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Datasheet: MLX90711 (Melexis, Inc.)

Position/movement Sensing Auto-shutoff

 

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MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 1 of 15
Data Sheet
Rev. 003
Dec/02
Features and Benefits
!"
Safety Auto shut off based on movement or position sensing.
!"
Low cost minimal external components.
!"
Very reliable patented capacitive sensor,
insensitive to erosion and dust.
!"
On chip calibrated timer.
!"
Drives different relay types, including low cost
12V relays and most custom made relays.
!"
Auto shut off status is indicated via a led.
!"
Several timing options available.
Applications
!"
Irons, fryers, ...


Ordering Information
Part No.
Temperature Suffix
Package Code
Option Code*
MLX90711
C ( 0C to 70C )
AA (PDIP8)
BB / BC
MLX90711
C ( 0C to 70C )
DC (SOIC8)
BB / BC
* See Option Code Table for details
1. Functional Diagram
Regulator & bias
Sequencer
Osc
Relay
Logic
ADC
LED
VSS
VDD1
RD
LEDP
SUM
CA1
CA0






2. Description
The Automatic Shut-Off is a safety system, which
turns off the electrical power of a load based either
on movement detection or position detection. This
detection will be taken into account after a well-
defined time delay. A typical application is the
safety feature in irons, which will switch off the
heating element when the iron is left immobile for a
well defined period, which can be dependant on
the position. The state of the Auto Shut-Off can be
indicated with a led.
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711 Page
2 of 15 Data Sheet
Rev. 003
Dec/02
TABLE OF CONTENTS
FEATURES AND BENEFITS........................................................................................................................1
APPLICATIONS ............................................................................................................................................1
ORDERING INFORMATION .........................................................................................................................1
1.
FUNCTIONAL DIAGRAM ...................................................................................................................
...1
2.
DESCRIPTION ....................................................................................................................................
...1
3.
ABSOLUTE MAXIMUM RATINGS........................................................................................................3
4.
MLX90711 ELECTRICAL SPECIFICATIONS.......................................................................................3
5.
MLX90711 SPECIFIC SPECIFICATIONS .............................................................................................3
6.
GENERAL DESCRIPTION ....................................................................................................................5
7.
PINOUT DESCRIPTION ........................................................................................................................8
8.
APPLICATIONS INFORMATION ..........................................................................................................9
8.1.
A
PPLICATION EXAMPLE
.................................................................................................................................. 9
8.2.
S
ENSOR
O
UTPUT
M
EASUREMENT
................................................................................................................. 10
8.3.
O
PTION
C
ODE
T
ABLE
................................................................................................................................... 11
9.
RELIABILITY INFORMATION.............................................................................................................12
10.
ESD PRECAUTIONS ...........................................................................................................................12
11.
PACKAGE INFORMATION .................................................................................................................13
12.
DISCLAIMER .......................................................................................................................................15
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 3 of 15
Data Sheet
Rev. 003
Dec/02
3. Absolute Maximum Ratings
Supply Voltage, V
DD1
(overvoltage)
73V
Supply Voltage, V
DD1
(operating)
68V
Maximum chip temperature
125
C
ESD Sensitivity (AEC Q100 002)
2kV

Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute
maximum-rated conditions for extended periods may affect device reliability.

4. MLX90711 Electrical Specifications
DC Operating Parameters T
A
= 0
o
C to 85
o
C
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Power supply range
VDD1
I
VDD1
= 5 mA
67
68
73
V
Current consumption
Idd1
VDD1 = 50V
0.1
0.6
3.1
mA

