MLX90215 Datasheet DownloadLink 4758

MLX90215
Precision Programmable
Linear Hall Effect Sensor
Features and Benefits
•
•
•
•
•
•
•
Programmable Linear Hall IC
Quad Switched / Chopper Stabilized
Ratiometric Output for A/D Interface
Adjustable Quiescent Voltage (VOQ )
Very Low Quiescent Voltage Temperature Drift
Adjustable Sensitivity
Adjustable Temperature Compensation of Sensitivity
Applications
•
•
•
Linear Position Sensing
Rotary Position Sensing
Current Sensing
Ordering Information
Part No.
MLX90215
MLX90215
Temperature Suffix
L (-40oC to 150oC)
E (-40oC to 85oC)
Functional Diagram
Description
VDD
2
OTPROM (ROM)
1
Shift Register (RAM)
DAC
DAC
DAC
Program
Decoder
Hall Plate
Chopper
3
Package
VA(4 Lead SIP)
VA(4 Lead SIP)
4
Pin 1 - VDD (Supply)
Pin 2 - Test/Readback Enable
Pin 3 - VSS (Ground)
Pin 4 - Output
The MLX90215 is a Programmable Linear Hall Effect
sensor IC fabricated utilizing silicon-CMOS technology.
It possesses active error correction circuitry which
virtually eliminates the offset errors normally associated
with analog Hall Effect devices. All magnetic response
functions of the MLX90215 are fully programmable for
even greater versatility. The VOQ (VOUT@ B=0),
sensitivity, direction of slope and the magnitude of
sensitivity drift over temperature, are all programmable.
The ratiometric output voltage is proportional to the
supply voltage. When using the supply voltage as a
reference for an A/D converter, fluctuations of ±10% in
supply voltage will not affect accuracy. When
programmed for a conventional sensitivity (with a
positive gain), the voltage at the output will increase as
a South magnetic field is applied to the branded face of
the MLX90215. Conversely, the voltage output will
decrease in the presence of a North magnetic field. The
MLX90215 has a sensitivity drift of less than +1%
error, and VOQ stability drift of less than +0.4% error,
over a broad temperature range.
Note: Static sensitive device, please observe ESD precautions.
3901090215
Rev 007
Page 1
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
MLX90215 Electrical Specifications
DC Operating Parameters TA = -40oC to 150oC, VDD = 5.0V (Unless otherwise specified)
Parameter
Min
Typ
Max
Units
Supply Voltage
Symbol Test Conditions
VDD
Operating
4.5
5.0
5.5
V
Supply Current
IDD
B = 0, VDD = 5V, IOUT = 0
2.5
4.0
6.5
mA
Output Current (1)
IOUT
VDD = 5V + 10%
-2
-
2
mA
Quiescent Output Voltage (2)
VOQ
10-Bit Programmable, B = 0
0.5
-
4.5
V
Output Voltage (1)
VOH
VDD = 5V, IOUT = -2mA
4.50
4.65
Output Voltage (1)
VOL
VDD = 5V, IOUT = 2mA
Sampling Rate
fSAMP
RoughGain @ Max and Min
Bandwidth (3)
BW
RoughGain @ Min
Bandwidth (3)
BW
RoughGain @ Max
0.130
-
kHz
Step Response Time (6)
TRMIN
RoughGain @ Min
25
-
µs
Step Response Time (6)
TRMIN
RoughGain @ Max
250
Offset Voltage Adjustment
Resolution
Offset Voltage Drift
over Temperature
Offset Voltage Drift (2)
over Temperature
Range of Sensitivity (7)
∆VOQ
B = 0, TA = 25oC , 1/2 Vdd = 1
B = 0, TA = 25oC , 1/2 Vdd = 0
o
o
∆VOQ/∆T B = 0, TA = -40 C to 150 C
S < 100mV/mT & VOQ > 0.75V
o
o
∆VOQ/∆T B = 0, TA = -40 C to 150 C
S > 100mV/mT & VOQ < 0.75V
s
13-Bit Programmable
-1.5
-6.0
-20
-
Peak to Peak Noise (4)
Output Resistance
Sensitivity Drift(5)
4
V
0.35
0.50
V
-
40
kHz
-
1.300
kHz
µs
-
1.5
6.0
20
mV
mV
mV
-40
-
40
mV
5
-
140
mV/mT
8
25
60
mV
ROUT
Ω
6
o
TA = 25 C
-1
-
1
%
Notes:
(1) If output current and voltage specifications are exceeded, linearity will be degraded.
