Data Sheet, Rev 1.1, September 2009 TLE4998S3C Programmable Linear Hall Sensor Sensors N e v e r s t o p t h i n k i n g . Edition 2009-09 Published by Infineon Technologies AG, Am Campeon 1-12, 85579 Neubiberg, Germany © Infineon Technologies AG 2009. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as a guarantee of characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. 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TLE4998S3C Revision History: 2009-09 Previous Version: Data Sheet Rev 1.0 Page Subjects (major changes since last revision) Page 12 Table 4: Footnote 3) adapted Page 14 Table 5: Sensitivity drift description adapted Page 14 Table 5: Footnote 3) adapted Page 24 Table 14: Footnote 1) and 2) adapted General Package nomenclature changed to PG-SSO-3-92 Rev 1.1 We Listen to Your Comments Any information within this document that you feel is wrong, unclear or missing at all? Your feedback will help us to continuously improve the quality of this document. Please send your proposal (including a reference to this document) to: [email protected] TLE4998S3C 1 1.1 1.2 1.3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Target Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5 6 6 2 2.1 2.2 2.3 2.4 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transfer Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7 7 8 9 3 Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4 Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5 Electrical, Thermal, and Magnetic Parameters . . . . . . . . . . . . . . . . . . . 12 Calculation of the Junction Temperature . . . . . . . . . . . . . . . . . . . . . . 14 Magnetic Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6 6.1 6.2 6.3 6.4 6.5 Signal Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnetic Field Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnetic Field Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gain Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Offset Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DSP Input Low-Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clamping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1 7.2 Error Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Voltages Outside the Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 EEPROM Error Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8 8.1 Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Parameter Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9 9.1 9.2 9.3 9.4 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calibration Data Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Programming Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data Transfer Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Programming of Sensors with Common Supply Lines . . . . . . . . . . . . . . . 10 Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 11 PG-SSO-3-92 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 12 12.1 12.2 12.3 SENT Output Definition (SAE J2716) . . . . . . . . . . . . . . . . . . . . . . . . . . . Basic SENT Protocol Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unit Time Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Checksum Nibble Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data Sheet 4 16 16 16 17 18 18 19 21 26 27 28 28 28 31 31 32 35 Rev 1.1, 2009-09 Programmable Linear Hall Sensor 1 Overview 1.1 Features TLE4998S3C • Single Edge Nibble Transmission (SENT) open-drain output signal (SAE J2716) • 20-bit Digital Signal Processing (DSP) • Digital temperature compensation • 16-bit overall resolution • Operates within automotive temperature range • Low drift of output signal over temperature and lifetime • Programmable parameters stored in EEPROM with single-bit error correction: – SENT unit time – Magnetic range and sensitivity (gain), polarity of the output slope – Offset – Bandwidth – Clamping levels – Customer temperature compensation coefficients – Memory lock • Re-programmable until memory lock • Supply voltage 4.5 - 5.5 V (4.1 - 16 V extended range) • Operation between -200 mT and +200 mT within three