MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 1 of 19 Data Sheet
Rev 010 Oct/11
Features and Benefits
Analog Signal Processing
Quad Switched Hall Plate
Chopper Stabilized Amplifier
Linear Analog Ratiometric Output Voltage
Programmable Output Quiescent Voltage (V
OQ
)
-100%V
DD
…200%V
DD
Range
Programmable Magnetic Sensitivity
Programmable Low Pass Filter
Programmable Clamping Voltage
Programmable Temperature Compensation
Melexis ID Number
Programmable Customer ID Number
Lead-free package
Application Examples
Linear Position Sensing
Rotary Position Sensing
Current Sensing
Magnetic Field Measurement
Ordering Information
Part No. Temperature Code Package
Code Option Code
††
MLX90251 E (-40°C to 8C) VA (4 Lead SIP) 0, 1, 2, 3
L (-40°C to 150°C)
Example:
MLX90251LVA-2
The VA package type is lead-free (see section 15).
††
Please see section 10.4 for detailed information on the option code.
1 Functional Diagram
OPA
DAC
Shift Register
E E P R O M
OPA
OPA
3
DAC
DAC
DAC
Filter
DAC
Supply
1
4
Program
decoder
2
DAC
Figure 1-1 Functional Diagram
Pin Out
VA package
V
DD
1
Test
2
V
SS
(Ground)
3
V
OUT
4
2 General Description
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 V
OQ
(V
OUT
@ 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 V
OQ
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
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 2 of 19 Data Sheet
Rev 010 Oct/11
Table of Contents
1 Functional Diagram ........................................................................................................... 1
2 General Description .......................................................................................................... 1
3 Glossary of Terms ............................................................................................................. 3
4 Maximum Ratings ............................................................................................................. 3
5 Detailed Block Diagram ..................................................................................................... 4
5.1 Detailed Description .................................................................................................... 4
6 General Electrical Specifications ....................................................................................... 5
7 Programming Range ......................................................................................................... 6
8 Timing Specifications ........................................................................................................ 6
9 Accuracy ........................................................................................................................... 6
10 Programmable Features ................................................................................................. 7
10.1 Output Quiescent Voltage (V
OQ
) ................................................................................ 8
10.2 Thermal V
OQ
Drift (DRIFT) ........................................................................................ 8
10.3 Sensitivity, Rough Gain and Fine Gain ..................................................................... 8
10.4 Sensitivity Range Selection ....................................................................................... 9
10.5 Sensitivity Polarity (INVERT)................................................................................... 11
10.6 Clamping Levels (CLAMPLOW, CLAMPHIGH) ....................................................... 11
10.7 Filter (FILTER) ........................................................................................................ 12
10.8 Sensitivity Temperature Compensation (TC, TCW, TC
2
) ........................................ 12
10.9 Diagnostic Output Level (FAULTLEV) ..................................................................... 13
10.10 The EEPROM, Parity, and Melexis CRC .............................................................. 13
10.11 Output Amplifier Configuration (MODE) ................................................................ 13
10.12 Memory Lock (MEMLOCK) ................................................................................... 13
10.13 IC traceability ........................................................................................................ 14
11 Performance Graphs ..................................................................................................... 14
12 Applications Information ................................................................................................ 15
12.1 Application Circuits – VA-package .......................................................................... 15
12.2 Programming the Sensor ........................................................................................ 15
12.3 Calibration Procedure ............................................................................................. 16
13 Standard information regarding manufacturability of Melexis products with different
soldering processes ........................................................................................................... 17
14 ESD Precautions ........................................................................................................... 17
15 Package Information ..................................................................................................... 18
15.1 VA Package Outline and Hall Plate Position ........................................................... 18
16 Disclaimer ..................................................................................................................... 19
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 3 of 19 Data Sheet
Rev 010 Oct/11
3 Glossary of Terms
Term Explanation
mT (milli-Tesla) Unit of measurement for magnetic flux density. 1mT is equal to 10 Gauss.
V
OQ
(Output Quiescent
Voltage) Output voltage at zero magnetic field, V
OUT
for B = 0 mT.
Sensitivity Change in output voltage versus change in magnetic field ( V
OUT
/ B)
TempCo (Sensitivity
Temperature Compensation)
Change in Sensitivity over temperature.
Listed in units of ppm / °C (where 100ppm / °C. = 0.01% / °C)
PTC (Programming Through
the Connector) Melexis in-circuit programming protocol.
MSB Most Significant Bit.
LSB Least Significant Bit.