(2) If VOQ is programmed beyond these limits, the temperature compensation may become a problem at high
temperatures. It is not recommended to program values of VOQ below 1V or above 4V when sensitivity exceeds 100
mV/mT. Temperature instability can occur on some devices under these conditions.
(3) Bandwidth is related to the sample rate and ROUGHGAIN. Bandwidth is estimated by (sample rate / 30)
(4) Peak to Peak Noise is a function of ROUGHGAIN setting. See page 5, Peak to Peak Noise versus Sensitivity.
(5) Sensitivity drift is independent of other parameters and does not include individual tolerances (∆VOQ or ∆VOQ/∆T).
The tolerance for sensitivity ±1% of its initial value. This does not include tolerance stack-up.
(6) If the step input occurs in the middle of a sample interval, the small signal response delay will double. For
ROUGHGAIN values less than or equal to 3, response time may be limited by the slew rate.
(7) 1 mT = 10 Gauss
Melexis Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function, or design. Melexis does not
assume any liability arising from the use of any product or application of any product or circuit described herein.
3901090215
Rev 007
Page 2
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
How does it Work?
The MLX90215 programming is done through the
output pin, by changing supply voltage levels. Please
note that the VDD is raised to approximately 13V and
18V during programming. Any connected components
must also tolerate this voltage excursion. When the
supply voltage is at 4.5V to 5.5V, the output behaves
normally. If the supply voltage is raised to 13V, the
output then behaves as an input, or LOAD mode,
allowing the 37-bit word to be clocked in. All data is
loaded through a single line, with no dedicated clock
signal. Clock and data are integrated into one signal
which is initiated with the beginning of the LOAD
sequence, then clocked with the positive edge of each
bit. Variables are changed with the PC software and
loaded into the temporary register of the device (RAM)
via the timings of the programmer’s microcontroller.
Data can be loaded as many times as desired while in
LOAD mode. Once a word is loaded, results are
checked by observing the output voltage. This can be
done with an external Voltmeter attached directly to pin
4 of the device, or with the internal ADC of the
programmer. Once the desired program is loaded, the
word can be “Zapped” permanently into ROM.
This is done when the supply voltage rises above 18V,
or ZAP mode, creating enough current to “Zap” 31
zener diodes which correspond to the temporary
register. The ZAP function is a one-time function and
cannot be erased.
The above description is only for reference. The voltage
levels and data transfer rates are completely controlled
by the ASIC programmer. For more information on the
programmer hardware, contact Melexis and request a
datasheet for the SDAP programmer.
ranges. With the HALFVDD function disabled, the VOQ
can be programmed within a range of 10% to 90% VDD
with about 5mV per step resolution. With the
HALFVDD function enabled, the device may be
programmed within a 2V to 3V window with less than
1mV per step resolution
Programming the Sensitivity (Gain)
The sensitivity is programmed with a ROUGHGAIN
and a FINEGAIN adjustment. The ROUGHGAIN is
adjusted by utilizing three bits, or 8 increments. The
FINEGAIN is programmed with 10 bits or 1024
increments. The sensitivity can be programmed within a
range of 5mV/mT to 140mV/mT. Another 1-bit function
allows the direction of the sensitivity to be reversed.