ranges • Reverse-polarity and overvoltage protection for all pins • Output short-circuit protection • On-board diagnostics (overvoltage, EEPROM error, start up) • Output of internal magnetic field values and temperature • Programming and operation of multiple sensors with common power supply • Two-point calibration of magnetic transfer function without iteration steps • High immunity against mechanical stress, EMC, ESD • Package with two capacitors: 47nF (VDD to GND) and 4.7nF (OUT to GND) PG-SSO-3-9x Type Marking Ordering Code Package TLE4998S3C 98S3C SP000481484 PG-SSO-3-92 Data Sheet 5 Rev 1.1, 2009-09 TLE4998S3C Overview 1.2 Target Applications • Robust replacement of potentiometers – No mechanical abrasion – Resistant to humidity, temperature, pollution and vibration • Linear and angular position sensing in automotive applications such as pedal position, suspension control, throttle position, headlight levelling, and steering torque sensing • Sensing of high current for battery management, motor control, and electronic fuses 1.3 Pin Configuration Figure 1 shows the location of the Hall element in the chip and the distance between Hall probe and the surface of the package. B 2.67 d 0.2 B A 1.53 Center of sensitive area Branded Side 2 Hall-Probe 3 0.2 A 1 d: Distance chip to upper side of IC 0.3 ±0.05 mm AEP03538 Figure 1 TLE4998x3C Pin Configuration and Hall Cell Location Table 1 TLE4998S3C Pin Definitions and Functions Pin No. Symbol Function 1 VDD Supply voltage / programming interface 2 GND Ground 3 OUT Output / programming interface Data Sheet 6 Rev 1.1, 2009-09 TLE4998S3C General 2 General 2.1 Block Diagram Figure 2 is a simplified block diagram. VDD Supply Bias *) EEPROM spinning HALL Interface TST A D OUT DSP Temp. Sense SENT A D GND ROM Figure 2 2.2 *) TLE4998S4 only Block Diagram Functional Description The linear Hall IC TLE4998S3C has been designed specifically to meet the requirements of highly accurate rotation and position detection, as well as for current measurement applications. Two capacitors are integrated on the lead frame, making this sensor especially suitable for applications with demanding EMC requirements. The sensor provides a digital SENT signal based on the SAE J2716 standard, which consists of a sequence of pulses. Each transmission has a constant number of nibbles containing the Hall value, the temperature, and status information of the sensor.The output stage is an open-drain driver pulling the output pin to low only. Therefore, the high level needs to be obtained by an external pull-up resistor. This output type has the advantage that the receiver may use an even lower supply voltage (e.g. 3.3 V). In this case the pull-up resistor must be connected to the given receiver supply. Data Sheet 7 Rev 1.1, 2009-09 TLE4998S3C General The IC is produced in BiCMOS technology with high voltage capability, and it also has reverse-polarity protection. Digital signal processing using a 16-bit DSP architecture together with digital temperature compensation guarantee excellent long-time stability compared to analog compensation methods. While the overall resolution is 16 bits, some internal stages work with resolutions up to 20 bits. 2.3 Principle of Operation • A magnetic flux is measured by a Hall-effect cell • The output signal from the Hall-effect cell is converted from analog to digital • The chopped Hall-effect cell and continuous-time A/D conversion ensure a very low and stable magnetic offset • A programmable low-pass filter to reduce noise • The temperature is measured and A/D converted, too • Temperature compensation is done digitally using a second-order function • Digital processing of output value is based on zero field and sensitivity value • The output value range can be clamped by digital limiters • The final output value is represented by the data nibbles of the SENT protocol Data Sheet 8 Rev 1.1, 2009-09 TLE4998S3C General 2.4 Transfer Functions The examples in Figure 3 show how different magnetic field ranges can be mapped to the desired output value ranges. • Polarity Mode: – Bipolar: Magnetic fields can