4 Maximum Ratings
Parameter Units
Maximum Supply Voltage, V
DD_MAX
(over
Voltage)
30 V
Maximum Supply Current, I
DD_MAX
(Over Voltage)
50 mA
Reverse Voltage, V
DD_REV
- 15 V
Reverse Supply Current, I
DD_REV
- 85 mA
Positive Output Voltage, V
OUT_MAX
24 V
Positive Output Current, I
OUT_POS_FAULT
40 mA
Reverse Output Voltage, V
OUT_REV
- 0.7 V
Reverse Output Current, I
OUT_REV_FAULT
-50 mA
Operating Ambient Temperature Range, T
A
-40°C to 150°C
Storage Temperature Range, T
S
-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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 4 of 19 Data Sheet
Rev 010 Oct/11
5 Detailed Block Diagram
Figure 5-1 Detailed Block Diagram
5.1 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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 5 of 19 Data Sheet
Rev 010 Oct/11
6 General Electrical Specifications
DC operating parameters at V
DD
= 5V (unless otherwise specified) and for T
A
as specified by the temperature
range (E or L).
Parameter Symbol Test Conditions Min Typical
Max Units
Nominal Supply Voltage V
DDNOM
- 5 - V
Operating Supply Voltage V
DD
4.5 - 5.5 V
Nominal Supply Current I
DDNOM
V
DD
= V
DDNOM
4.0 7.0 8.0 mA
Supply Current I
DD
V
DD
= 4.5 … 5.5 V 3.0 - 9.0 mA
Output Voltage Swing
V
OUTPD
Pull Down Load ≥ 10 kΩ
no clamping 2 96 %V
DD
V
OUTPU
Pull Up Load ≥ 10 kΩ
no clamping 5 97 %V
DD
Output Current I
OUT
V
DD
= V
DDNOM
-1.25 1.25 mA
Output Short-Circuit Current
I
OUTSC+
I
OUTSC-
V
DD
= V
DDNOM
Output shorted to supply-permanent
Output shorted to ground-permanent
-12
4
-4
12
mA
mA
Diagnostic Output Voltage
V
OUT1
Broken supply,
Pull-down load > 10 kΩ 0 0.5 %V
DD
%V
DD
%V
DD
%V
DD
V
OUT2
Broken ground,
Pull-down load > 10 kΩ 94 96 100
V
OUT3
Broken supply,
Pull-up load > 10 kΩ 0 3 5
V
OUT4
Broken ground,
Pull-up load > 10 kΩ 99.5 100
Power on Reset V
DD_POR
Voltage on V
DD
1.5 3.8 V
Over Voltage Detection V
DD_OVD
Voltage on V
DD
6.5 8.5 V
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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 6 of 19 Data Sheet
Rev 010 Oct/11
7 Programming Range
T
A
programming 20°C to 30°C.
Parameter Symbol Test Conditions Min Typical
Max Units
Output Quiescent Voltage V
OQ
AGND = Default
AGND = 0…1023
-10
-100
110
200
%V
DD
%V
DD
Sensitivity S 2.6 210 mV/mT
Output Clamping Voltage Low ClampLo 0 100 %V
DD
Output Clamping Voltage High ClampHi 0 100 %V
DD
Temperature Compensation TempCo 1
st
order 0 2300 ppm / °C
Table 4: Programming Range Specifications
8 Timing Specifications
DC operating parameters at V
DD
= 5V (unless otherwise specified) and for T
A
as specified by the temperature
range (E or L).
Parameter Symbol Test Conditions Min Typical
Max Units
Power On Delay T
PO
FILTER = 0, RG = 0
FILTER = 0, RG = 15
FILTER = 15, RG = 0
FILTER = 15, RG = 15
0.4
0.6
1.1
5
0.8
1.2
2.2
10
ms
ms
ms
ms
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
24
48
100
200
32
64
132
264
µs
µs
µs
µs
Table 5: Timing Specifications
9 Accuracy
DC operating parameters at V
DD
= 5V (unless otherwise specified) and for T
A
as specified by the temperature
range (E or L).
