MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
1. Features and Benefits
2. Application Examples
Analog Signal Processing
Quad Switched Hall Plate
Chopper Stabilized Amplifier
Linear Analog Ratiometric Output Voltage
Programmable Output Quiescent Voltage (VOQ)
-100%VDD…200%VDD Range
Programmable Magnetic Sensitivity
Programmable Low Pass Filter
Programmable Clamping Voltage
Programmable Temperature Compensation
Melexis ID Number
Programmable Customer ID Number
Lead-free package
Linear Position Sensing
Rotary Position Sensing
Current Sensing
Magnetic Field Measurement
Ordering Information
Product Code
MLX90251
MLX90251
MLX90251
MLX90251
MLX90251
MLX90251
MLX90251
MLX90251
Temperature Code
E
E
E
E
L
L
L
L
Legend:
Temperature Code:
Package Code
VA
VA
VA
VA
VA
VA
VA
VA
Option Code
FAA-000
FAA-100
FAA-200
FAA-300
FAA-000
FAA-100
FAA-200
FAA-300
Package Code:
Option Code:
Packing Form:
L for Temperature Range -40°C to 150°C
E for Temperature Range -40°C to 85°C
VA for Plastic Single in Line thickness 1.1-1.2mm
See section 12.4
BU for Bulk
Ordering example:
MLX90251LVA-FAA-000-BU
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3901090251
Packing Form Code
BU
BU
BU
BU
BU
BU
BU
BU
Page 1 / 22
MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
3. Functional Diagram
Supply
4. General Description
1
Filter
OPA
OPA
OPA
4
3
DAC
DAC
DAC
DAC
DAC
DAC
2
Shift Register
E E P R O M
Figure 1-1 Functional Diagram
VDD
Test
VSS (Ground)
VOUT
Pin Out
VA package
1
2
3
4
Program
decoder
The MLX90251 is a CMOS Programmable, Ratiometric
Linear Hall Effect sensor IC. The linear output voltage is
proportional to the magnetic flux density. The
ratiometric output voltage is proportional to the
supply voltage. The MLX90251 possesses active error
correction circuitry, which virtually eliminates the
offset errors normally associated with analog Hall
Effect devices. All the parameters of the MLX90251
transfer characteristic are fully programmable. The
VOQ (VOUT @ B = 0 Gauss), the Sensitivity, the slope
polarity, the Output Clamping levels, the thermal
Sensitivity drift, the internal bias point and a low-pass
filter are all programmable in end-user applications.
The MLX90251 has a very stable thermal
compensation for both the Sensitivity and the VOQ over
a broad temperature range. For traceability purpose
the MLX90251 will carry a unique ID number
programmed by Melexis and 24 bits of EEPROM
memory are allocated for a user programmed serial
number.
Table 1: Pin out
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
Table of Contents
1. Features and Benefits ................................................................................................................... 1
2. Application Examples .................................................................................................................... 1
3. Functional Diagram....................................................................................................................... 2
4. General Description ...................................................................................................................... 2
5. Glossary of Terms ......................................................................................................................... 4
6. Maximum Ratings ......................................................................................................................... 4
7. Detailed Block Diagram ................................................................................................................. 5
7.1. Detailed Description .................................................................................................................... 5
8. General Electrical Specifications ................................................................................................... 6
9. Programming Range ..................................................................................................................... 7
10. Timing Specifications .................................................................................................................. 7
11. Accuracy ..................................................................................................................................... 7
12. Programmable Features ............................................................................................................. 8
12.1. Output Quiescent Voltage (VOQ)................................................................................................ 9
12.2. Thermal VOQ Drift (DRIFT) .......................................................................................................... 9
12.3. Sensitivity, Rough Gain and Fine Gain ..................................................................................... 10
12.4. Sensitivity Range Selection ...................................................................................................... 11
12.5. Sensitivity Polarity (INVERT) .................................................................................................... 13
12.6. Clamping Levels (CLAMPLOW, CLAMPHIGH) .......................................................................... 13
12.7. Filter (FILTER) .......................................................................................................................... 14
12.8. Sensitivity Temperature Compensation (TC, TCW, TC2) .......................................................... 15
12.9. Diagnostic Output Level (FAULTLEV) ....................................................................................... 15
12.10. The EEPROM, Parity, and Melexis CRC .................................................................................. 15
12.11. Output Amplifier Configuration (MODE) ............................................................................... 16
12.12. Memory Lock (MEMLOCK) .................................................................................................... 16
12.13. IC traceability ........................................................................................................................ 16
13. Performance Graphs ................................................................................................................. 17
14. Applications Information........................................................................................................... 18
14.1. Application Circuits – VA-package ........................................................................................... 18
14.2. Programming the Sensor......................................................................................................... 18
14.3. Calibration Procedure ............................................................................................................. 19
15. Standard information regarding manufacturability of Melexis products with different soldering
processes ....................................................................................................................................... 20
16. ESD Precautions........................................................................................................................ 20
17. Package Information ................................................................................................................. 21
17.1. VA Package Outline and Hall Plate Position ............................................................................ 21
18. Contact ..................................................................................................................................... 22
19. Disclaimer................................................................................................................................. 22
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
5. Glossary of Terms
Term
Explanation
mT (milli-Tesla)
Unit of measurement for magnetic flux density. 1mT is equal to 10 Gauss.