The INVERTSLOPE function, when activated, will
cause the Voltage output of the MLX90215 to decrease
in the presence of a South magnetic field, and to
increase in the presence of a North magnetic field. Table
2 expresses examples of sensitivity resulting from
programming ROUGH GAIN and FINE GAIN codes,
with the INVERT SLOPE function turned off.
Note: Tables 1 and 2 are examples how various codes affect the device.
Output voltage will vary slightly from device to device. Use these tables
for reference only.
Table 2 - Programming Sensitivity
RoughGain
FineGain
Output
Units
0
0
4.1
mV/mT
0
1023
9.4
mV/mT
1
0
6.2
mV/mT
1
1023
14.6
mV/mT
2
0
9.5
mV/mT
2
1023
22.4
mV/mT
3
0
14.2
mV/mT
3
1023
33.1
mV/mT
Table 1 - Programming Offset Voltage (V OQ)
4
0
21.5
mV/mT
HalfVDD
OffsetDAC
Output
Units
4
1023
50.4
mV/mT
0
0
4.97
V
5
0
31.3
mV/mT
0
512
2.47
V
5
1023
72.5
mV/mT
0
1023
0.03
V
6
0
46.2
mV/mT
1
0
3.07
V
6
1023
107
mV/mT
1
512
2.45
V
7
0
68.9
mV/mT
1
1023
1.83
V
7
1023
140
mV/mT
Programming The Quiescent Offset Voltage (VOQ)10
bits, 1024 steps of resolution, are allotted to adjust the
Quiescent Offset Voltage (VOQ). By utilizing the
HALFVDD function, the VOQ can be set to one of two
3901090215
Rev 007
Page 3
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
Temperature Compensation
Temperature compensation (TC) is defined as the
change in sensitivity over temperature. Expressed in
(Parts Per Million per Degree Celcius) ppm/oC.
TC =
Sens T 1 − Sens T 2
1
ppm
∗
∗ 10 6 o
Sens 25
T1 − T 2
C
SensT1 = Sensitivity measured at Temperature 1 (T1)
SensT2 = Sensitivity measured at Temperature 2 (T2)
Sens25 = Initial Sensitivity measured at 25oC
Programming the Temperature Compensation
The MLX90215 has a 5-bit (32 step) programmable
adjustment that changes it’s sensitivity drift over a given
temperature range. By adjusting the TC code the
sensitivity can be programmed to increase as
temperature increases to counteract the decrease in
magnetic flux most magnets display over temperature.
For example a SmCo (Samarium Cobalt) magnet has a
temperature coefficient of approximately -300 ppm/oC.
The MLX90215 can be programmed with a TC of 300
ppm/oC to counteract the TC of the magnet and greatly
improve linearity in the application over temperature.
Table 3 - Temperature Compensation
TC Code
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
3901090215
Rev 007
Min
-700
-625
-525
-450
-350
-275
-200
-100
125
225
300
375
450
525
600
675
975
1025
1125
1200
1275
1325
1425
1475
1500
1550
1600
1675
1750
1825
1900
1950
Typical
-550
-450
-375
-300
-200
-125
-50
25
275
350
425
525
600
675
775
850
1300
1375
1470
1550
1650
1725
1800
1900
2000
2100
2200
2275
2375
2450
2550
2650
Max
-350
-275
-175
-100
-25
50
125
225
425
525
600
700
775
850
950
1025
1550
1650
1750
1825
1950
2025
2125
2200
2425
2525
2625
2700
2825
2925
3025
3125
Units
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
ppm/oC
Table 3 (left) illustrates the way the TC code affects the
sensitivity temperature drift. Also note in Table 3, the
overlap in TC codes. The numbers in the table represent
typical results and are for reference only. For accurate
results the TC code must be determined experimentally.