Parameter Symbol
††
Test Conditions Min Typical
Max Units
T
V
OQ
V
OQ
= 2.5V
(1)
,
25
°C
/ 150
°C
V
OQ
= 2.5V
(1)
, 25°C / -40°C
-
0.2
- 0.4
+ 0.2
+ 0.4
%
V
DD
%V
DD
Life Time Drift of the Thermal
Voq Drift
L
T
V
OQ
-
0.2
+ 0.2
%
V
DD
Life Time Voq Drift
L
V
OQ
-
0.3
+ 0.3
%
V
DD
Life Time Sensitivity Drift
L
S
-
1
+ 1
%
Sensitivity Temperature
Coefficient
TCs
0 to 500
ppm /
°C
500 to 1200 ppm / °C
1200 to 2300 ppm / °C
±
100
± 150
± 200
ppm /
°C
ppm / °C
ppm / °C
Thermal Drift of Sen
sitivity
Temperature Compensation
T
TC
VA
-
package
GO-package
150
250
ppm /
°C
Thermal Drift Output Clamping
Levels
T
V
OUTCLAMP
-
0.4
+ 0.4
%
V
DD
Life Time Drift Output Clamping
Levels
L
V
OUTCLAMP
-
0.2
+ 0.2
%
V
DD
Linearity error
Le
0.2
%
Table 6: Accuracy Specifications
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 7 of 19 Data Sheet
Rev 010 Oct/11
Valid for Rough Gain within the specified option code.
††
L
= Life Time Drift (based on HTOL data [1000 hours @ 15C]).
T
= Thermal Drift.
(1)
For other test conditions, please contact the Melexis Sales representative of your area.
10 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
Internal Bias Point AGND Coarse adjustment of V
OQ
. 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 V
OQ
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. Preset
Melexis Lock
MLX_LOCK Used to lock Melexis area of the EEPROM. 1 0
Output Driver
MODE Adjustment for output stage amplifier. 2 1
Offset DAC OFFSET Fine adjustment of V
OQ
. 10 0
Oscillator Adjust
OSCADJ Chip oscillator frequency adjustment. 4 Preset
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
2nd Order Temperature
Compensations
TC
2
Linearization adjustment of the Sensitivity
Temperature Compensation.
6 0
Table 7: Programmable Parameters
Melexis parameter adjusted at final test.
††
Not included in redundant area of the EEPROM.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 8 of 19 Data Sheet
Rev 010 Oct/11
10.1 Output Quiescent Voltage (V
OQ
)
Two parameters, AGND and OFFSET, are used for adjustment of the V
OQ
. The AGND is a 10 bit parameter
for coarse adjustment of V
OQ
. It has a resolution of approximately 0.014V and a range of -100%V
DD
to
200%V
DD
. The OFFSET is a 10 bit parameter with a resolution of approximately -0.005V. The OFFSET
parameter is used for fine adjustment of the V
OQ
, 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
V
OQ
.
VV
OQ
DD
OFFSET
V
AGND
V
VV
00.5
1023
0.5
1023
25.14
75.0
=
+
+=
This formula approximates the typical V
OQ
of the MLX90251. The actual V
OQ
formula varies slightly from chip
to chip. Melexis calibrates the AGND setting during final test so that the V
OQ
is approximately 50%V
DD
with
OFFSET set to 512. This gives the V
OQ
a range of 0%V
DD
to 100%V
DD
without adjusting the AGND value.
The OFFSET parameter is often used to set the offset in the application's output transfer characteristic.
10.2 Thermal V
OQ
Drift (DRIFT)
The Thermal V
OQ
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 V
OQ
accuracy below 10mV over a temperature span of 25°C to
150°C. This parameter is not used by the end customer.
10.3 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) 16 1.0 16
01 (00 01) 16 1.5 24
02 (00 10) 16 2.33 37
03 (00 11) 16 4.0 64
04 (01 00) 39 1.0 39
05 (01 01) 39 1.5 59
06 (01 10) 39 2.33 91
07 (01 11) 39 4.0 156
08 (10 00) 82 1.0 82
09 (10 01) 82 1.5 123
10 (10 10) 82 2.33 191
11 (10 11) 82 4.0 328
12 (11 00) 205 1.0 205
13 (11 01) 205 1.5 308
14 (11 10) 205 2.33 477
15 (11 11) 205 4.0 820
Table 8: MLX90251 Rough Gain Small Signal Amplifier Gain
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 9 of 19 Data Sheet
Rev 010 Oct/11
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:
1023
*6.01
1
FG
GainFine
=
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 a South magnetic field. A value of 1
makes the Sensitivity negative and the output voltage decreases in response to a South magnetic field.
Refer to section 10.5, Sensitivity Polarity, for more information on INVERT.
