monitored Switch Status
• Programmable Wetting Current
• 4 Programmable Inputs to Monitor 4 Switch–to–Battery or
4 Switch–to–Ground Switches
• 6 (fixed function) Inputs to Monitor 6 Switch–to–Ground Switches
• 2 (fixed function) Inputs to Monitor 2 Switch–to–Battery Switches
• Standby Current During Normal Mode = 100 mA
• Quiescent Current in Sleep Mode < 10 mA
• Reset (RST) Input Defaults the Device to Sleep Mode
• Active Interrupt (INT) on Change of Switch State in Normal Mode
• 4 Modes of Operation
(Sleep, Normal, Polling, Polling + INT Timer)
• Designed to Operate –40°C ≤ TA ≤ 105°C
MC33884
SCALE 1:1
DW Suffix
24 Lead SOIC
CASE 751E
PIN CONNECTIONS
VDD
SO
SI
SP1
SG1
SG2
SG3
SB1
SP2
MASL
VPWR
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
SCLK
CSB
VBG
SP4
SG6
SG5
SG4
SB2
SP3
INTB
SYNC
RSTB
ORDERING INFORMATION
Operating
Temperature
Range
Package
MC33884DW
TA = – 40 to
105°C
SO–24
MC33884DWR2
TA = – 40 to
105°C
SO–24
Device
This document contains information on a new product. Specifications and information herein are subject to change without notice.
REV 2
09/01
 Motorola, Inc. 2001
t
MC33884
SP1
SP2
SP3
SP4
Switch–to–Ground
and
Switch–to–Battery
Sense Inputs
(x4)
SG1
SG2
SG3
SG4
SG5
SG6
Switch–to–Ground
Sense Inputs
(x6)
SB1
SB2
Programmable Input Blocks (1–4)
Metallic or Non–metallic
Enable or Disable Input Block (Tri–State)
Fixed Input Blocks
GND (1–6)
SPI Decode
Switch–Ground, Metallic or Non–metallic,
Enable or Disable FIB (Tri–State)
PIB Configure, FIB/PIB Tri–State
FIB/PIB Metallic
Fixed Input Blocks
Battery (1–2)
Switch–to–Battery
Sense Inputs
(x2)
Switch–Batt, Metallic or Non–metallic,
Enable or Disable FIB (Tri–State)
SPI Interface
CSB
SI
SO
SCLK
SPI Encode
Mode Switch Status
V DD
VPWR
V SS
VDD, V+
Distribution
(To all input blocks)
Quiescent
Current
Control
Mode Control
Normal, Polling, Sleep
INTB
Polling Mode
V BG
Oscillator
RSTB
Wake–up
Slave Sync
SYNC
Master/Slave Select
MASL
Figure 1. Internal Block Diagram
2
MOTOROLA TSG IC DEVICE DATA
MC33884
External
Switches
V PWR
V DD
V BAT T
V PWR
SB1
V BAT T
10 nF
0805
100 V
10 nF
0805
100 V
SB2
V BAT T
10 nF
0805
100 V
SP1
10 nF
0805
100 V
MC33884
10 nF
0805
100 V
V BAT T
SP2
V BAT T
10 nF
0805
100 V
10k
0805
SI
MOSI
SO
MISO
SCLK
SP3
V BAT T
MC68HCXX
Microcontroller
V DD
M
S
B
L
S
B
Parallel
Ports
INTB
10 nF
0805
100 V
16 Bit Shift Register
CSB
SP4
10 nF
0805
100 V
10 nF
0805
100 V
V BG
SG1
RESET
130k
0805
SG2
10 nF
0805
100 V
10k
0805
SG3
10 nF
0805
100 V
RSTB
SG4
WDOG
LVI
RESET Control
10 nF
0805
100 V
SG5
10 nF
0805
100 V
MASTER
NODE
SYNC
SG6
V BAT T
10 nF
0805
100 V
SYNC
SB1
V BAT T
MASL
SLAVE
NODE
10 nF
0805
100 V
V PWR
10 nF
0805
100 V
SB2
V BAT T
10 nF
0805
100 V
SP1
MC33884
V DD
10 nF
0805
100 V
10 nF
0805
100 V
V BAT T
SP2
V BAT T
10 nF
0805
100 V
SP3
V BAT T
10 nF
0805
100 V
SI
SO
SCLK
INTB
CSB
RSTB
MASL
V BG
SP4
10 nF
0805
100 V
130k
0805
Figure 2. Typical Master / Slave Application
MOTOROLA TSG IC DEVICE DATA
3
MC33884
Pin Function Description
4
Pin
Name
Description
1
VDD
2
SO
SPI Data Out Pin
3
SI
SPI Data In Pin
4
SP1
Programmable – Switch–to–Battery or Switch–to–Ground Input 1 (Source or Sink Output)
5
SG1
Switch–to–Ground Input 1 (Source Output)
6
SG2
Switch–to–Ground Input 2 (Source Output)
7
SG3
Switch–to–Ground Input 3 (Source Output)
8
SB1
Switch–to–Battery Input 1 (Sink Output)
5.0 V Logic Supply
9
SP2
Programmable – Switch–to–Battery or Switch–to–Ground Input 2 (Source or SInk Output)
10
MASL
Master or Slave Select Pin – Used when multiple MC33884 devices are required in Module
11
VPWR
Conditioned Battery Supply Voltage
12
VSS
13
RSTB
Ground
Reset Input
14
SYNC
Synchronization Output – Used when multiple MC33884 devices are required in Module. Provide
synchronized wake–up of multiple MC33884 devices.