be measured in both orientations. The limit points do not necessarily have to be symmetrical around the zero field point – Unipolar: Only north- or south-oriented magnetic fields are measured • Inversion: The gain can be set to both positive and negative values OUT12 / OUT16 B (mT) 50 4095 / 100 65535 0 0 -50 OUT12 / OUT16 B (mT) 4095 / 65535 0 0 -100 Example 1: - Bipolar Figure 3 Data Sheet B (mT) OUT12 / OUT16 200 4095 / 65535 0 0 -200 Example 2: - Unipolar - Big offset Example 3: - Bipolar - Inverted (neg. gain) Examples of Operation 9 Rev 1.1, 2009-09 TLE4998S3C Maximum Ratings 3 Maximum Ratings Table 2 Absolute Maximum Ratings Parameter Symbol Limit Values min. Storage temperature TST - 40 Unit Notes max. 150 °C 1) Junction temperature TJ - 40 170 °C Voltage on VDD pin with respect to ground VDD -18 18 V Supply current @ overvoltage VDD max. IDDov - 15 mA Reverse supply current @ VDD min. IDDrev -1 0 mA Voltage on output pin with VOUT respect to ground -13) 184) V Magnetic field BMAX - unlimited T ESD protection VESD - 8 kV 2) According HBM JESD22-A114-B 5) 1) For limited time of 96 h. Depends on customer temperature lifetime cycles. Please ask for support by Infineon 2) Higher voltage stress than absolute maximum rating, e.g. 150% in latch-up tests is not applicable. In such cases, Rseries ≥100 Ω for current limitation is required 3) IDD can exceed 10 mA when the voltage on OUT is pulled below -1 V (-5 V at room temperature) 4) VDD = 5 V, open drain permanent low, for max. 10 minutes 5) 100 pF and 1.5 kΩ Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Data Sheet 10 Rev 1.1, 2009-09 TLE4998S3C Operating Range 4 Operating Range The following operating conditions must not be exceeded in order to ensure correct operation of the TLE4998S3C. All parameters specified in the following sections refer to these operating conditions, unless otherwise indicated. Table 3 Operating Range Parameter Supply voltage Symbol Limit Values VDD min. max. 4.5 5.5 1) 2) Unit V 4.1 16 V Vpull-up - 18 V RL 1 - kΩ Output current3) IOUT 0 5 mA Junction temperature TJ - 40 125 1504) °C Output pull-up voltage3) Load resistance3) Notes Extended range For 5000 h For 1000 h not additive 1) For reduced output accuracy 2) For supply voltages > 12 V, a series resistance Rseries ≥ 100 Ω is recommended 3) Output protocol characteristics depend on these parameters, RL must be according to max. output current 4) For reduced magnetic accuracy; extended limits are taken for characteristics Keeping signal levels within the limits specified in this table ensures operation without overload conditions. Data Sheet 11 Rev 1.1, 2009-09 TLE4998S3C Electrical, Thermal, and Magnetic Parameters 5 Electrical, Thermal, and Magnetic Parameters Table 4 Electrical Characteristics Parameter Symbol Limit Values Unit Notes min. typ. max. VDD-GND capacitor CVDD - 47 - nF Ceramic OUT-GND capacitor CL - 4.7 - nF Ceramic SENT transmission time tSENT - - 1 ms 1) Supply current IDD 3 6 8 mA Output current @ OUT shorted to supply lines IOUTsh - 95 - mA Thermal resistance RthJA - 190 - K/W Junction to air RthJC - 41 - K/W Junction to case Power-on time2) tPon - 0.7 15 2 20 ms Power-on reset level VDDpon - 3.6 4 V Output impedance ZOUT 19 30 44 kΩ 3) Output fall time tfall 2 - 4 µs VOUT 4.5 V to 0.5 V 4) Output rise time trise - 20 - µs VOUT 0.5 V to 4.5 V 4)5) Output low saturation voltage VOUTsat - 0.3 0.2 0.6 0.4 V IOUTsink = 5 mA IOUTsink = 2.2 mA Output noise (rms) OUTnoise - 1 2.5 LSB12 6) VOUT = 5 V, max. 10 minutes ≤ ± 5% target out value ≤ ± 1% target out value 1) Transmission time depends on the data values being sent and on int. RC oscillator freq. variation of +/- 20% 2) Response time to set up output data at power on when a constant field is applied. The first value given has a ± 5% error, the second value has a ± 1% error. Measured with 640-Hz low-pass filter 3) Output impedance is measured ∆VOUT/∆IOUT (∆VOUT=18V ... 