10.4 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 Sensitivity Range
(mV/mT)
Typical Magnetic Field Range
(mT, B
MAX
- B
MIN
)
0 0-3 (00 xx) 2.6 < S < 15 333 < B < 800
1 4-7 (01 xx) 10 < S < 35 156 < B < 333
2 8-11 (10 xx) 18 < S < 90 62 < B < 156
3 12-15 (11 xx) 50 < S < 210 6 < B < 62
Table 9: Optimized Sensitivity Range
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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 10 of 19 Data Sheet
Rev 010 Oct/11
Figures 10.4-1…10.4-4 Sensitivity versus RG and FG
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 11 of 19 Data Sheet
Rev 010 Oct/11
10.5 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 as a South magnetic field is applied and decreases in the presence of a 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.
10.6 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% V
DD
.
VV
VV
DD
DD
CLAMPHIGH
V
ClampHi
CLAMPLOW
V
ClampLo
00.5
00.5
1023
10.5
1023
10.5
=
=
=
=
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).
FIELD
CLAMP HIGH
CLAMP LOW
VOUT
Linear Operating
Region
Transition Point
Figure 10.6 Output Voltage Clamping Deviation
DC operating parameters at V
DD
= 5V (unless otherwise specified) and for T
A
as specified by the temperature
range (E or L).
Parameter Symbol Test Conditions Min Typical
Max Units
Clamp Comparator Offset
CLAMP
OFF
-
0.7
+ 0.7
%
V
DD
Table 10: Clamp Comparator Offset Specification
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 12 of 19 Data Sheet
Rev 010 Oct/11
10.7 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 MLX90251-0
Rough Gain 0…3
MLX90251-1
Rough Gain 4…7
MLX90251-2
Rough Gain 8…11
MLX90251-3
Rough Gain 12…15
0 22900 14300 7000 3850
1 19500 11450 5550 2950
2 12300 10000 3000 2300
3 10400 6750 2100 1100
4 7450 3900 1500 850
5 5850 2900 1125 860
6 5700 2700 1350 715
7 5050 2550 1380 650
8 Not used
9 Not used
10 Not used
11 Not used
12 2200 840 565 250
13 1000 480 470 190
14 920 380 290 155
15 800 330 250 135
Table 11: Cut-off Frequency versus FILTER and RG Parameters
10.8 Sensitivity Temperature Compensation (TC, TCW, TC
2
)
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, TC
2
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 TC
2
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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 13 of 19 Data Sheet
Rev 010 Oct/11
TempCo Range (ppm / °C) Accuracy (ppm / °C)
0 to 500 ± 100
500 to 1200 ± 150
1200 to 2000 ± 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 10.4 for information on selecting the option code.
10.9 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 V
DD
(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.
10.10 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 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.
10.11 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.
10.12 Memory Lock (MEMLOCK)
The Memory Lock feature prevents the device from entering programming mode and from any changes to the
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 14 of 19 Data Sheet
Rev 010 Oct/11
EEPROM. The entire EEPROM is locked by setting the MEMLOCK parameter to 1. This should be the last
parameter set in the application.
10.13 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.
11 Performance Graphs
Figure 11-1…11-2 I
DD
Versus V
DD
-10 0 10 20 30
-80
-60
-40
-20
0
20
40
60
Typical I
DD
VS V
DD
V
DD
(Volts)
I
DD
(mA)
4 4.5 5 5.5 6
4.5
5
5.5
6
6.5
7
7.5
8
8.5
Typical I
DD
VS V
DDNOM
V
DD
(Volts)
I
DD
(mA)
150
°
C
-40
°
C
25
°
C
150
°
C
-40
°
C
25
°
C
V
DDNOM
Over Voltage
Under Voltage
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 15 of 19 Data Sheet
Rev 010 Oct/11
12 Applications Information
12.1 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.
Figures 12.1-1…12.1-2 Application Circuits
A voltage of 9V is required on V
DD
for programming. All additional components connected to V
DD
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.
12.2 Programming the Sensor
To program the MLX90251 connection to V
DD
, GND, and V
OUT
is required. The device is placed into program
mode by increasing the supply voltage to the V
DD
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.
Figure 12.2-1 V
DD
Programming Level Figure 12.2-2 Tri-Level PTC
0V
2.5V
5.0V
Device
Decoded
Clock
Device
Decoded
Data
0
1
X XX
VOUT
Program Wave Form
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 16 of 19 Data Sheet
Rev 010 Oct/11
Note: External capacitors and resistors will effect the rise and fall times for the programming waveforms.
Program pulse timings may require adjustment for the application. The device can not 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.