VOQ (Output Quiescent Voltage)
Output voltage at zero magnetic field, VOUT for B = 0 mT.
Sensitivity
Change in output voltage versus change in magnetic field (Δ VOUT / Δ B)
TempCo (Sensitivity
Temperature Compensation)
PTC (Programming Through the
Connector)
Change in Sensitivity over temperature.
Listed in units of ppm / °C (where 100ppm / °C. = 0.01% / °C)
MSB
Most Significant Bit.
LSB
Least Significant Bit.
Melexis in-circuit programming protocol.
6. Maximum Ratings
Parameter
Units
Maximum Supply Voltage, VDD_MAX
(over Voltage)
30 V
Maximum Supply Current, IDD_MAX
(Over Voltage)
50 mA
Reverse Voltage, VDD_REV
- 15 V
Reverse Supply Current, IDD_REV
- 85 mA
Positive Output Voltage, VOUT_MAX
24 V
Positive Output Current, IOUT_POS_FAULT
40 mA
Reverse Output Voltage, VOUT_REV
- 0.7 V
Reverse Output Current, IOUT_REV_FAULT
-50 mA
Operating Ambient Temperature
Range, TA
-40°C to 150°C
Storage Temperature Range, TS
-55°C to 165°C
Magnetic Flux Density
Infinite
Table 2: Absolute Maximum Ratings
Note: Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute-maximum-rated
conditions for extended periods may affect device reliability.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
EEPROM
Current
Source
Hall
Plate
Chopper
Stabilized
Amplifier
InvertSlope
RG:
4 Bits
Sample & Hold
Filter
Offset Stage
Clamp
Stage
Output
Amplifier
Output
Analog Signal Processing
7. Detailed Block Diagram
TCW: 3 Bits
TC: 5 Bits
TC^2: 6 Bits
Lock Out:
MemLock
MLXLock
AGND:
10 Bits
CLAMP
Hi: 10 Bits
Lo: 10 Bits
FG:
10 Bits
FILTER:
4 Bits
OFFSET: 10 Bits
DRIFT: 4 Bits
MODE:
2 Bits
Fault
Level
Figure 5-1 Detailed Block Diagram
7.1. Detailed Description
Integrated on the MLX90251 is a temperature-compensated quad switched Hall plate, chopper
stabilized amplifiers, adjustable output filter, output driver, voltage protection circuitry and a
programmable EEPROM with security and redundancy. Programming the EEPROM allows each device to
be calibrated in the application.
In normal operation data stored in the EEPROM feeds a register, RAM that updates internal DACs and
switches that effect the operation of the device. In programming mode the RAM can be directly
accessed to allow faster calibration of the parameters. Communication to the device is done using
Melexis' PTC serial interface.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
8. General Electrical Specifications
DC operating parameters at VDD = 5V (unless otherwise specified) and for TA as specified by the
temperature range (E or L).
Parameter
Symbol
Nominal Supply Voltage
VDDNOM
Operating Supply Voltage
VDD
Nominal Supply Current
IDDNOM
Supply Current
Min
Typical
Max
Units
-
5
-
V
4.5
-
5.5
V
VDD = VDDNOM
4.0
7.0
8.0
mA
IDD
VDD = 4.5 … 5.5 V
3.0
-
9.0
mA
VOUTPD
Pull Down Load ≥ 10 kΩ
no clamping
2
96
%VDD
VOUTPU
Pull Up Load ≥ 10 kΩ
no clamping
5
97
%VDD
IOUT
VDD = VDDNOM
-1.25
1.25
mA
-12
4
-4
12
mA
mA
0.5
%VDD
1
Output Voltage Swing
Output Current
Output Short-Circuit
Current
Test Conditions
IOUTSC+
IOUTSC-
VDD = VDDNOM
Output shorted to supplypermanent
Output shorted to groundpermanent
VOUT1
Broken supply,
Pull-down load > 10 kΩ
0
VOUT2
Broken ground,
Pull-down load > 10 kΩ
94
96
100
%VDD
VOUT3
Broken supply,
Pull-up load > 10 kΩ
0
3
5
%VDD
VOUT4
Broken ground,
Pull-up load > 10 kΩ
99.5
100
%VDD
Power on Reset
VDD_POR
Voltage on VDD
1.5
3.8
V
Over Voltage Detection
VDD_OVD
Voltage on VDD
6.5
8.5
V
Diagnostic Output Voltage
Table 3: Electrical Specifications
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 are compensated.
1
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
9. Programming Range
TA programming 20°C to 30°C.