4.2V) at VDD = 5V, open-drain high state 4) For VDD = 5 V, RL = 2.2 kΩ, CL = 4.7 nF (in package), at room temperature, not considering condensator tolerance or influence of external circuitry Data Sheet 12 Rev 1.1, 2009-09 TLE4998S3C Electrical, Thermal, and Magnetic Parameters 5) Depends on external RL and CL VOUT *) t HIGH tlow VDD 90% VDD 10% VDD VOUTsat *) RL to VDD assumed tfall 6) trise t Range 100 mT, Gain 2.23, internal LP filter 244 Hz, B = 0 mT, T = 25 °C Data Sheet 13 Rev 1.1, 2009-09 TLE4998S3C Electrical, Thermal, and Magnetic Parameters Calculation of the Junction Temperature The internal power dissipation PTOT of the sensor increases the chip junction temperature above the ambient temperature. The power multiplied by the total thermal resistance RthJA (Junction to Ambient) added to TA leads to the final junction temperature. RthJA is the sum of the addition of the two components, Junction to Case and Case to Ambient. RthJA = RthJC + RthCA TJ = TA + ∆T ∆T = RthJA x PTOT = RthJA x ( VDD x IDD + VOUT x IOUT ) IDD , IOUT > 0, if direction is into IC Example (assuming no load on Vout): – VDD = 5 V – IDD = 8 mA – ∆T = 190 [K/W] x (5 [V] x 0.008 [A] + 0 [VA] ) = 7.6 K For moulded sensors, the calculation with RthJC is more adequate. Magnetic Parameters Table 5 Magnetic Characteristics Parameter Symbol Limit Values Unit min. typ. max. Notes Sensitivity S1) ± 8.2 - ± 245 LSB12/ Programmable2) mT Sensitivity drift ∆S - ± 80 ± 150 ppm/ °C 3) See Figure 4 Magnetic field range MFR ± 50 ± 1004) ± 200 mT Programmable 5) Integral nonlinearity INL - ± 0.05 ± 0.1 6)8) Magnetic offset BOS - - ± 400 µT Magnetic offset drift ∆BOS - ±1 ±5 µT / °C Error band8) Magnetic hysteresis BHYS - - 10 µT %MFR 7)8) 9) 1) Defined as ∆OUT / ∆B 2) Programmable in steps of 0.024% 3) For any 1st and 2nd order polynomial, coefficient within definition in Chapter 8. Valid for characterization at 0h Data Sheet 14 Rev 1.1, 2009-09 TLE4998S3C Electrical, Thermal, and Magnetic Parameters 4) This range is also used for temperature and offset pre-calibration of the IC 5) Depending on offset and gain settings, the output may already be saturated at lower fields 6) Gain setup is 1.0 7) In operating temperature range and over lifetime 8) Measured at ± 100 mT range 9) Measured in 100 mT range, Gain = 1, room temperature ∆S ~ S(T)/S0-1 max. pos. TC-error TCmax = ∆S/∆T ∆S0 0 Tmin Tmax T0 Tj max. neg. TC-error TCmin = ∆S/∆T Figure 4 Data Sheet Sensitivity drift 15 Rev 1.1, 2009-09 TLE4998S3C Signal Processing 6 Signal Processing The signal flow diagram in Figure 5 shows the signal path and data-processing algorithm. Range Gain LP Limiter (Clamp) Hall Sensor Temperature Sensor A D X D + Protocol Generation out Offset TC 2 X X A X 1 + TC 1 -T0 Stored in EEPROM Memory + X Temperature Compensation Figure 5 Signal Processing Flow Magnetic Field Path • The analog output signal of the chopped Hall-effect cell is converted to a digital signal in the continuous-time A/D converter. The range of the chopped A/D converter can be set in several steps (see Table 6). This gives a suitable level for the A/D converter • After the A/D conversion, a digital low-pass filter reduces the bandwidth (Table 10) • A multiplier amplifies the value depending on the gain (see Table 8) and temperature compensation settings • The offset value is added (see Table 9) • A limiter reduces the resulting signal to 16 bits (see Chapter 11) and feeds the Protocol Generation stage Temperature Compensation (Details are listed in Chapter 8) • The output signal of the temperature cell is also A/D converted Data Sheet 16 Rev 1.1, 2009-09 TLE4998S3C Signal Processing • The temperature is normalized by subtraction of the reference temperature T0 value (zero point of the quadratic function) • The linear path is multiplied with the TC1 value • In the quadratic path, the temperature difference to T0 is squared and multiplied with the TC2 value • Both path outputs are added together and multiplied with the Gain value from the EEPROM 6.1 Magnetic Field Ranges The working range of the magnetic field defines the input range of the A/D converter. It is always symmetrical around the zero field point. Any two points in the magnetic field range can be selected to be the end points of the output value. The output