15
INTB
Interrupt – Open Drain Output
16
SP3
Programmable – Switch–to–Battery or Switch–to–Ground Input 3 (Source or Sink Output)
17
SB2
Switch–to–Battery Input 2 (Sink Output)
18
SG4
Switch–to–Ground Input 4 (Source Output)
19
SG5
Switch–to–Ground Input 5 (Source Output)
20
SG6
Switch–to–Ground Input 6 (Source Output)
21
SP4
Programmable – Switch–to–Battery or Switch–to–Ground Input 4 (Source or Sink Output)
22
VBG
Bandgap Voltage. A bandgap reference is used to set up the reference and bias currents for the device.
A resistor must be connected from this pin to ground.
23
CSB
Chip Select Input. Input with internal active pull–up. Requires 5.0 V CMOS logic levels. Communication
with the device using SPI is enabled when the CSB pin is a logic 0.
24
SCLK
Serial Clock. SCLK is used to shift data into and out of the device. It transitions 1 time per bit with an
operation frequency, fSCLK, with a 50% duty cycle. SCLK is idle between commands and should be
commanded low.
MOTOROLA TSG IC DEVICE DATA
MC33884
MAXIMUM RATINGS (All voltages are with respect to ground, unless otherwise noted)
Symbol
Value
Unit
VDD Supply Voltage
Rating
–
–0.3 to 7.0
VDC
CSB, SI, SO, SCLK, RSTB, MASL, SYNC, INTB (Note 1)
–
–0.3 to 7.0
VDC
VPWR Supply Voltage (Note 1)
–
–16 to 50
VDC
Switch Input Voltage Range
–
–14 to 40
VDC
Recommended Frequency of SPI Operation
–
3.0
MHz
VESD1
VESD2
4000
200
V
Storage Temperature
Tstg
–55 to 150
°C
Operating Case Temperature
TC
–40 to 105
°C
Operating Junction Temperature
TJ
–40 to 150
°C
TSolder
260
°C
–
–40 to 150
°C
PqJA
107
°C/W
ESD Voltage (Note 2)
Human Body Model (Notes 3, 4, 5)
Machine Model (Note 6)
Lead Soldering Temperature (Note 7)
Maximum Junction Temperature
Thermal Resistance, Junction–to–Ambient
Plastic Package, 24 SOIC, Case 751E:
NOTES:
1. Exceeding these limits may cause malfunction or permanent damage to the device.
2. ESD data available upon request.
3. ESD1 testing is performed in accordance with the Human Body Model (CZAP = 100 pF, RZAP = 1500
4. All pins when tested individually.
5. 1 kV on VPWR and VDD when connected together.
6. ESD2 testing is performed in accordance with the Machine Model (CZAP = 100 pF, RZAP = 0 W).
7. Lead soldering temperature limit is for 10 seconds maximum duration.
MOTOROLA TSG IC DEVICE DATA
W).
5
MC33884
STATIC ELECTRICAL CHARACTERISTICS (Characteristics noted under conditions of 4.75 V ≤ VDD ≤ 5.25 V, 9.0 V ≤ VPWR
≤ 16 V, –40°C ≤ TC ≤ 105°C, unless otherwise noted. Typical values, where applicable, reflect the parameter’s approximate
average value with VPWR = 13 V, TA = 25°C.)