This TC code map applies to MLX90215’s with a first
line brand showing “215DB”
Special Note
The MLX90215 programmed with a zero TC code
(default) has a typical TC value between the range of –
300 to –600 ppm/oC. This means sensitivity will
decrease slightly as temperature increases. The slightly
negative initial TC value allows the MLX90215 to be
accurately programmed up to 0 TC. Almost all magnets
have a naturally negative TC code. The natural TC of a
magnet added with the initial negative TC value of the
MLX90215 could degrade linearity over a large
temperature span. Using a TC code of 6, 7, or 8 will
give the MLX90215 a slightly positive TC code.
Previous revisions of the MLX90215 with second line
brand of “15AXX” or “15DXX” should refer to factory
for TC code maps.
Diagnostic Characteristics
Page 4
Condition
Output Level
VOUT Shorted to VDD
VOUT = VDD
VOUT Shorted to VSS
VOUT = VSS
VOUT open with pull up load
VOUT = VDD
VOUT open with pull down load
VOUT = VSS
VSS open with pull up load
VOUT = VDD
VSS open with pull down load
> 10 K Ohms
VOUT = VDD
or 94% VDD
VDD open with pull up load
> 4.7 K Ohms
VOUT = VSS
or 3% VDD
VDD open with pull down load
VOUT = VSS
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
MLX90215 Performance
Typical Output Voltage versus
Magnetic Flux Density
Sensitivity = 10mV/mT
Typical Output Voltage versus
Magnetic Flux Density
Sensitivity = 140mV/mT
MLX90215
5
4
Output Voltage (V)
4
Output Voltage (V)
MLX90215
5
3
2
3
2
1
1
0
0
18
12
6
0
-6
3901090215
Rev 007
-12
-18
270
180
90
0
-90
-180
-270
Flux Density (mT)
Flux Density (mT)
Page 5
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
Melexis Programmer
Absolute Maximum Ratings
Melexis offers a programmer (PTC-01) for
programming the MLX90215. The PTC-01 comes
complete with windows based software that makes
programming the MLX90215 simple. The programmer
communicates with a PC via a RS232 serial interface.
The programmer and software allows users to load
settings
in the MLX90215, take measurements,
calibrate sensors, and program the MLX90215. For
more information the PTC-01 goto
www.melexis.com, or contact Melexis.
Left, PTC-01 windows
based software.
Works with any 9 Pin
Serial Port equipped
PC running windows
9x,W2000 or XP.
Supply Voltage (Over Voltage)
18V
Supply Voltage (Operating)
5V + 10%
Reverse Voltage Protection
-14.5V
Magnetic Flux Density
Unlimited
Supply Current, IDD
6.5 mA
Output Current (Short to VDD)
+12 mA
Output Current (Short to VSS)
-12 mA
Operating Temperature Range, TA
-40°C to 150°C
Storage Temperature Range, TS
-55°C to 165°C
ESD Sensitivity
+5kV
.
Melexis PTC-01
Programmer
3901090215
Rev 007
Page 6
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
Clamping the Output Voltage
The MLX90215 has a 2-bit CLAMP feature which
allows Four output voltage options. The CLAMP
feature is independent of the gain, and will not effect
sensitivity of the device. The table below illustrates
limits for each of the four options.
Bit Allocation Table
Bit
Function
1
INVERTSLOPE
2
OFFSETDAC 5
3
OFFSETDAC 6
4
OFFSETDAC 7
5
OFFSETDAC 8
6
OFFSETDAC 9
7
OFFSETDAC 4
8
OFFSETDAC 3
9
OFFSETDAC 2
10
OFFSETDAC 1
11
OFFSETDAC 0
12
FINEGAIN 0
13
FINEGAIN 1
14
FINEGAIN 2
15
HALFVDD
16
FINEGAIN 3
17
FINEGAIN 4
18
FINEGAIN 5
19
FINEGAIN 8
20
FINEGAIN 9
21
FINEGAIN 6
22
FINEGAIN 7
23
ROUGHGAIN 2
24
ROUGHGAIN 1
25
ROUGHGAIN 0
Installation Comments
26
TEMP CO 0
1.) Avoid mechanical stress on leads or package.
