MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending 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 E Functional Diagram 1 Temperature Range -40°C to 150°C -40°C to 85°C Description VDD 2 OTPROM (ROM) Package VA(4 Lead SIP) VA(4 Lead SIP) Shift Register (RAM) DAC DAC DAC Program Decoder 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. Hall Plate Chopper 3 Pin 1 Pin 2 Pin 3 Pin 4 4 - VDD (Supply) - Test/Readback Enable - VSS (Ground) - Output 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. MLX90215 Programmable Hall Effect Sensor Rev 4.3 7/6/01 Page 1 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending MLX90215 Electrical Specifications Parameter Symbol Test Conditions Min Typ Max Units B = 0, VDD = 5V, IOUT = 0 2.5 4.0 6.5 mA IOUT VDD = 5V + 10% -2 - 2 mA 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 Impulse Response Time (6) T RMIN RoughGain @ Min 25 - µs Impulse Response Time (6) T RMIN 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 -1.5 - 1.5 mV -20 - 20 mV -40 - 40 mV 5 - 140 mV/mT 8 25 60 mV Supply Voltage Supply Current Output Current (1) Quiescent Output Voltage (2) VDD Operating IDD ∆VOQ/∆T B = 0, TA = -40oC to 150oC S < 100mV/mT & VOQ > 0.75V ∆VOQ/∆T B = 0, TA = -40oC to 150oC S > 100mV/mT & VOQ < 0.75V s 13-Bit Programmable Peak to Peak Noise (4) Output Resistance 4.5 4 ROUT Sensitivity Drift(5) 5.0 5.5 V 0.35 0.50 V - 40 kHz - 1.300 kHz µs Ω 6 TA = 25 C -1 o V - 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 inversely proportional to ROUGHGAIN. (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 (∆V OQ or ∆V OQ/∆T). The tolerance for sensitivity is + 1% of its initial value. This does not include tolerance stack-up. (6) If the impulse occurs in the middle of a sample interval, the small signal response delay will double. If a 50% to 100% impulse, slew rate may result in double or triple delay. (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. MLX90215 Programmable Hall Effect Sensor Rev 4.3 7/6/01 Page 2 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending 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 31-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. HALFVDD function, the VOQ can be set to one of two 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 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 (VOQ) 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 MLX90215 Programmable Hall Effect Sensor Rev 4.3 7/6/01 Page 3 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending Temperature Compensation Temperature compensation (TC) is defined as the change in sensitivity over temperature. Expressed in (Parts Per Million per Degree Celcius) ppm/ o C. 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 25o C 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 Min -600 -535 -465 -390 -300 -235 -150 -85 125 125 210 285 450 535 600 680 1150 1230 1320 1405 1490 1575 1665 1750 2165 2340 2425 2500 2595 2680 2710 2775 Typical -450 -385 -315 -240 -150 -85 0 65 275 360 435 515 600 685 750 830 1300 1380 1470 1555 1640 1725 1815 1900 2365 2490 2575 2650 2745 2830 2910 2975 Max -300 -235 -165 -90 0 65 150 215 425 510 585 665 750 835 900 980 1450 1530 1620 1705 1790 1875 1965 2950 2565 2640 2725 2800 2895 2980 3110 3175 MLX90215 Programmable Hall Effect Sensor 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 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/ o C. The MLX90215 can be programmed with a TC of 300 ppm/ o C to counteract the TC of the magnet and greatly improve linearity over temperature. 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 second line brand showing “15DXX” Special Note The MLX90215 programmed with a zero TC code (default) has a typical TC value between the range of – 300 to –600 ppm/ o C. 