Parameter
Symbol
Test Conditions
Min
Output Quiescent Voltage
VOQ
AGND = Default
AGND = 0…1023
Sensitivity
S
Output Clamping Voltage
Low
ClampLo
Output Clamping Voltage
High
ClampHi
Temperature Compensation TempCo
Max
Units
-10
-100
110
200
%VDD
%VDD
2.6
210
mV/mT
0
100
%VDD
0
100
%VDD
0
2300
ppm / °C
1st order
Typical
Table 4: Programming Range Specifications
10. Timing Specifications
DC operating parameters at VDD = 5V (unless otherwise specified) and for TA as specified by the
temperature range (E or L).
Parameter
Symbol
Test Conditions
Power On Delay
TPO
FILTER = 0, RG = 0
FILTER = 0, RG = 15
FILTER = 15, RG = 0
FILTER = 15, RG = 15
Step Response Time
RG = 0 to 3, FILTER = 0
RG = 4 to 7, FILTER = 0
RG = 8 to 11, FILTER = 0
RG = 12 to 15, FILTER = 0
Min
Typical
Max
Units
0.4
0.6
1.1
5
0.8
1.2
2.2
10
ms
ms
ms
ms
32
64
132
264
μs
μs
μs
μs
24
48
100
200
Table 5: Timing Specifications
11. Accuracy
DC operating parameters at VDD = 5V (unless otherwise specified) and for TA as specified by the
temperature range (E or L).
Parameter
Symbol††
Test Conditions
Min
Thermal Voq Drift
Δ VOQ
VOQ = 2.5V , 25°C / 150°C
VOQ = 2.5V2, 25°C / -40°C
T
Life Time Drift of the L T
Δ Δ VOQ
Thermal Voq Drift
Life Time Voq Drift
ΔLΔVOQ
Life Time Sensitivity Drift
ΔLΔS
2
2
Typical
Max
Units
- 0.2
- 0.4
+ 0.2
+ 0.4
%VDD
%VDD
- 0.2
+ 0.2
%VDD
- 0.3
-1
+ 0.3
+1
%VDD
%
For other test conditions, please contact the Melexis Sales representative of your area.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
Parameter
Symbol††
Sensitivity
Coefficient 3
Test Conditions
Temperature TCs
Thermal Drift of Sensitivity
Temperature Compensation
Thermal
Drift
Output
Clamping Levels
Life Time Drift Output
Clamping Levels 4
Linearity error
ΔTTC
ΔTVOUTCLAMP
0 to 500 ppm / °C
500 to 1200 ppm / °C
1200 to 2300 ppm / °C
VA-package
GO-package
ΔLVOUTCLAMP
Min
Max
Units
ppm / °C
ppm / °C
ppm / °C
ppm / °C
- 0.4
± 100
± 150
± 200
150
250
+ 0.4
- 0.2
+ 0.2
%VDD
Le
Typical
0.2
%VDD
%
Table 6: Accuracy Specifications
12. Programmable Features
The MLX90251 has many programmable features for adjusting the output characteristic. The features
are utilized by writing data into the redundant non-volatile EEPROM. Below is a quick list and
description of all the programmable parameters. Many of the parameters are set by Melexis and they
are not used by the end customer. Later sections of the data sheet give details on how the parameters
are used.
Parameter
Symbol
Description
Number of Bits
Default
AGND
Coarse adjustment of VOQ.
10
Trimmed
Analog Clock Choice
CKANACH
Adjustment for amplifier clock generator.
2
Preset
Clamping High
CLAMPHIGH Adjustment of upper output clamping
voltage.
10
512
Clamping Low
CLAMPLOW Adjustment of lower output clamping
voltage.
10
512
Customer ID††
CUSTID
Open bits for customer’s ID
programming.
24
Preset
Offset Drift†
DRIFT
VOQ temperature drift compensation.
4
Trimmed
EEPROM Fault Level
FAULTLEV
Output state for EEPROM parity error.
1
0
Fine Gain
FG
Fine adjustment for Sensitivity.
10
0
Filter
FILTER
Adjustment for low pass output filter.
4
0
Invert Slope
INVERT
Sensitivity polarity selection.
1
0
Memory Lock
MEM_LOCK Used to lock the entire EEPROM.
1
0
Melexis ID
MLX_ID
Melexis IC identification number.
MLX_LOCK
Used to lock Melexis area of the EEPROM.
1
0
MODE
Adjustment for output stage amplifier.
2
1
OFFSET
Fine adjustment of VOQ.
10
0
OSCADJ
Chip oscillator frequency adjustment.
4
Preset
Internal Bias Point
†
†
Melexis Lock
†
Output Driver
†
Offset DAC
Oscillator Adjust
3
4
†
Preset
Valid for Rough Gain within the specified option code.
∆L = Life Time Drift (based on HTOL data [1000 hours @ 150°C]).