Characteristic
Symbol
Min
Typ
Max
Units
Supply Voltage Range
Quasi–Functional (Note 1)
Fully Operational
VPWR(qf)
VPWR(fo)
5.5
7.0
–
–
7.0
26
Supply Current Normal Mode (IDD + IPWR) (All Switches Open)
IPWR(on)
–
100
300
mA
I(ss)
–
2.0
10
mA
–
26
–
mA
POWER INPUT
Supply Current Sleep State (IDD(SS) + IPWR(on))
V
Supply Current Periodic Mode (Polling at 30–50 ms period)
(All Switches Open)
Logic Supply Voltage
VDD
4.75
–
5.25
V
VBG
1.18
1.26
1.4
V
Pulse Wetting Current Switch to Battery
Iw(batt)
7.5
14
25
mA
Pulse Wetting Current Switch to Ground
Iw(gnd)
–7.5
–14
–25
mA
Sustain Current Switch to Battery
Is(batt)
0.4
0.75
1.25
mA
Sustain Current Switch to Ground
Is(gnd)
–0.4
–0.75
–1.25
mA
Tri–State Input Current
IT(swt)
–10
–
10
mA
Switch Detection Threshold
Ith
3.25
3.75
4.75
V
Switch Input Voltage Range
Vin
–14
–
40
V
Input Logic Voltage Thresholds (Note 2)
VIN(logic)
0.2 * VDD
–
0.7 * VDD
V
SO High State Output Voltage (IOH = 1 mA)
VOH(so)
3.5
–
–
V
SO Low State Output Voltage (IOL = 1 mA)
VOL(so)
–
–
0.4
V
IT(so)
–40
–
40
SI Pull–Down Current (SI = VDD)
ISI
5.0
–
35
SCLK Input Current (0 V = VDD)
ISCLK
–10
–
10
CSB Pull–Up Current (CSB = 0 V)
ICSB
–25
–
–5.0
IRSTB
5.0
–
35
–
–
0.4
V
–
–
20
pF
Bandgap Voltage Output Pin (Tested with 130 kW ± 0.1% resistor)
SWITCH INPUT
DIGITAL INTERFACE
SO Tri–State Leakage Current (CSB = 0.7 VDD, VSO = 0 to VDD)
RSTB Pull–Down Current (RSTB = 0 V)
INTB Low State Output Voltage (IOL = 0.5 mA)
Input Capacitance on SCLK, SI, Tri–State SO, CSB (Note 3)
VOL(INTB)
CIN
mA
mA
mA
mA
mA
NOTES:
1. SPI inputs and outputs are operational; Fault reporting may not be fully operational within this voltage range.
2. Upper and lower logic threshold voltage levels apply to SI, CSB, SCLK, RSTB, SYNC, MASL.
3. This parameter is guaranteed by design, but not production tested
6
MOTOROLA TSG IC DEVICE DATA
MC33884
DYNAMIC ELECTRICAL CHARACTERISTICS (Characteristics noted under conditions of 4.75 V ≤ VDD ≤ 5.25 V, 9.0 V ≤ VPWR ≤
16 V, –40°C ≤ TC ≤ 105°C, unless otherwise noted. Typical values, where applicable, reflect the parameter’s approximate
average value with VPWR = 13 V, TA = 25°C.)
Characteristics
Symbol
Min
Typ
Max
Units
tpulse
30
34
43
ms
tINT(delay)
2.5
–
13
ms
fSCLK
3.2
3.5
4.0
–
–
MHz
Falling Edge of CSB to Rising Edge of SCLK (Note 1)
(Required Set–up Time)
tlead
–
100
140
ns
Falling Edge of SCLK to Rising Edge of CSB
(Required Set–up Time)
tlag
–
–
50
ns
tSU2
–
25
45
ns
tH2
–
25
45
ns
tSU1
90
125
–
ns
tH1
90
125
–
ns
SO Rise Time, SO Fall Time (CL = 200 pF)
tr(SO)
tf(SO)
–
30
50
ns
SI, CSB, SCLK Incoming SIgnal Rise Time (Note 2)
tr(SI)
–
–
50
ns
SI, CSB, SCLK Incoming Signal Fall Time (Note 2)
tf(SI)
–
–
50
ns
Time from Falling Edge of CSB to SO Low Impedance (Note 3)
tSO(en)
–
80
110
ns
Time for Rising Edge of CSB to SO High Impedance (Note 4)
tSO(DIS)
–
80
110
ns
Time from Falling Edge of SCLK to SO Data Valid (Note 5)
tvalid
–
65
105
ns
Recovery Time for Sequential Transfers
tREC
–
100
120
ns
SWITCH INPUT
Pulse Wetting Current Duration
Interrupt Delay Time
SCLK Frequency vs. SO Load Capacitance
200 pF
160 pF
120 pF
DIGITAL INTERFACE TIMING
SI to Rising Edge of SCLK (Required Set–up Time)
Rising Edge of SCLK to SI (Required Hold Time)
SO to Rising Edge of SCLK (Required Set–up Time)
Rising Edge of SCLK to Falling Edge of SO (Hold Time)
NOTES:
1. This parameter is guaranteed by design, but not production tested.
2. Rise and Fall time of incoming SI, CSB, and SCLK signals suggested for design consideration to prevent the occurrence of double pulsing.
3. Time required for output status data to be available for use at SO pin.
4. Time required for output states data to be terminated at SO pin.
5. Time required to obtain valid data out from SO following the falling edge of SCLK.
MOTOROLA TSG IC DEVICE DATA
7
MC33884
tLEAD
CSB
tWH
fSCK
tLAG
SCLK
tWL
tSOEN
tSU1
tVALID
tSODIS
tH1
SO
tH2
tSU2
SI
Figure 3. SPI Timing Diagram
8
MOTOROLA TSG IC DEVICE DATA
MC33884
CIRCUIT DESCRIPTION
Introduction
The MC33884 is a monolithic integrated circuit designed to
interface between external electrical system switches and low
voltage microprocessors via a Serial Peripheral Interface
(SPI). The MC33884 monitors the OPEN/CLOSED status of
multiple external switches used in a system. The MC33884
features 4 programmable Switch–to–Ground or Battery sense
inputs,
6
Switch–to–Ground
sense
inputs,
2
Switch–to–Battery sense inputs, programmable Wake–up
Timer, programmable Interrupt Timer, and programmable
wetting current settings. All inputs are protected for ESD
transients when implemented with the appropriate ESD
capacitor.