5. MLX90711 Specific Specifications
Internal clock
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Clock
period
Tcl
48.9
usec
Initial deviation
Erri
-8
8
%
Deviation over temperature
Errt
-4
4
%
Deviation over Vdd1
Errv
-3
3
%
Auto shut-off timing tolerance
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
DO auto shut-off time
td
-15
15
%
HOR auto shut-off time
th
-15
15
%
VERT auto shut-off time
tv
-15
15
%
Driver Resistance
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Relay Driver On resistance
Rrdon
At 30mA
90
ohm
Led Driver On resistance
Rledon
At 30mA
50
ohm
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 4 of 15
Data Sheet
Rev. 003
Dec/02
Sensor Outputs
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Leakage current at CA0
Ica0lk
V
in
= 0V, V
in
= 4.2V
-1
1
uA
Leakage current at CA1
Ica1lk
V
in
= 0V, V
in
= 4.2V
-1
1
uA
Power on reset
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Upper
level
PORHI
31 42 V
hysteresis PORHYS
4
13
V
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 5 of 15
Data Sheet
Rev. 003
Dec/02
6. General Description
Introduction
The Automatic Shut-Off is a safety system which
turns off the electrical power of a load based either
on movement detection or position detection. This
detection will be taken into account after a well-
defined time delay. A typical application is the
safety feature in irons, which will switch off the
heating element:
if the iron is connected to the mains and left
immobile in the ironing position for a time larger
than TH;
or
if the iron is connected to the mains and left
vertically up on heel rest for a time larger than TV.
or
if the iron is connected to the mains and left
vertically down on heel rest for a time larger than
TD.
The heating of the iron is turned on again
immediately after detecting a different position (or
detecting a movement).
Sensing Principal
Melexis developed a new concept of Auto Shut-Off
in which the position or movement detection is
realized with a patented capacitive detection. This
sensor uses the movement of a ball, but the
detection is capacitive, and therefore, the system
does not need a conductive contact. Consequently,
the system is insensitive to erosion and dust.
The sensitivity of the asic is very high, and a ball
with a diameter as small as 3 mm can be used.

This detection system described in the following
section is protected by a patent (Patent European
application Nr. EP0589092; US application Nr.
US5627316).
Detection system
The detection is done based on the ratio of two
variable capacitors. These capacitors can be the
parasitic capacitances of a small conductive ball
placed on a cavity in the pcb. As the pcb is rotated
in its lengthy direction, the ball is running forwards
and backwards on the pcb. Copper tracks placed
on the PCB at the edges of the hole will be used as
the terminals of capacitors. We can define two
capacitors made up of 2 copper tracks with a
(conductive) ball in between. If the ball rolls just
between 2 copper tracks, the distance between the
copper tracks and the ball will decrease, thus
increasing their capacitance. The circuitry on chip
performs a measurement of the difference
between these 2 caps. It controls the sense
terminals (CA0, CA1, SUM), processes their data
and drives 2 outputs: RD (to drive a relay) and
LEDP (to drive an LED). The information from the
detection system results in a momentary down,
up or horizontal position. This information can be
used to generate position detection or can be
interpreted as movement detection.

When used as a position sensor, the output of the
sensor consists of 3 digital signals, indicating the
position of the sensor: the ball is in the middle
(horizontal), is at the front side (down) or is at the
end (up). The position of the ball is sensed every
15.6 msec. For this the analog output voltage of
the sensor circuit is sent to 3 comparators with
hysteresis. If the result is equal for 3 consecutive
samples, the corresponding digital signal
(DOWN, UP or HOR) becomes valid. This signal
is used to evaluate the Auto Shut-Off function.
The Auto Shut-Off is active only when UP
remains high during a time period larger than TV
or when HOR remains high during a time period
larger than TH or when DOWN remains high
during a time larger than TD. The signals UP,
HOR and DOWN are debounced.
When the Auto Shut-Off is active the relay driver
is activated. Using a NC (normally closed) type
relay, this can switch off the power of the heating
element.
When the module is moved, the ball can roll
forwards and backwards in such a way that the
states UP, HOR and DOWN never remain stable
for a time more than TV, TH and TD respectively
and the relay output is not activated.
As long as the vertical inclination is enough to
keep the ball in the "vertical" area, the state UP
remains active.

When used as a movement sensor the output of
the sensor has only one signal, which indicates
that the position of the ball has changed. If this
signal is inactive for the predefined time period,
called TASO, the chip enters the Auto Shut-Off
State. The position of the ball is sensed every
15.6 msec. When the Auto Shut-Off is active the
relay driver is activated. Using a NC type relay,
this can switch off the power of the heating
element.
When the module is moved, the ball can roll
forwards and backwards and due to this the chip
continuously detects a change of state of the
sensor.

MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 6 of 15
Data Sheet
Rev. 003
Dec/02
PCB
Regulator & bias
Sequencer
Osc
Relay
Logic
ADC
LED
VSS
VDD1
RD
LEDP
SUM
CA1
CA0
MLX90711
down
horizontal
up
copper track
cavity
ball
ball position
Position/Movement detection system
Power On Reset
In the chip there is a block "Power On Reset"
(POR), which tracks the level of the power supply
voltage Vdd1 and defines the state of the chip.
If Vdd1 is less than the high POR level (PORHI)
after initial plugging into the mains, the chip is in
the "reset state". When Vdd1 becomes higher
than the PORHI level, the operation of the chip
starts: start up sequence, heating up and then the
chip enters in "normal operation mode".
If Vdd1 becomes less than the low POR level
(PORLO), (PORLO=PORHI-HYS), for more than
7.8msec the chip enters the "reset state".
Power down timing
After disconnecting the mains , the chip will reset:
- within typical 0.25sec when the coil is not
activated (iron is heating)
- within typical 2.5sec when the coil is activated
(iron is in ASO)
Relay and led driver options
The relay is driven by a pulsed signal instead of a
continuous signal. Consequently, the power
consumption is reduced.
The relay driver performs this feature. There are
four duty cycles available: 14.4%, 16%, 28% and
31%. During 7.8 ms after the switching time, the
duty cycle is increased. This will give an
increased energy to the relay for a short time at
the moment the relay coil must change the state
of the contact. The switching time starts by
applying the control voltage on the coil of the
relay.
The values of the duty cycles for the first 7.8 ms
are in the table in brackets. The switching
frequency of relay and led are the same and are
typically 20.48KHz.
SRD1 SRD2
Relay DC
Led DC
0 0 14.4%(28%) 14.4%(28%)
0 1 28%(43%) 28%(43%)
1 0 16%(31%) 16%(31%)
1 1 31%(48%) 31%(48%)
VSS
LEDP
VDD1
MLX90711
RD
Relay - Led output configuration
The type of relay should be normally closed (NC).
A NC relay is opened by applying the control
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 7 of 15
Data Sheet
Rev. 003
Dec/02
voltage on its coil and in this case the module is
in Auto Shut-Off mode.
Movement Auto Shut-Off time
When used as a movement Auto Shut-Off
module, several timing options are available. All
timings are derived from the on chip oscillator
and have thus the same tolerance.
If the module is left immobile for a time longer
than TASO the auto shut-off function becomes
active. There is also an additional time period
TADI. This time is valid only in the vertical state
and determines the time between shut-off and the
start of the led blinking.
Movement sensor options
version TASO
TADI
V1 30
sec
0
V2
30 sec
4 min
V3 4
min 0
V4 1
min 0
V5 10
min
0
V6 2
min 0
V7 8
min 0
V8
30 sec
8 min
Position Auto Shut-Off
When used as a position Auto Shut-Off module,
several timing options are available. All timings
are derived from the on chip oscillator and have
thus the same tolerance.
Three different time delays can be defined: the
horizontal shut-off (TH), the vertical shut-off (TV)
and the down shut-off (TD).
Position sensor options
version TD
TH
TV
V1 30" 30" 4'
V2 30" 30" infinity
V3 30" 5" 8'
V4 30" 30" 8'
Start up sequence
When connecting the asic to the AC line the asic
first passes through a startup sequence. The
duration of this sequence is 1.25 or 3.75 seconds
depending on the duration of phase 1. After the
start up test the normal function of the chip
begins. This sequence involves the following
phases:
PHASE 0: The duration is a time period
"TS", which incorporates the Power On Reset
time period. This time `TS" is typically 0.2 sec.
PHASE 1: The duration is 0.5 second or 3
seconds. This can be defined by the mask option
SPH1. During this phase the iron heats. The ASO
function is not active. The LED is off. The relay is
NC and the control voltage is not applied to its
coil during this phase.
PHASE 2: The duration is 0.75 second*.
The ASO function is active. The iron is not
heating. The control voltage is applied to the coil
of the relay during this phase. The LED indicates
that the ASO function is active. Some additional
information is sent out by the led driver during
this phase. This information involves three
frequency codes.
- The first code is the highest digital clock
(20.48kHz). The duration is 250ms.
- The second code is the information of the
position sensor. The frequency depends on the
position of the module. See table below.
- The third code is the information for the
metal mask where the customer specific options
are defined. It is coded using one of five
frequencies (20kHz, 10kHz, 5kHz, 2.5kHz,
1.25kHz).
*Phase2 is 0.5s for MLX90711 BC. No third code.
Position
LED frequency (KHz)
UP 1.28
Between UP and HOR
2.56
HOR 5.12
Between HOR and DO
10.24
DO 20.48
EMC
Thanks to a special algorithm the sensor is made
very insensitive to noise and AC line coupling.
Side Position Shut-Off
The design of the cavity in the pcb, on which the
ball of the sensor is moving, as well as the design
of the protective cover important aspects.
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 8 of 15
Data Sheet
Rev. 003
Dec/02
PCB top view
normal rotation axis
side position
rotation axis