∆T = Thermal Drift.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
Parameter
Symbol
Description
Number of Bits
Default
EEPROM Parity
PARITY
Ensures the integrity of the EEPROM data.
3
Calculated
Rough Gain
RG
Rough adjustment for Sensitivity.
4
0
Slow
SLOW
Amplifier speed adjustment.
1
Preset
Temperature
Compensation Window
TCW
Range adjustment for Sensitivity
Temperature Compensation.
3
0
Temperature
Compensation
TC
Fine adjustment of Sensitivity
Temperature Compensation.
5
0
Linearization adjustment of the Sensitivity
Temperature Compensation.
6
0
†
2nd Order Temperature TC2
Compensations
Table 7: Programmable Parameters
†
Melexis parameter adjusted at final test.
Not included in redundant area of the EEPROM.
††
12.1. Output Quiescent Voltage (VOQ)
Two parameters, AGND and OFFSET, are used for adjustment of the VOQ. The AGND is a 10 bit
parameter for coarse adjustment of VOQ. It has a resolution of approximately 0.014V and a range from 100%VDD to 200%VDD. The OFFSET is a 10 bit parameter with a resolution of approximately -0.005V.
The OFFSET parameter is used for fine adjustment of the VOQ, while the AGND parameter is used to set
the range. The large adjustable range allows the MLX90251 to be used in an unipolar magnetic system
without limiting the output voltage span. The formula below shows how the AGND and OFFSET
parameters combine to set the VOQ.
14.25V
5.0V
∗ AGND + −
∗ OFFSET
VOQ = −0.75V +
1023
1023
VDD =5.00V
This formula approximates the typical VOQ of the MLX90251. The actual VOQ formula varies slightly from
chip to chip. Melexis calibrates the AGND setting during final test so that the VOQ is approximately
50%VDD with OFFSET set to 512. This gives the VOQ a range of 0%VDD to 100%VDD without adjusting the
AGND value. The OFFSET parameter is often used to set the offset in the application's output transfer
characteristic.
12.2. Thermal VOQ Drift (DRIFT)
The Thermal VOQ Drift is tuned using 4 bits. This parameter, DRIFT, is calibrated for each unit by Melexis
during final test. The value is set to achieve a VOQ accuracy below 10mV over a temperature span of
25°C to 150°C. This parameter is not used by the end customer.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
12.3. Sensitivity, Rough Gain and Fine Gain
The Sensitivity of the MLX90251 is controlled through parameters linked to dedicated internal
amplification stages. The parameter Rough Gain (RG), or pre-amplifier, has 4 bits for adjustment of two
stages. The two MSB affect the Differential Input Differential Output (DIDO) stage. The two LSB effect
the Differential to Single output (DTS) stage. The gain of both the DIDO and DTS are multiplied to get
the total RG. The table below shows the theoretical small signal amplifier gain vs. the parameter RG.
The pre-amplifier is chopper stabilized and the refresh frequency is adapted automatically to the RG
setting to match the chopper gain-bandwidth product.
Rough Gain (MSB LSB)
DIDO
DTS
Gain
00 (00 00)
01 (00 01)
02 (00 10)
03 (00 11)
04 (01 00)
05 (01 01)
06 (01 10)
07 (01 11)
08 (10 00)
09 (10 01)
10 (10 10)
11 (10 11)
12 (11 00)
13 (11 01)
14 (11 10)
15 (11 11)
16
16
16
16
39
39
39
39
82
82
82
82
205
205
205
205
1.0
1.5
2.33
4.0
1.0
1.5
2.33
4.0
1.0
1.5
2.33
4.0
1.0
1.5
2.33
4.0
16
24
37
64
39
59
91
156
82
123
191
328
205
308
477
820
Table 8: MLX90251 Rough Gain Small Signal Amplifier Gain
The MLX90251 also has an additional stage, Fine Gain, for fine tuning the Sensitivity. The stage
(parameter FG) follows the RG and provides a 10 bit adjustment. The small signal gain of the FG is
within 1.0 and 2.5. The RG and FG parameters are adjusted in the application to calibrate the device's
sensitivity (gain) and output slope transfer characteristic. The function for the fine gain is given in the
following equation:
Fine Gain =
1
1 − 0.6 *
FG
1023
Note. The one bit parameter INVERT is used to fix the “sign” of the sensitivity. A value of 0 makes the Sensitivity
positive and the output voltage increases in response to an increasing South magnetic field. A value of 1 makes the
Sensitivity negative and the output voltage decreases in response to an increasing South magnetic field. Refer to
section 12.5, Sensitivity Polarity, for more information on INVERT.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
12.4. Sensitivity Range Selection
Each unit is characterized over temperature during final test to optimize its performance and accuracy.
To achieve the best possible Sensitivity Temperature Compensation, TempCo, each unit is optimized for
use within a specific Sensitivity range. This is represented in the ordering information by the option
code. There are four available ranges, option codes 0, 1, 2 and 3. The option code corresponds with
the two MSB of the RG parameter. Each device is tested to meet the TempCo specification in the
Sensitivity range determined by the RG parameter (RG = 0...3, RG = 4…7, RG = 8…11 or RG = 12…15),
regardless of the FG parameter.