value is represented within the range between the two points. In the case of fields higher than the range values, the output signal may be distorted. The range must be set before the calibration of offset and gain. Table 6 Range Setting Range Range in mT1) Parameter R Low ± 50 3 Mid ± 100 12) High ± 200 0 1) Ranges do not have a guaranteed absolute accuracy. The temperature pre-calibration is performed in the mid range (100 mT) 2) Setting R = 2 is not used, internally changed to R = 1 Table 7 Parameter Range Symbol Limit Values min. Register size Data Sheet R Unit Notes max. 2 17 bit Rev 1.1, 2009-09 TLE4998S3C Signal Processing 6.2 Gain Setting The overall sensitivity is defined by the range and the gain setting. The output of the ADC is multiplied with the Gain value. Table 8 Gain Parameter Symbol Limit Values min. Register size Gain range - 4.0 Gain Gain quantization steps ∆Gain Notes bit Unsigned integer value - 1)2) ppm Corresponds to 1/4096 max. 15 G Unit 3.9998 244.14 1) For Gain values between - 0.5 and + 0.5, the numerical accuracy decreases To obtain a flatter output curve, it is advisable to select a higher range setting 2) A gain value of +1.0 corresponds to typical 32 LSB12/mT sensitivity (100 mT range, not guaranteed). It is crucial to do a final calibration of each IC within the application using the Gain/OUTOS value The Gain value can be calculated by: : ( G – 16384 ) Gain = -----------------------------4096 6.3 Offset Setting The offset value corresponds to an output value with zero field at the sensor. Table 9 Offset Parameter Symbol Limit Values min. Register size Offset range Offset quantization steps 1) Unit Notes bit Unsigned integer value LSB12 1) max. 15 OS OUTOS -16384 16383 ∆OUTOS 1 LSB12 Infineon pre-calibrates the samples at zero field to 50% output value (100 mT range), but does not guarantee the value. Therefore it is crucial to do a final calibration of each IC within the application The offset value can be calculated by: OUT OS = OS – 16384 Data Sheet 18 Rev 1.1, 2009-09 TLE4998S3C Signal Processing 6.4 DSP Input Low-Pass Filter A digital low-pass filter is placed between the Hall A/D converter and the DSP, and can be used to reduce the noise level. The low-pass filter has a constant DC amplification of 0 dB (Gain of 1), which means that its setting has no influence on the internal Hall ADC value. The bandwidth can be set to any of 8 values. Table 10 Low Pass Filter Setting Cutoff frequency in Hz (-3dB point)1) Note: Parameter LP 0 80 1 240 2 440 3 640 4 860 5 1100 6 1390 7 off 1) As this is a digital filter running with an RC-based oscillator, the cutoff frequency may vary within ±20% Table 11 Low-Pass Filter Parameter Symbol Limit Values min. Register size Corner frequency variation LP ∆f - 20 Unit Notes max. 3 bit + 20 % Note: In range 7 (filter off), the output noise increases. Data Sheet 19 Rev 1.1, 2009-09 TLE4998S3C Signal Processing Figure 6 shows the filter characteristics as a magnitude plot (the highest setting is marked). The “off” position would be a flat 0 dB line. The update rate after the low-pass filter is 16 kHz. 0 Magnitude (dB) -1 -2 -3 -4 -5 -6 101 2 10 10 3 Frequency (Hz) Figure 6 Data Sheet DSP Input Filter (Magnitude Plot) 20 Rev 1.1, 2009-09 TLE4998S3C Signal Processing 6.5 Clamping The clamping function is useful for separating the output range into an operating range and error ranges. If the magnetic field is exceeding the selected measurement range, the output value OUT is limited to the clamping values. Any value in the error range is interpreted as an error by the sensor counterpart. Table 12 Clamping Parameter Symbol Limit Values min. Register size Clamping value low Clamping value high Clamping quantization steps CL,CH OUTCL OUTCH ∆OUTCx Unit Notes bit (0...127) max. 2x7 0 65024 LSB16 1) 511 65535 LSB16 1) 2) LSB16 3) 512 1) For CL = 0 and CH = 127, the clamping function is disabled 2) OUTCL < OUTCH mandatory 3) Quantization starts for CL at 0 LSB16 and for CH at 65535 LSB16 The clamping values are calculated by: Clamping value low (deactivated if CL=0): OUT CL = CL ⋅ 32 ⋅ 16 