When designed properly the function of the Auto
Shut-Off module can also be defined when the
module is rotated around the axis perpendicular
to the normal axis, even when the ball tends to
fall off of the pcb. In the application of an iron this
can be useful for defining the functionality when
the iron is put at his side.
Heating Up feature
If the heating up feature is present, it inhibits the
Auto Shut-Off function for 1 minute and 30
seconds after the start up sequence regardless of
the position or the movement of the iron. If the
iron is left immobile the asic will activate the relay
output after 1 min and 30 sec added to the time
TH (or TV or TD depending on the position).
If the heating up feature not present, the Auto
Shut-Off function is available as soon as the iron
is plugged: so the relay contacts will switch off
after a time TH if it is left in the ironing position
without movement, or after time TV if it is left
vertically up, or after time TD if it is left vertically
down.
Sensor test mode
To measure the performance of the sensor in the
module, a sensor test mode is implemented. This
test mode is activated via the test pin TEST1,
which is normally left open. When connecting the
pin TEST1 to an external 12V supply (with
respect to the asic ground VSS) via a resistor of
220 Kohm the test mode is activated and the
output of the on chip integrator is now available at
the pin TEST1. Depending on the position of the
sensor the voltage at the TEST1 output will
change.
The pin TEST1 is also used as digital I/O during
the asic production tests.
Options
Following is a summary of the options that can be
changed with the metal mask:
parameter value
option
POSMOV 0 Position
sensing
1
Movement
sensing
V1--V8
Select timing options
SPH1 0
Phase 1 of startup
sequence is 0.5 sec.
1
Phase 1 of startup
sequence is 3 sec.
HEATUPM
0
No heatup feature
1
Heatup feature present
SRD1 + SRD2
Select relay and led driver options
7. Pinout Description
PDIP8 SOIC8 Name
Type
Description
1
6
CA1
Output
Sensor output CA1
2 7 VSS
Supply Ground
3 8 SUM
Input
Sensor
input
4 1 TEST1 Output Test
output
5 2 VDD1 Supply Power
supply
6 3 LEDP
Output Led
driver
7 4 RD
Output Relay
driver
8
5
CA0
Output
Sensor output CA0
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 9 of 15
Data Sheet
Rev. 003
Dec/02
8. Applications Information
8.1. Application example
Application Example
PCB
VSS
VDD1
RD
LEDP
SUM
CA1
CA0
MLX90711
L
Load
N
R1
D1
LED1
D2
C1
REL1

The above drawing shows the electrical
schematic of a typical application with NC relay
type.
The asic is directly connected to the AC line via a
resistor R1 and diode D1, thus supplying the asic
during only the positive cycle of the AC line
voltage. A capacitor C1 is therefore added
between VDD1 and VSS to smooth the asic
supply voltage. The voltage at VDD1 is limited to
approximately 60V. A 12V relay REL1 can be
used to load the pin RD. The relay is driven with
a well-defined duty cycle to ensure that the relay
is driven with the right energy. The relay driver
needs a flyback diode D2. A led LED1 can be
added to indicate the state of the asic. If no led is
used, it must be replaced by a short circuit.
Special care must be paid to the layout of the
sensor on the pcb and to the connections
between sensor and asic. The asic is designed to
detect very small variations in capacitance in the
sensor. Therefore parasitic capacitances must be
kept as small as possible, and injection of noise
must be avoided.










MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 10 of 15
Data Sheet
Rev. 003
Dec/02
8.2. Sensor Output Measurement
sensor output measurement
PCB
VSS
VDD1
RD
LEDP
SUM
CA1
CA0
90711
L
Load
N
TEST1
220Kohm
12 V
signal at TEST1 output
detecting UP state
signal at TEST1 output
detecting DOWN state
MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 11 of 15
Data Sheet
Rev. 003
Dec/02
8.3. Option Code Table
The table below lists all option values for the available option codes.
OPTION BB
BC
Relay Type
NC (Normally Closed)
NO (Normally Opened)
POSMOV
0
Position sensing
1
Movement sensing
V1--V8 V4
td=30 s, th=30 s, tv=8min

TASO = 11 min
SPH1 1
Startup Phase1 = 3 s
0
Startup Phase1 = 0.5 s
HEATUPM 1
Heatup present
0
No heatup
SRD1+ SRD2 00
14.4% (double 28%) relay
& led driver duty cycle
00
14.4% (double 28%) relay
& led driver duty cycle

































MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 12 of 15
Data Sheet
Rev. 003
Dec/02
9. Reliability
Information
Melexis devices are classified and qualified regarding suitability for infrared, vapor phase and wave
soldering with usual (63/37 SnPb-) solder (melting point at 183degC).
The following test methods are applied:

IPC/JEDEC J-STD-020A (issue April 1999)
Moisture/Reflow Sensitivity Classification For Nonhermetic Solid State Surface Mount Devices
CECC00802 (issue 1994)
Standard Method For The Specification of Surface Mounting Components (SMDs) of Assessed Quality
MIL 883 Method 2003 / JEDEC-STD-22 Test Method B102
Solderability

For all soldering technologies deviating from above mentioned standard conditions (regarding peak
temperature, temperature gradient, temperature profile etc) additional classification and qualification tests
have to be agreed upon with Melexis.

The application of Wave Soldering for SMD's is allowed only after consulting Melexis regarding assurance
of adhesive strength between device and board

For more information on manufacturability/solderability see quality page at our website:
http://www.melexis.com/
10. ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.



























MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 13 of 15
Data Sheet
Rev. 003
Dec/02
11. Package Information
AA (PDIP8) Package Dimensions
9.02
10.16
Min
Max
18.67
19.68
18.67
19.68
22.35
23.67
24.89
26.92
31.24
32.51
0.20
0.38
2.54
BSC
1.1
5
1.7
7
0.35
0.55
0.39
Min
Dimension
8 Leads
16 Leads
18 Leads
20 Leads
14 Leads
24 Leads
A
6.10
7.11
5.33
MAX
2.93
4.06
7.62
BSC
10.92
Max
A
Notes:
1-All measurements in mm
2-Body dimensions do not include mold
flash or
protrusion - not to exceed
0.15mm






















MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 14 of 15
Data Sheet
Rev. 003
Dec/02
DC (SOIC8) Package Dimensions
0.40
1.27
0
o
to 8
o
2.35
2.65
0.010 min.
0.33
0.51
A
Dimension
8 Leads
14 Leads
A
4.80
5.00
Min
Max
8.55
8.75
16 Leads
9.80
10.00
3.80
4.00
5.80
6.20
1.27
Notes:
1-All nominal measurements in millimeters
2-Body dimensions do not include mold flash or
protrusion - not to exceed 0.15mm

























MLX90711
Position/movement Sensing Auto-Shutoff
3901090711
Page 15 of 15
Data Sheet
Rev. 003
Dec/02
12. Disclaimer

Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in
its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the
information set forth herein or regarding the freedom of the described devices from patent infringement.
Melexis reserves the right to change specifications and prices at any time and without notice. Therefore,
prior to designing this product into a system, it is necessary to check with Melexis for current information.
This product is intended for use in normal commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or high reliability applications, such as military,
medical life-support or life-sustaining equipment are specifically not recommended without additional
processing by Melexis for each application.
The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not
be liable to recipient or any third party for any damages, including but not limited to personal injury,
property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or
consequential damages, of any kind, in connection with or arising out of the furnishing, performance or
use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow
out of Melexis' rendering of technical or other services.
2002 Melexis NV. All rights reserved.



For the latest version of this document,
go to our website at:
www.melexis.com
Or for additional information contact Melexis Direct:
Europe and Japan:
All other locations:
Phone: +32 13 67 04 95
Phone: +1 603 223 2362
E-mail: sales_europe@melexis.com
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