Option Code
Rough Gain
xxx-000
xxx-100
xxx-200
xxx-300
0-3 (00 xx)
4-7 (01 xx)
8-11 (10 xx)
12-15 (11 xx)
Sensitivity Range
(mV/mT)
2.6 < S < 15
10 < S < 35
18 < S < 90
50 < S < 210
Typical Magnetic Field Range
(mT, BMAX - BMIN)
333 < B < 800
156 < B < 333
62 < B < 156
6 < B < 62
Table 9: Optimized Sensitivity Range (Rough Gain = RG)
The next figures show the typical Sensitivity versus the FG and RG parameters. The gray areas are
representative of the chip to chip dispersion (i.e.: for the same RG and FG parameters, the Sensitivity
can vary from chip to chip). There is a large overlap between the different ranges for use of one range
for applications with large magnetic and/or mechanical dispersions. The Sensitivity graphs and tables
can be used to select the right device type for the application. If one is unsure of the applications
magnetic design and the desired Sensitivity range Melexis recommends option code 2.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
Figures 10.4-1…10.4-4 Sensitivity versus RG and FG, The first (bold) digit in Table 9 is the sensitivity range.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
12.5. Sensitivity Polarity (INVERT)
The slope transfer characteristic defines the Sensitivity. The INVERT parameter changes the
Sensitivity's polarity, or the slope's direction. This allows the device to accommodate the application
requirements and the magnet's polarity. The slope is inverted in the first stage of the IC, at the Hall
plate. With INVERT set to 0, the output voltage increases when an increasing South magnetic field is
applied and decreases in the presence of an increasing North magnetic field. An INVERT value of 1
causes the output voltage to increase in the presence of a North magnetic field and decrease in the
presence of a South magnetic field. The magnetic field polarity is referenced to the field component
perpendicular to the top-face of the MLX90251.
12.6. Clamping Levels (CLAMPLOW, CLAMPHIGH)
Two independent values, called the clamping levels, can limit the output voltage range or swing. The
CLAMPLOW parameter adjusts the minimum output voltage level, ClampLo. The CLAMPHIGH sets the
maximum output voltage level, ClampHi. Both parameters have 10 bits of adjustment with a resolution
of approximately 0.005V. The formulas below give a close approximation of the output clamp voltage.
The actual clamping level formulas vary slightly from chip to chip. If CLAMPLOW exceeds CLAMPHIGH
the output voltage is fixed at the high clamp voltage level. The CLAMPHIGH and CLAMPLOW have an
initial value of 512, set by Melexis. This results in a fixed output voltage of approximately 50% VDD.
ClampLo =
5.10V
∗ CLAMPLOW
1023
V DD = 5.00V
ClampHi =
5.10V
∗ CLAMPHIGH
1023
V DD = 5.00V
At the point the output voltage switches between the linear operating region and the clamping region
the output can deviate slightly. This is represented by the grey areas in the figure below. The limits for
deviation in the Y axis are listed in Table 10. The deviation in the X axis is calculated from the
application's transfer function. The Clamp Comparator Offset does not affect the output linearity or
clamp voltage accuracy. During calibration it is recommended to set the clamp voltage outside of the
transition region (0V to 5V).
VOUT
CLAMP HIGH
Linear Operating
Region
CLAMP LOW
Transition Point
FIELD
Figure 10.6 Output Voltage Clamping Deviation
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
DC operating parameters at VDD = 5V (unless otherwise specified) and for TA as specified by the
temperature range (E or L).
Parameter
Symbol
Clamp Comparator Offset
CLAMPOFF
Test Conditions
Min
Typical
- 0.7
Max
Units
+ 0.7
%VDD
Table 10: Clamp Comparator Offset Specification
12.7. Filter (FILTER)
The MLX90251 includes two programmable low-pass filters located within the chopper amplifier stages.
The two low-pass filters are controlled through a 4 bit parameter, FILTER. The FILTER value 0
corresponds to minimum filtering, maximum speed (impulse response time), and maximum output
noise. The value 15 provides the maximum filtering, minimum speed, and minimum output noise. It is
important to note the noise is also linked to the gain settings. The FILTER parameter needs to be
adjusted to achieve optimal performance. The next table shows typical values the cut-off frequency at
-3 dB versus FILTER and RG parameters. FILTER values from 8 to 11 are not used. For most applications
FILTER values 7 or 15 are recommended.