There are numerous applications for this device in aircraft,
aerospace, robotic, process & control, automotive, and
security systems. Potential applications exist where switch
status verification for safety, fault tolerant operation, or
process control function purposes are critical.
The MC33884 has four modes of operation: Sleep, Normal,
Polling, and Polling + INT Timer.
The MC33884 is designed to provide a robust interface
between system switch contacts and a microprocessor. Each
MC33884 input provides the switch contact with high levels of
wetting current during switch closure. After the input switch
has been closed for 20 ms, the wetting current is reduced,
hence reducing power dissipation in the IC. The response to
a SPI command will always return Switch Status,
Master/Slave, INT Flag, and Mode settings. The following
section describes the programming modes and features of the
MC33884.
Two or more MC33884 devices may be used in a module
system when implemented in a parallel or serial configuration.
Figure 5 and Figure 6 show the parallel and serial
configurations respectively.
When using the Serial
configuration, 32 clock cycles are required for a complete
transfer of data to the MC33884.
MC68HCXX
Microcontroller
MOSI
SI
16 Bit Shift Register
MC33884
MISO
SO
SCLK
SCLK
CS
Parallel
Ports
RSTB
INT
INTB
SI
MC33884
SO
SCLK
CS
RSTB
INTB
Microprocessor Interface
The MC33884 directly interfaces to 3.3 or 5.0 V MCU. SPI
serial clock frequencies in excess of 5.0 MHz may be used for
programming and reading switch input status. Figure 4 shows
the configuration between an MCU and one MC33884.
MC68HCXX
Microcontroller
MC33884
MOSI
Figure 5. SPI Parallel Interface with Microprocessor
MC68HCXX
Microcontroller
SI
MISO
SO
MC33884
SI
16 Bit Shift Register
SCLK
16 Bit Shift Register
MISO
MOSI
16 Bit Shift Register
CS
Parallel
Ports
SO
SCLK
RSTB
INT
INTB
SCLK
To
Logic
Receive
Buffer
Parallel
Ports
INT
RSTB
CS
INTB
SI
MC33884
SO
Figure 4. SPI Interface with Microprocessor
The MC33884, though originally designed for automotive
use, is very useful in a variety of other applications, i.e.,
computer, telecommunications, and industrial fields. It is
parametrically specified over an input battery/supply voltage
of 9.0 to 16.0 V but is designed to operate over a considerably
wider range of 5.5 to 26.5 V.
MOTOROLA TSG IC DEVICE DATA
SCLK
CS
RSTB
INTB
Figure 6. SPI Serial Interface with Microprocessor
9
MC33884
PIN FUNCTIONAL DESCRIPTION
CSB Pin
SYNC Pin
The system MCU selects the MC33884 to be
communicated with through the use of the CSB pin. With the
CSB in a logic low state, command words may be sent to the
MC33884 via SI and switch status can be received by the
MCU via SO. Falling edge of CSB enables the SO output,
latches the state of the INTB pin, operating mode and the state
of the external switch inputs. Rising edge of CSB disables the
SO driver, resets the INTB pin to logic [1], activates the
received command word, and allows the MC33884 to act upon
new data obtained from switch inputs. To avoid any spurious
data, it is essential that the high–to–low and low–to–high
transition of the CSB signal occur only when SCLK is in a logic
low state. Internal to the MC33884 is an active pull up on CSB.
The SYNC input is used by slave IC during Polling mode.
The SYNC allows multiple MC33884 ICs to poll the multiple
inputs at the same time. The Master controls the polling
period. The Slave is allowed to shut down it’s oscillator to
conserve current. When the Slave receives the SYNC signal
from the Master, the Slave starts the internal oscillator and
reads the switch inputs.
SCLK Pin
The system clock pin (SCLK) clocks the internal 16–bit shift
register of the MC33884. The serial input (SI) data is latched
into the input shift register on the rising edge of SCLK signal.
The serial output pin (SO) shifts the switch status bits out on
the falling edge of SCLK. False clocking of the shift register
must be avoided to guarantee validity of data. It is essential
that the SCLK pin be in a logic low state whenever chip select
pin (CSB) makes any transition. For this reason it is
recommended, though not necessary, that the SCLK pin be
commanded to a low logic state as long as the device is not
accessed (CSB in logic high state). When the CSB is in a logic
high state, any signal on the SCLK and SI pin will be ignored
and the SO pin is Tri–Stated (high impedance).
SI Pin
This pin is used for serial instruction data input. SI
information is latched into the input register on the rising edge
of SCLK. A logic high state present at SI when SCLK rises,
programs a [1] into the command word on rising edge of the
CSB signal. To program a complete word, 16 bits of
information must be entered into the MC33884. Internal to the
IC is an active pull down on the SI pin.