12.3 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.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 17 of 19 Data Sheet
Rev 010 Oct/11
13 Standard information regarding manufacturability of Melexis
products with different soldering processes
Our products are classified and qualified regarding soldering technology, solderability and moisture sensitivity
level according to following test methods:
Reflow Soldering SMD’s (Surface Mount Devices)
IPC/JEDEC J-STD-020
Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices
(classification reflow profiles according to table 5-2)
EIA/JEDEC JESD22-A113
Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing
(reflow profiles according to table 2)
Wave Soldering SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
EN60749-20
Resistance of plastic- encapsulated SMD’s to combined effect of moisture and soldering heat
EIA/JEDEC JESD22-B106 and EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Iron Soldering THD’s (Through Hole Devices)
EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Solderability SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
EIA/JEDEC JESD22-B102 and EN60749-21
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.
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/quality.asp
14 ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 18 of 19 Data Sheet
Rev 010 Oct/11
15 Package Information
VA-package: the lead-free VA-package is released for MSL1/245°C.
15.1 VA Package Outline and Hall Plate Position
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 19 of 19 Data Sheet
Rev 010 Oct/11
16 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.
© 2011 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, Africa, Asia: America:
Phone: +32 1367 0495 Phone: +1 603 223 2362
E-mail: sales_europe@melexis.com E-mail: sales_usa@melexis.com
ISO/TS 16949 and ISO14001 Certified
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 20 of 19 Data Sheet
Rev 010 Oct/11
This page not intended for distribution or distilling
Rev.
Date
By
Change
002 22 Sep 03 PTE
All parts changed
Main changes:
- remove the Melexis parameters.
- AGND parameter move from Melexis to Customer Parameter
002 29 Sep 03 PTE
- Date code: YYWW (instead of WWYY)
- In table page 4: Ohm in a correct police to be printed correctly in pdf
format
- In table page 6: Delta in a correct police to be printed correctly in
pdf format
002 15 Oct 03 PTE
Update of the Default settings
Add in Features: -100%Vdd…+200%Vdd Voq Range
Text in 9.1 and 9.2
In Accuracy table: added Life Time Sensitivity Drift spec.
002 17 Nov 03 PTE
- Change of the VA drawing
- Change of sensitivity
min: 2.6 (instead of 3.5 mV/mT)
max: 210 (instead of 280 mV/mT)
002 24 Nov 03 PTE - Temperature code E (instead of K)
- Page 2: all text in Arial police
002 7 Jan 04 PTE
- Page 4:
removed Vdd spec (4.0V 6.0V) for reduced accuracy
removed Idd spec for Vdd=4.0V 6.0V
003 21 Jul 04 PTE
Change the ordering informations.
Change the layout to put all data on page 1.
Change of the RG parameter explanation.
Change of the FG parameter explanation.
Added sensitivity vs RG and FG chapter.
Change of the Filter explanation.
Reability information updated.
"ISO/TS16949 and ISO14001 Certified" added.
Glossary of terms: DTS and DIDO added.
Maximun Supply Voltage, added: V/dt < 1V/µs
004 21 Sept 04 JLP
Updated layout to latest template
Added Overvoltage slew rate spec in Absolute max ratings
Added Section 5
Added Power on Reset and Over voltage detection spec Table 2
Added Output current spec Table 2
Added Table 6 Programmable features
Updated description of the programmable features section 10
Removed MODE Table
Modified Sensitivity graphs figures 10.4-1..4
Added Section 11
Added Section 12.1, 12.2, and 12.3
005 19 May 05 JLP
Added GO package to ordering info.
Change ordering info layout.
Added pin out on page 1.
Fixed various grammer and typographical errors.
Added Column to Table 6 (Default settings)
Added Section 12.2 Output Diagnostic
Added Sections 15.2-15.4 (GO package detail)
005 25 May 05 PHI Adapt datasheet according to the 90251FA version
Change GO package drawings
MLX90251
Programmable Linear Hall Effect Sensor
3901090251 Page 21 of 19 Data Sheet
Rev 010 Oct/11
Add comments
008 2 Nov 05 PHI
Remove comments.
Update “Reliability Information”: remove paragraph of lead-free
roadmap + use new template
Adapt GO package info.
Add info about lead-free to “Package Information”.
Add lead-free to “Features and Benefits”.
Add new spec of thermal TC drift for GO-package
009 21 Feb 06 Phi
Adapt spec of maximum rating of Idd_rev to -85mA.
Add test condition “Voq = 2.5V” for the Thermal Voq Drift
specification and the comment “For other Test conditions, please
contact the Melexis Sales Representative of your area”.
010 10 Oct 11 BBB
Remove all references to GO package (ordering information,
package drawings and descriptions, application diagrams, pinout) +
cosmetic changes for proper layout