Cut-off frequency at -3 dB (Hz) – Typical
Filter
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
MLX90251-000
Rough Gain 0…3
22900
19500
12300
10400
7450
5850
5700
5050
2200
1000
920
800
MLX90251-100
Rough Gain 4…7
14300
11450
10000
6750
3900
2900
2700
2550
840
480
380
330
MLX90251-200
Rough Gain 8…11
7000
5550
3000
2100
1500
1125
1350
1380
Not used
Not used
Not used
Not used
565
470
290
250
MLX90251-300
Rough Gain 12…15
3850
2950
2300
1100
850
860
715
650
250
190
155
135
Table 11: Cut-off Frequency versus FILTER and RG Parameters
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
12.8. Sensitivity Temperature Compensation (TC, TCW, TC2)
The change in the device's Sensitivity versus temperature is defined as the Sensitivity Temperature
Compensation, TempCo. In an application the slope output transfer characteristic is often affected by
temperature. Fluctuations in temperature can cause variations in the air gap, mechanical alignment
and magnetic field. The Sensitivity Temperature Compensation feature compensates for these effects.
Three parameters, TC, TCW, TC2 are used for adjustment of the TempCo. The TCW is used to adjust the
TempCo range, TC is for fine adjustment of the TempCo value, and TC2 effects the TempCo linear
response. To simplify use of these parameters Melexis stores a look up table within the EEPROM of
each device. The look up table is optimized for each device by characterizing the unit over temperature
at final test.
The value of TempCo is often determined by the magnet. In the application the TempCo is adjusted to
compensate for the temperature coefficient of the magnet. To adjust the value the look up table is
read from the device. The parameters are then calculated to match the desired value. The Melexis PTC
hardware and software tools contain built in functions for programming the TempCo.
TempCo Range (ppm / °C)
Accuracy (ppm / °C)
0 to 500
500 to 1200
1200 to 2000
± 100
± 150
± 200
Table 12: TempCo Accuracy
Note: The budget error of the whole system, the compensation mismatch (system Vs. IC) tolerance should be taken into
consideration during the design. Table 11 is valid for Rough Gain within the specified option code. See section 12.4 for
information on selecting the option code.
12.9. Diagnostic Output Level (FAULTLEV)
The MLX90251 EEPROM memory content is secured through a parity check. This self-diagnostic feature
brings the output to a defined range in case of a parity error. The parameter, FAULTLEV, is used to
define the parity error diagnostic state. With the FAULTLEV set to 0 a parity error event will result in an
output diagnostic voltage low. With the FAULTLEV set to 1 a parity error event will result in an output
diagnostic voltage high. To get rid of the output load influence the output diagnostic voltage level can
be fixed to either Ground (to be used with pull-down load) or VDD (to be used with pull-up load).
Melexis PTC software and hardware tools have built in functions for calculating and programming the
parity.
Note: The MLX90251 EEPROM is also redundant. Each parameter bit is written in three separate cells and a “majority
voting” is applied to determine its status. A parity error is detected only if two out of the three cells unexpectedly
change state. The bits available for the customer ID are not redundant.
12.10. The EEPROM, Parity, and Melexis CRC
The memory cells of the EEPROM are arranged in a table of four columns and one hundred twenty
eight rows. This configuration gives redundancy to the parameters stored in the EEPROM. Each
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Programmable Linear Hall Effect Sensor
Datasheet
parameter bit is written in three separate cells in an individual row. A majority voting applied to the
three cells determines the logic status of the bit.
A parameter bit only toggles state in error if two out of three memory cells, within a row, unexpectedly
change. If this happens the feature, PARITY, forces the output voltage to the FAULTLEV diagnostic
level. This ensures the device does not operate with a critical memory fault.
The remaining memory cells are used for data storage. The status of these cells does not effect the
device operation. For example the Customer ID, CUSTID, is stored in this area. Melexis stores the
device ID information, TempCo look-up table and CRC bits in the extra cells. The CRC bits ensure the
integrity of the Melexis data.
Note: To avoid parity and CRC errors, the entire contents of the EEPROM must be read before programming. Melexis
PTC software and hardware tools have built in functions for reading the EEPROM and handling parity.
12.11. Output Amplifier Configuration (MODE)
The output buffer can be configured to accommodate capacitive loads and improve the saturation
voltage (output swing). The two bit parameter, MODE, sets the current capacity of the output
amplifier. Melexis sets this parameter to 1 at final test. This parameter is not used by the end
customer.
12.12. Memory Lock (MEMLOCK)
The Memory Lock feature prevents the device from entering programming mode and from any changes
to the EEPROM. The entire EEPROM is locked by setting the MEMLOCK parameter to 1. This should be
the last parameter set in the application.
12.13. IC traceability
A unique ID number is programmed into the EEPROM of every IC. The ID number gives Melexis
additional traceability to better service its customers. The ID number is composed of the lot number,
wafer number, and wafer coordinates (X and Y). Memory is also available for the customer to add a
serial number of the product or any other data.