SO Pin
The serial output (SO) pin is the output from the shift
register. The SO pin remains Tri–State until the CSB pin
transitions to a logic low state. All “open switches” are
reported as [0], all ‘closed switches’ are reported as [1]. The
negative transition of CSB will make status bit 15 available on
SO. Each successive negative clock will make the next status
bit available. The SI/SO shifting of the data follows a
first–in–first–out protocol with both input and output words
transferring the Most Significant Bit (MSB) first.
MASL pin
The MASL pin is required when multiple MC33884 devices
are used in one module. The MASL (Master/Slave) identifies
which device will be the master and which will be the slave.
Master/Slave identification is used during Polling mode. In the
Polling mode the Master device has it’s internal oscillator
running while the Slave device oscillator is shutdown. When
polling the Master device wakes the Slave via the SYNC pin.
This feature provides minimal quiescent from VPWR and VDD
pins.
10
INTB Pin
The INTB pin is an interrupt output from the MC33884. The
INTB pin is an open drain output with an internal pull up. In
normal mode a switch state change will trigger the INTB pin.
The INTB pin and INT bit (flag) is latched on falling edge of
CSB. This permits the MCU to determine the origin of the
interrupt. The flag INT bit in the SPI word is the inverse of the
INTB pin. The INTB pin is cleared on rising edge of CSB. In
Polling mode the INTB pin is active only during the ON time
(when sink and source currents are active).
RSTB Pin
The RSTB pin is active low reset input to the MC33884.
When asserted, the MC33884 will reset all internal registers,
timers, and enter a sleep mode (with all switch inputs in a
Tri–State condition). Only an MCU SPI command word will
wake the MC33884 from a sleep state. The RSTB pin may be
controlled directly from a general purpose I/O pin or from a
system/MCU reset.
VBG Pin
The VBG pin requires a 130 kΩ to ground for standard
wetting and sustain currents. The device is tested with a 0.1%
value, but a standard 1.0% could be used for proper
functionality.
VPWR Pin
VPWR pin is battery/supply source pin for the MC33884.
The VPWR pin requires external reverse battery/supply and
transient protection. Maximum input voltage on VPWR is 40
volts. All wetting currents and sustain currents are derived
from VPWR.
SP1 – SP4 Pins
The MC33884 has 4 switch sense inputs that may be
programmed to read switch–to–ground or switch–to–battery/
supply contacts. Transient battery/supply voltages greater
than 40 volts must be clamped by an external device. Surface
mount 0805 MOVs and transient voltage suppressors (TVS)
are available in SOT–23 packages. The sensed input is
compared with an internal 4.0 volt reference. When
programmed to sense switch–to–battery, sensed voltages
greater than 4.0 volts are interpreted as a CLOSED switch.
Sensed voltages less than 4.0 V are interpreted as an OPEN
switch. The opposite holds true when inputs are programmed
to sense switch–to–ground. Further programming can set the
wetting currents or make the inputs Tri–State. Programming
methods are provided in the following section.
MOTOROLA TSG IC DEVICE DATA
MC33884
PIN FUNCTIONAL DESCRIPTION (continued)
SB1, SB2 Pins
SG1 – SG6 Pins
The SB pins are switch–to–battery sensing inputs only.
Transient battery/supply voltages greater than 40 volts must
be clamped by external device. Surface mount 0805 MOVs
and transient voltage suppressors (TVS) are available in
SOT–23 packages. The sensed input is compared with an
internal 4.0 volts reference. Voltages greater than 4.0 volts are
interpreted as a CLOSED switch. Sensed voltages less than
4.0 V are interpreted as an OPEN switch. Programming can
set wetting currents or Tri–State the input. Programming
methods are provided in the following section.
The SG pins are switch–to–ground inputs only. The input is
compared with the internal 4.0 volt reference. Voltages greater
than 4.0 volts are interpreted as an OPEN switch. Voltages
less than 4.0 V are interpreted as a CLOSED switch.
Programming can set the wetting currents or Tri–State the
input. Programming methods are provided in the following
section.
FUNCTIONAL DESCRIPTION
POWER UP
On initial power up, all MC33884 registers will be cleared
and the device will enter the Sleep mode. To exit Sleep mode
a valid command word is required to be received from the
microprocessor.
Sleep Command
Sleep mode can be entered by a SPI Sleep command or
asserting the RSTB pin. In Sleep mode all inputs are Tri–State
and all internal active pull up and pull down currents are
disabled. Sleep mode reduces the current drain to a quiescent
current level of 10 µA and disables the IC. Sleep mode
provides lowest quiescent current for the IC. Exit from sleep
mode requires a valid SPI RUN, TRI–STATE, or METALLIC
command.
RUN Command
Run command places the IC in one of three operating
modes; Normal, Polling, and Polling + INT Timer. The
command also programs the SP1 to SP4 sense inputs
(switch–to–battery [1] or switch–to–ground [0]). See Table 1.
Normal mode is the normal operating mode of the
MC33884. In Normal Mode the status of the input
switches are latched on falling edge of CSB and data is
sent back to MCU via SPI. All programmed
combinations of source and sink currents, used for
sensing purposes, are always active in this mode. In
normal mode an interrupt is generated and sent to the
microprocessor whenever an external switch changes
its OPEN or CLOSED state. Prior to a switch closing,
the MC33884 sources 0.75 mA of sustain current.
