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