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
13. Performance Graphs
Typical I DD VS VDD
Typical I DD VS VDDNOM
60
8.5
8
Over Voltage
40
V DDNOM
7.5
Under Voltage
20
6.5
DD
(mA)
0
-20
I
I
DD
(mA)
7
6
-40
5.5
150°C
-40°C
25°C
-60
-80
-10
0
10
20
150°C
-40°C
25°C
5
30
4.5
4
VDD (Volts)
4.5
5
5.5
VDD (Volts)
Figure 11-1…11-2 IDD Versus VDD
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
14. Applications Information
14.1. Application Circuits – VA-package
Pin 2, TEST, is not used in applications. For EMC protection it is recommended to connect pin 2 to pin 3,
Ground, as close as possible to the device pins. The values for capacitors, C1 and C2, can be adjusted to
satisfy ESD and EMC requirements according to the environment. Ceramic capacitors are recommended
for use in the application. However for stable operation, the global output capacitor (C2 + C3) should
not be higher than 150nF. If higher capacitors (due to special ESD or EMC requirements) or special
circuit configurations are requested, please contact Melexis.
The MLX90251 can operate with a high impedance load and C2, a load resistor is not required.
VDD
VDD
MLX90251
1
2
3
MLX90251
A/D
µC
4
1
2
3
R
10k
4
VOUT
C1
100nF
VOUT
C3
C2
100nF
A/D
µC
4.7nF
GND
R
10k
C1
C2
C3
100nF
100nF GND
4.7nF
Pull-Down Load
Pull-Up Load
Figures 12.1-1…12.1-2 Application Circuits
A voltage of 9V is required on VDD for programming. All additional components connected to VDD must
be able to withstand the voltage. The MLX90251 is designed for operation with a stable 5V supply. If
fast voltage transients occur additional filtering may be required.
14.2. Programming the Sensor
To program the MLX90251 connection to VDD, GND, and VOUT is required. The device is placed into
program mode by increasing the supply voltage to the VDD program level. In program mode data is
clocked into the device through the output pin using the Melexis tri-level PTC protocol. The clock and
data are integrated into one serial data stream, eliminating the need for a dedicated clock signal. The
data is clocked at the leading edge of each bit.
5.0V
VOUT
Program Wave Form
2.5V
0V
9.0V
VDD Program
Device
Decoded
Clock
5.0V
Device
Decoded
Data
Figure 12.2-1 VDD Programming Level
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3901090251
X
1
X
0
X
Figure 12.2-2 Tri-Level PTC
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
Note: External capacitors and resistors will affect the rise and fall times for the programming
waveforms. Program pulse timings may require adjustment for the application. The device cannot be
programmed if MEMLOCK equals 1.
The EEPROM contents can be read from the device. This procedure, known as a read back, is done by
sending a read command and then measuring the supply current. To successfully read the EEPROM it
must be possible to measure the supply current to the device. The Melexis PTC hardware and software
tools contain built in functions for reading the EEPROM.
The MLX90251 can be programmed by using the PTC-04 programmer and the dedicated software tools.
The timing and voltage levels are controlled through the programming hardware and software. Further
details can be found in the MLX90251 software documentation.
14.3. Calibration Procedure
The programmable features of the device allow for calibration within the application. This section gives
general information for a two point calibration procedure. The two point calibration is the most
common however, it is possible to adapt other procedures.
1.) The first step in the calibration procedure is to initialize the device. This is done by establishing
communication and reading the contents of the EEPROM.
2.) The second step is to set the TempCo and FILTER settings.
3.) Step three is the evaluation of position one. During this step the output voltage is measured with
initial values for RG, FG and OFFSET.
4.) Step four is the evaluation of position two. During this step, the output voltage is measured with
the same values from step 3. From the measurements it is possible to calculate the slope and offset
error. Next the output slope transfer characteristic versus FG and RG is interpolated. With this
information the initial settings are adjusted and the output voltage is measured again.
5.) Step five is the final check and adjustment. At this stage small corrections are made to the OFFSET
and FG parameters. Next, the output clamping parameters, CLAMPHIGH and CLAMPLOW, are
determined.
6.) The sixth step is the program phase. Now that all the parameters are determined and the
application requirements are satisfied, the settings are programmed into the EEPROM.
7.) The final step, seven, is the lock and verify step. Here the customer can perform any number of
additional measurements and verify the EEPROM contents. After this is completed the MEMLOCK is set
and the EEPROM is locked, preventing any further programming.
Note: EEPROM verification is done by reading the contents of the EEPROM and comparing it to the data
written. It is possible to read the EEPROM contents regardless of the status of MEMLOCK.
The Melexis PTC software tools contain built in functions and procedures for calibrating the MLX90251.
Please refer to the software documentation for more information on how to use the calibration tools.
The output of the MLX90251 is ratiometric. To avoid calibration errors from fluctuations in the supply
voltage, the output voltage should be measured as a percentage of the supply voltage.
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Programmable Linear Hall Effect Sensor
Datasheet
15. Standard information regarding manufacturability of Melexis
products with different soldering processes
Our products are classified and qualified regarding soldering technology, solder ability and moisture
sensitivity level according to standards in place in Semiconductor industry.