When the voltage at the input crosses the comparator
threshold, 14 mA of current is allowed to flow. The 14
mA wetting current shuts off after a 20 ms timer
expires.
Polling mode reads a switch status periodically and
interrupts the microprocessor only when an external
switch is sensed as being CLOSED. If the MC33884
senses all external switches to be OPEN, the Polling
mode of operation continues. If a switch is sensed
CLOSED, an interrupt is sent to the microprocessor
and the MC33884 transfers it’s operational mode to the
Normal mode. The Polling mode provides a reduction
in quiescent current by turning OFF all source and sink
currents during sensed switch OFF periods. The
MOTOROLA TSG IC DEVICE DATA
Polling mode allows the user to reduce quiescent
current by disabling sink and source currents during
swtich ”OFF” periods.
Polling + INT Timer mode of operation is similar to the
Polling mode above, with the addition of an interrupt
being sent to the microprocessor if a switch is sensed
CLOSED or upon the internal interrupt timer ”timing
out”. An interrupt is always ultimately sent to the
microprocessor in this mode. The microprocessor can
be programmed to read (or ignore) the MC33884’s
reported switch status upon receiving the interrupt. If a
switch is sensed CLOSED, operation reverts
automatically to the Normal mode. If all switches are
sensed OPEN, and the wake–up timer (INT Timer)
times out, the MC33884 continues to operate in the
Polling + INT Timer mode. The wake–up timer duration
may be set much longer than the Polling time.
TRI–STATE Command
TRI–STATE command places all switch inputs into
Tri–State. All comparators on inputs are disabled in this mode.
The device will return [0] for the switch status.
SPI PROGRAMMING
The MC33884 uses the SPI in full duplex synchronous slave
mode for communication with the microprocessor. The
MC33884 is programmed via a 16 bit word command from the
MCU. The word is sent to the device with the MSB first. The
command word sent to the MC33884 sets the mode of
operation in the device. Data received back from the
MC33884 is the status of the sensed input switch on falling
edge of CSB. Sixteen clock periods are required for each
transmission to be valid. After the 16 clocks, CSB is returned
to the inactive state (logic [1]), command words are no longer
accepted into SI, and the SO pin is Tri–Stated. The response
to a SPI command returns status based on previous command
word. This previous command could be a hardware reset as
well as any of the other commands discussed in this section.
11
MC33884
PROGRAMMING AND CONFIGURATION DESCRIPTION
SPI Commands from Microcontroller
Command Protocol (Data into SI)
Table 1: SPI Command Protocol
MSB
Bit
Command
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Sleep [DEFAULT]
0
0
0
0
X
X
X
Run
0
0
0
1
MOD2
MOD1
ST3
X
X
X
X
X
X
X
X
X
ST2
ST1
–
WT2
WT1
CP4
CP3
CP2
CP1
Tri–State
0
0
1
1
TG6
TG5
TG4
TG3
TG2
TG1
TP4
TP3
TP2
TP1
TB2
TB1
Metallic
0
1
0
1
MG6
MG5
IC Test Mode
1
X
X
X
X
X
MG4
MG3
MG2
MG1
MP4
MP3
MP2
MP1
MB2
MB1
X
X
X
X
X
X
X
X
X
X
Run Register
—
—
—
—
U
U
U
U
U
U
U
U
U
U
U
U
Tri–State Register
—
—
—
—
0
0
0
0
0
0
0
0
0
0
0
0
Metallic Register
—
—
—
—
U
U
U
U
U
U
U
U
U
U
U
U
RESET VALUES:
U: Unknown value coming out of Sleep mode; must configure with Run and Metallic commands.
NOTE: the remaining combinations of Bits [16:13] are NON–FUNCTIONAL (0010, 0100, 0110, 0111)
LABEL DEFINITIONS
MOD[2:1]
Operating Mode
ST[3:1]
Sample OFF Time
CP[4:1]
TG[6:1]
Configure Programmable Switch
WT[3:1]
Wake–Up Time
Tri–State Switch–to–Ground
MG[6:1]
Metallic Switch–to–Ground
TB[2:1]
Tri–State Switch–to–Battery
MB[2:1]
Metallic Switch–to–Battery
TP[4:1]
Tri–State Programmable Switch
MP[4:1]
Metallic Programmable Switch
Sleep Command
The Sleep command places the IC in Sleep mode and essentially turns off the part. By definition, a hardware reset sends/keeps
the IC in Sleep mode. All inputs are Tri–Stated, disabling all input blocks and all internal pull–ups/pull–downs. Only a SPI command
can take the IC out of Sleep mode. Exiting this mode requires a valid Run, Tri–State, or Metallic command.