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. Early revisions of the MLX90215 with second line brand of “15AXX” should refer to factory for Tc code 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% V DD VDD open with pull down load VOUT = VSS Rev 4.3 7/6/01 Page 4 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending 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 Flux Density (mT) Typical Peak to Peak Noise versus Sensitivity Typical Sample Rate versus Rough Gain (PA) MLX90215 60 MLX90215 40 -6 -12 -18 270 180 90 0 -90 -180 -270 Flux Density (mT) 50 Output Voltage (mV) Sample Rate (kHz) 32.7 25.4 18.1 10.8 3.5 40 30 20 10 0 7 RoughGain (PA) Value MLX90215 Programmable Hall Effect Sensor 140 6 115 5 90 4 65 3 40 2 15 1 5 0 Sensitivity (mV/mT) Rev 4.3 7/6/01 Page 5 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending Melexis Programmer Absolute Maximum Ratings Melexis offers a programmer (PTC-01) for progra mming 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. Supply Voltage (Over Voltage) Left, PTC-01 windows based software. Works with any IBM compatible PC running windows 9x. 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 +7kV . Melexis PTC-01 Programmer Pin Description Recommended Wiring MLX 90215 V DD 1 2 C1 Pin1 Pin2 Pin3 Pin4 V DD Test* V SS OUT 3 4 C2 C1 = 2.5nF C2 = 2.5nF Mutilayer surface mount capacitors recommended *Readback diagnostic use only. Pin 2 is NOT for programming device. For best results, tie to GND. MLX90215 Programmable Hall Effect Sensor Rev 4.3 7/6/01 Page 6 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending 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 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 is programmed at 1/2 VDD . This is with the 1/2 VDD 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/ o C. 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. Installation Comments 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 bend ing. 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. MLX90215 Programmable Hall Effect Sensor Rev 4.3 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 26 TEMP CO 0 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 7/6/01 Page 7 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending Physical Characteristics 5.33 5.43 VA Package Dimensions 5.08 5.24 VA Hall Plate / Chip Location 2.69 J 1.22 1.32 Hall Plate 0.20 x 0.20 3.76 3.86 4.50 4.10 2.86 45 o X 1mm C 5o (2x) 0014 * 15D88 2.18 5o (2x) 3.46 3.30 0.387 0.289 Marked Surface 3.79 3.63 D VA F G 1.0 MA X H 1 2 3 0.22 REF A 1.20 1.10 B 0.66 0.61 C 0.29 0.24 4 15.50 14.50 0.45 0.35 D 45 o E 0.31 0.18 F 0.60 0.40 G 0.35 0.25 H 0.15 0.0 J 45 o 0.387 0.289 1.86 A B All Dimensions in millimeters E Notes: 1. Pinout: Pin 1 VDD Pin 2 Test/Readback Pin 3 GND Pin 4 Output 2. Controlling dimension: mm . 3. Leads must be free of flash and plating voids. 4. Leads must not arc toward the rear of package. 5. VA lead frame material: C151. 6. VA molding compound: Sumitomo EME 6300H. 7. Package dimensions exclude molding flash. 8. Tolerance: +/- 0.254 mm unless otherwise specified. 9 . *Marking: Line 1: 1st and 2nd digits (00) = Year (2000) 3rd and 4th digits (14) = Week of Year Line 2: 1st and 2nd digits (15) 3rd digit (D) 4th and 5th digits(88) = Chip I.D. (90215) = Chip Revision = Lot Number For the latest version of this document, Go to our Website at: WWW.Melexis.Com For additional information Contact Melexis direct at: Europe and Japan E-mail: [email protected] Phone: 011-32-13-670-780 MLX90215 Programmable Hall Effect Sensor USA and Rest of World [email protected] (603) 223-2362 Rev 4.3 7/6/01 Page 8 MLX90215 Precision Programmable* Linear Hall Effect Sensor *Patent Pending Application Notes Linear Precision Current Sensor Programmable 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 flexib le design. VDD Slotted Torroid Example Assuming infinite perme abilty of the core, the magnetic field through the air gap produced by a single wire turn is given by equation 2 Equation 2 I u lg o 5 V OUT (Volts) B= A slotted ferrite toroidal core and a series of windings are the main elements of a current sensor. By adding a programmable Hall IC to the air gap, not only can the output be calibrated accurately, but it can also be adjusted to respond to virtually any range of current MLX 90215 Where: I = current in Amperes B = magnetic field in Tesla lg = length of air gap in Meters u o = Permeability of free space (4π10-7 H/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. 4 3 2 1 0 -100 0 100 Current (Amps) 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. MLX90215 Programmable Hall Effect Sensor Rev 4.3 7/6/01 Page 9