Stress may cause VOQ shift.
A.) Avoid bending leads at the package interface.
B.) Support the leads by clamping, when bending.
C.) Avoid gluing device to another material. This
may cause temperature-related stress.
2.) CMOS products are static sensitive devices, please
observe ESD precautions.
3.) Observe temperature limits during soldering.
27
TEMP CO 1
28
TEMP CO 2
29
TEMP CO 3
30
TEMP CO 4
31
CLAMP 1
32
CLAMP 0
33
MEMLOCK
34
TEST 0
35
TEST 1
36
TEST 2
37
TEST 3
Bit Value
0 (default)
1
2
3
Limits (% VDD)
no clamp
5 to 45
10 to 90
5 to 95
Application Comments
The following is a list of recommended operating
parameters that will help to ensure the accuracy and
stability of the MLX90215. These are not the absolute
programming limits of the device.
1.) Voq is best programmed in the absence of any
magnetic influence and to voltages closest to 1/2
VDD, where temperature drift will be +/-0.4% or
less. It is not recommended to use VOQ values close
to 0 volts or VDD when programming extremely
high sensitivity (> 100 mV/mT) values. Temperature instability may be observed on some devices
under these conditions.
2.) Best linearity of sensitivity is obtained when VOQ i s
programmed at 1/2VDD. This is with the 1/2VDD
function enabled.
3.) Best linearity of sensitivity is obtained when the
gain is programmed between 5mV/mT and
100mV/mT.
4.) Best temperature stability is realized when the
temperature compensation function is programmed
to zero ppm/oC.
5.) The Test/Readback pin is for diagnostic use only.
This pin is normally tied to GND. Contact Melexis
for more details on programming this device.
3901090215
Rev 007
Page 7
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
Physical Characteristics
3901090215
Rev 007
Page 8
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
Application Notes
Linear Precision Current Sensor
The Programmable gain, offset, and temperature
compensation of MLX90215 allows great flexiblity in
the design of a current sensor.
Current flowing through a conductor can produce a
proportional magnet field. The MLX90215 can then
produce an output voltage proportional to the current.
Using the programmable gain and offset function the
output of the MLX90215 can be adjusted to sense a
wide range of current allowing for a flexible design.
Slotted Torroid Example Assuming infinite
permeabilty of the core, the magnetic field through the
air gap produced by a single wire turn is given by
equation 2
Equation 2
B=
I
uo
lg
Where: I = current in Amperes
B = magnetic field in Tesla
lg = length of air gap in Meters
uo = Permeability of free space (4π10-7H/m)
This equation is a close estimate for the field in the air
gap, but does not take into account magnetic losses in
the core, fringing effects, and mechanical tolerances of
the air gap. The programmable MLX90215 can be
adjusted to compensate for these errors simplifying the
design. The temperature compensation of MLX90215
can also be adjusted to counteract temperature losses of
core.
Magnetic Suppliers:
Elna Ferrites Technologies Inc
Eastern Components
Fair Rite Products Corp
For sensing a current ±100A, with an air gap of 2mm
equation 2 yields a magnetic field range of ±63mT. The
output range of the MLX90215 is 0.5V to 4.5V (4V full
scale). Equations 3a and 3b yield a sensitivity of 32mV/
mT and a Voq of 2.5V.
Equation 3
a) S = 4000mV/ 126mT
b) Voq = 4V/2 + 0.5V
The resulting gain of the current sensor is 20mV/A with
an offset of 2.5V. For best results it is recommend that
MLX90215 be programmed with a Voq of 50% Vdd 1/2
Vdd bit set.
3901090215
Rev 007
Page 9
9/09/03
MLX90215
Precision Programmable
Linear Hall Effect Sensor
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/
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
E-mail: [email protected]
Phone: +1 603 223 2362
E-mail: [email protected]
QS9000, VDA6.1 and ISO14001 Certified
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.
3901090215
Rev 007
Page 10
9/09/03