MSB
Bit
Command
Sleep [DEFAULT]
12
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
X
X
X
X
X
X
X
X
X
X
X
X
MOTOROLA TSG IC DEVICE DATA
MC33884
DESCRIPTION (Continued)
Run Command
The Run command gives access to all of the operating modes: Normal, Polling, and Polling + INT Timer. It allows selection of
tWAIT and tWAKE, and configures the programmable input blocks. Bit 7 is currently unused. Note that the Run register values are
unknown after exiting the Sleep mode.
MSB
Bit
Command
Run
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
1
MOD2
MOD1
ST3
ST2
ST1
–
WT2
WT1
CP4
CP3
CP2
CP1
—
—
—
—
U
U
U
U
U
U
U
U
U
U
U
U
RESET VALUES:
Run Register
U: Unknown value coming out of Sleep mode; must configure with Run command.
MOD[2:1] — Operating Mode
In the Run command, the two MOD bits place the device in one of three operating modes: Normal, Polling, and Polling + INT
Timer.
Bit Definitions for Run Command
COMMAND: Run (0001), with bits[12:1] as follows
MODE
MOD2
MOD1
ST[3:1]
WT[2:1]
CP[4:1]
Undefined
0
0
XXX
XX
XXXX
Normal
0
1
XXX
XX
CP[4:1]
Polling
1
0
ST[3:1]
XX
CP[4:1]
Polling + INT Timer
1
1
ST[3:1]
WT[2:1]
CP[4:1]
ST[3:1] — OFF Time between Samples (tWAIT)
During both Polling modes (with and without INT Timer ’Wake–Up’, MOD2=[1]), these bits select the interval of time (tWAIT) that
the Input Blocks are turned OFF; switch transitions are not detected during the OFF interval.
Sample OFF Time Prescales
ST[3:1]
Multiplier
Selected
OFF Time, tWAIT (ms)
[tDETECT (4.8ms typ.) * Multiplier]
ON Time (ms)
000
5
15 – 25
5.1 – 6.3
001
9
30 – 55
5.1 – 6.3
010
17
60 – 90
5.1 – 6.3
011
25
100 – 140
5.1 – 6.3
100
33
145 – 185
5.1 – 6.3
101
41
195 – 215
5.1 – 6.3
110
49
220 – 245
5.1 – 6.3
111
57
250 – 320
5.1 – 6.3
MOTOROLA TSG IC DEVICE DATA
13
MC33884
DESCRIPTION (Continued)
WT[2:1] — Wake–Up Time
These bits let the device assert an external interrupt (INTB) at the following intervals during Polling mode (MOD2=MOD1=1).
Wake–Up Delay Prescales
WT[2:1]
Multiplier
Selected
Wake–Up Interrupt, tWAKE (ms)
[tDETECT (2.8ms typ.) * Multiplier]
00
512+1
2400 – 3200
01
256+1
1200 – 1600
10
128+1
600 – 750
11
64+1
290 – 360
CP[4:1] — Configure Programmable Switch
Configure the programmable inputs SP[4:1] to detect either an external switch–to–ground (internal current source) or an external
switch–to–battery (internal current sink). Note that this configuration may be entered in any of the three valid Operating Modes
(see MOD[2:1]) within the Run command.
Programmable Switch Bit Definition
CPx
External Switch to:
0
Ground
1
Battery
Tri–State Command
This command places an external switch into a “Tri–State” condition, essentially disconnecting the wetting current (if the switch
is metallic) and the sustain current. The internal input–threshold comparator is still internally connected to its external pin. This
command does not change the mode of operation (e.g., a Tri–State command received while in Polling mode leaves the part in
that mode). Note that the Tri–State register clears all bits to [0] (all inputs in Tri–State) in response to a hardware reset; all inputs
also remain in Tri–State after exiting the Sleep mode.
MSB
Bit
Command
Tri–State
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
TG6
TG5
TG4
TG3
TG2
TG1
TP4
TP3
TP2
TP1
TB2
TB1
—
—
—
—
0
0
0
0
0
0
0
0
0
0
0
0
RESET VALUES:
Tri–State Register
TG[6:1] — Tri–State Switch–to–Ground
TB[2:1] — Tri–State Switch–to–Battery
TP[4:1] — Tri–State Programmable Switch
Tri–State Bit Definition
14
TGx, TBx, TPx
Input Configured to:
0
Input Disabled [DEFAULT]
1
Input Enabled
MOTOROLA TSG IC DEVICE DATA
MC33884
DESCRIPTION (Continued)
Metallic Command
This command enables the pulsed wetting current for an external metallic switch and disables it for an external non–metallic
switch. This command does not change the mode of operation (e.g., a Metallic command received while in Polling mode leaves
the part in that mode). Note that the Run register values are unknown after exiting the Sleep mode.
MSB
Bit
Command
Metallic
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1
0
1
MG6
MG5
MG4
MG3
MG2
MG1
MP4
MP3
MP2
MP1
MB2
MB1
—
—
—
—
U
U
U
U
U
U
U
U
U
U
U
U
RESET VALUES:
Metallic Register
U: Unknown value coming out of Sleep mode; must configure with Metallic command.