For further details about test method references and for compliance verification of selected soldering
method for product integration, Melexis recommends reviewing on our web site the General
Guidelines soldering recommendation. For all soldering technologies deviating from the one mentioned
in above document (regarding peak temperature, temperature gradient, temperature profile etc),
additional classification and qualification tests have to be agreed upon with Melexis.
For package technology embedding trim and form post-delivery capability, Melexis recommends to
consult the dedicated trim & form recommendation application note: lead trimming and forming
recommendations
Melexis is contributing to global environmental conservation by promoting lead free solutions. For
more information on qualifications of RoHS compliant products (RoHS = European directive on the
Restriction Of the use of certain Hazardous Substances) please visit the quality page on our
website: http://www.melexis.com/en/quality-environment
16. ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
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Programmable Linear Hall Effect Sensor
Datasheet
17. Package Information
VA-package: the lead-free VA-package is released for MSL1/245°C.
17.1. VA Package Outline and Hall Plate Position
Hall Plate Position
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MLX90251
Programmable Linear Hall Effect Sensor
Datasheet
18. Contact
For the latest version of this document, go to our website at www.melexis.com.
For additional information, please contact our Direct Sales team and get help for your specific needs:
Europe, Africa
Telephone: +32 13 67 04 95
Email : sales_europe@melexis.com
Americas
Telephone: +1 603 223 2362
Email : sales_usa@melexis.com
Asia
Email : sales_asia@melexis.com
19. Disclaimer
The content of this document is believed to be correct and accurate. However, the content of this document is furnished "as is" for informational use only and no
representation, nor warranty is provided by Melexis about its accuracy, nor about the results of its implementation. Melexis assumes no responsibility or liability for any
errors or inaccuracies that may appear in this document. Customer will follow the practices contained in this document under its sole responsibility. This documentation is
in fact provided without warranty, term, or condition of any kind, either implied or expressed, including but not limited to warranties of merchantability, satisfactory
quality, non-infringement, and fitness for purpose. Melexis, its employees and agents and its affiliates' and their employees and agents will not be responsible for any loss,
however arising, from the use of, or reliance on this document. Notwithstanding the foregoing, contractual obligations expressly undertaken in writing by Melexis prevail
over this disclaimer.
This document is subject to change without notice, and should not be construed as a commitment by Melexis. Therefore, before placing orders or prior to designing the
product into a system, users or any third party should obtain the latest version of the relevant information.
Users or any third party must determine the suitability of the product described in this document for its application, including the level of reliability required and determine
whether it is fit for a particular purpose.
This document as well as the product here described may be subject to export control regulations. Be aware that export might require a prior authorization from
competent authorities. The product is not designed, authorized or warranted to be suitable in applications requiring extended temperature range and/or unusual
environmental requirements. High reliability applications, such as medical life-support or life-sustaining equipment or avionics application are specifically excluded by
Melexis. The product may not be used for the following applications subject to export control regulations: the development, production, processing, operation,
maintenance, storage, recognition or proliferation of:
1. chemical, biological or nuclear weapons, or for the development, production, maintenance or storage of missiles for such weapons;
2. civil firearms, including spare parts or ammunition for such arms;
3. defense related products, or other material for military use or for law enforcement;
4. any applications that, alone or in combination with other goods, substances or organisms could cause serious harm to persons or goods and that can be used as a
means of violence in an armed conflict or any similar violent situation.
No license nor any other right or interest is granted to any of Melexis' or third party's intellectual property rights.
If this document is marked “restricted” or with similar words, or if in any case the content of this document is to be reasonably understood as being confidential, the
recipient of this document shall not communicate, nor disclose to any third party, any part of the document without Melexis’ express written consent. The recipient shall
take all necessary measures to apply and preserve the confidential character of the document. In particular, the recipient shall (i) hold document in confidence with at least
the same degree of care by which it maintains the confidentiality of its own proprietary and confidential information, but no less than reasonable care; (ii) restrict the
disclosure of the document solely to its employees for the purpose for which this document was received, on a strictly need to know basis and providing that such persons
to whom the document is disclosed are bound by confidentiality terms substantially similar to those in this disclaimer; (iii) use the document only in connection with the
purpose for which this document was received, and reproduce document only to the extent necessary for such purposes; (iv) not use the document for commercial
purposes or to the detriment of Melexis or its customers. The confidentiality obligations set forth in this disclaimer will have indefinite duration and in any case they will be
effective for no less than 10 years from the receipt of this document.
This disclaimer will be governed by and construed in accordance with Belgian law and any disputes relating to this disclaimer will be subject to the exclusive jurisdiction of
the courts of Brussels, Belgium.
The invalidity or ineffectiveness of any of the provisions of this disclaimer does not affect the validity or effectiveness of the other provisions.
The previous versions of this document are repealed.
Melexis © - No part of this document may be reproduced without the prior written consent of Melexis. (2021)
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