MG[6:1] — Metallic Switch–to–Ground
MB[2:1] — Metallic Switch–to–Battery
MP[4:1] — Metallic Programmable Switch
Metallic Switch Bit Definition
MGx, MBx, MPx
Accepted Switch Type:
0
Non–metallic
1
Metallic (enable wetting current pulse)
Test Mode
Bit 16 is reserved for placing the device into a special IC Test mode. It is used to confirm various internal functions.
MSB
Bit
Command
IC Test Mode
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
MOTOROLA TSG IC DEVICE DATA
15
MC33884
DESCRIPTION (Continued)
SPI Responses
Response Protocol (Data out of SO)
Table 1: SPI Response Protocol
MSB
Bit
Mode
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Reset/Sleep
0
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Normal
0
1
MASL
INT
SG6
SG5
SG4
SG3
SG2
SG1
SP4
SP3
SP2
SP1
SB2
SB1
Polling
1
0
MASL
X
SG6
SG5
SG4
SG3
SG2
SG1
SP4
SP3
SP2
SP1
SB2
SB1
Polling + INT Timer
1
1
MASL
INT
SG6
SG5
SG4
SG3
SG2
SG1
SP4
SP3
SP2
SP1
SB2
SB1
LABEL DEFINITIONS
SG[6:1]
Switch–to–Ground Flag
MASL
Master/Slave Identification Flag
SB[2:1]
Switch–to–Battery Flag
INT
External Interrupt Flag
SP[4:1]
Programmable Switch Flag
Reset/Sleep
When the Reset (RSTB) input is active (logic [0]), all internal registers are cleared, thereby placing the device in Sleep mode
and upon the RSTB input returning to the inactive state (logic [1]) the MC33884 remains in Sleep mode. A SPI command, received
from the microprocessor, is necessary to command the device out of Sleep mode.
MSB
Bit
Mode
Reset/Sleep
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Note: The SPI response given while sending the command to exit Sleep mode should be ignored due to unknown power–up state.
16
MOTOROLA TSG IC DEVICE DATA
MC33884
DESCRIPTION (Continued)
Normal and Periodic
Bits [16:15] identify one of the three operating modes: Normal, Polling, and Polling + INT Timer. The remaining bits identify the
device as the Master or a Slave, whether the device has an interrupt that has not been cleared, and the state of all the inputs.
MSB
Bit
Mode
LSB
Bit
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Normal
0
1
MASL
INT
SG6
SG5
SG4
SG3
SG2
SG1
SP4
SP3
SP2
SP1
SB2
SB1
Polling
1
0
X
Polling + INT Timer
1
1
INT
MASL — Master/Slave Identification Flag
This flag is the same as the state of the MASL pin. It provides software identification of the configuration of each IC.
MASL Bit Definition
MASL
Device is a
0
Slave
1
Master
INT — External Interrupt Flag
This flag identifies this particular IC as the initiator of an external interrupt. It is the inverse of INTB.
INT Bit Definition
Bit 16
15
14
13
Type of Interrupt
Normal
Mode
0
1
X
0
Nothing has happened
1
Switch Interrupt
Polling
1
0
X
X
–
Polling + INT
Ti
Timer
1
1
X
0
Nothing has happened
1
Wake–Up Interrupt
SG[6:1] — Switch–to–Ground Flag
SB[2:1] — Switch–to–Battery Flag
SP[4:1] — Programmable Switch Flag
These twelve flags indicate the state of all switch inputs:
Switch State Bit Definition
SGx, SBx, SPx
External Switch is:
Mode
Input States Latched:
0
Open
Normal
At the moment CSB transitions to logic 0.
1
Closed
Polling
Tri–State
All Tri–State inputs have their wetting and sustain currents disabled. By definition, all disabled inputs return the following value
for the switch state whenever SPI data is exchanged:
Tri–State Bit Definition
MOTOROLA TSG IC DEVICE DATA
SGx, SBx, SPx
External Switch is:
0
Tri–State
17
MC33884
PACKAGE DIMENSIONS
–A–
24
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN
EXCESS OF D DIMENSION AT MAXIMUM
MATERIAL CONDITION.
13
–B–
12X
P
0.010 (0.25)
1
M
B
M
12
24X
D
J
0.010 (0.25)
M
T A
S
B
S
F
R
C
–T–
SEATING
PLANE
M
22X
G
K
X 45 _
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
15.25
15.54
7.40
7.60
2.35
2.65
0.35
0.49
0.41
0.90
1.27 BSC
0.23
0.32
0.13
0.29
0_
8_
10.05
10.55
0.25
0.75
INCHES
MIN
MAX
0.601
0.612
0.292
0.299
0.093
0.104
0.014
0.019
0.016
0.035
0.050 BSC
0.009
0.013
0.005
0.011
0_
8_
0.395
0.415
0.010
0.029
CASE 751E–04
ISSUE E
18
MOTOROLA TSG IC DEVICE DATA
MC33884
NOTES
MOTOROLA TSG IC DEVICE DATA
19
MC33884
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respective owners.
Motorola, Inc. 2001.
E
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20
MOTOROLA TSG IC DEVICE DATA
◊
MC33884/D
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www.datasheetcatalog.com
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