Clamping value high (deactivated if CH=127): OUT CH = ( CH + 1 ) ⋅ 32 ⋅ 16 – 1 Data Sheet 21 Rev 1.1, 2009-09 TLE4998S3C Signal Processing Figure 7 shows an example in which the magnetic field range between Bmin and Bmax is mapped to output values between 10240 LSB16 and 55295 LSB16. OUT (LSB16) 65535 Error range OUTCH 55295 Operating range OUTCL 10240 Error range 0 Bmax Bmin B (mT) Figure 7 Clamping Example Note: The clamping high value must be above the low value. Data Sheet 22 Rev 1.1, 2009-09 TLE4998S3C Error Detection 7 Error Detection Different error cases can be detected by the On-Board Diagnostics (OBD) and reported to the microcontroller in the status nibble (see Chapter 11). 7.1 Voltages Outside the Operating Range The output signals an error condition if VDD crosses the overvoltage threshold level. Table 13 Overvoltage Parameter Symbol Limit Values min. Overvoltage threshold 1) VDDov typ. 16.65 17.5 Unit Notes max. 18.35 V 1) Overvoltage bit activated in status nibble, output stays in “off” state (high ohmic) 7.2 EEPROM Error Correction The parity method is able to correct a single bit in the EEPROM line. One other single bit error in another EEPROM line can also be detected, but not corrected. In an uncorrectable EEPROM failure, the open drain stage is disabled and kept in the off state permanently (high ohmic/sensor defect). Data Sheet 23 Rev 1.1, 2009-09 TLE4998S3C Temperature Compensation 8 Temperature Compensation The magnetic field strength of a magnet depends on the temperature. This material constant is specific for the different magnet types. Therefore, the TLE4998S3C offers a second-order temperature compensation polynomial, by which the Hall signal output is multiplied in the DSP. There are three parameters for the compensation: • Reference temperature T0 • A linear part (1st order) TC1 • A quadratic part (2nd order) TC2 The following formula describes the sensitivity dependent on the temperature in relation to the sensitivity at the reference temperature T0: S TC ( T ) = 1 + TC 1 × ( T – T 0 ) + TC 2 × ( T – T0 ) 2 For more information, please refer to the signal processing flow in Figure 5. The full temperature compensation of the complete system is done in two steps: 1. Pre-calibration in the Infineon final test The parameters TC1, TC2, T0 are set to maximally flat temperature characteristics with respect to the Hall probe and internal analog processing parts. 2. Overall system calibration The typical coefficients TC1, TC2, T0 of the magnetic circuitry are programmed. This can be done deterministically, as the algorithm of the DSP is fully reproducible. The final setting of the TC1, TC2, T0 values depend on the pre-calibrated values. Table 14 Temperature Compensation Parameter Register size TC1 1st order coefficient TC1 Quantization steps of TC1 Register size TC2 2nd order coefficient TC2 Quantization steps of TC2 Reference temp. Quantization steps of T0 Symbol Limit Values Unit Notes min. max. TL TC1 qTC1 - 9 TQ TC2 qTC2 T0 qT0 - 8 bit Unsigned integer values -4 4 ppm/ °C² 2) bit Unsigned integer values -1000 2500 ppm/ °C 1) 15.26 ppm/ °C 0.119 - 48 64 1 ppm/ °C² °C °C 3) 1) Relative range to Infineon TC1 temperature pre-calibration, the maximum adjustable range is limited by the register-size and depends on specific pre-calibrated TL setting, full adjustable range: -2441 to +5355 ppm/°C 2) Relative range to Infineon TC2 temperature pre-calibration, the maximum adjustable range is limited by the register-size and depends on specific pre-calibrated TQ setting, full adjustable range: -15 to +15 ppm/°C2 Data Sheet 24 Rev 1.1, 2009-09 TLE4998S3C Temperature Compensation 3) Handled by algorithm only (see Application Note) 8.1 Parameter Calculation The parameters TC1 and TC2 may be calculated by: TL – 160 TC 1 = ---------------------- × 1000000 65536 TQ – 128 TC 2 = ----------------------- × 1000000 8388608 Now the digital output for a given field BIN at a specific temperature can be calculated by: B IN - × S TC × S TCHall × S 0 × 4096 + OUT OS OUT = 2 ⋅ ----------- B FSR BFSR is the full-range magnetic field. It is dependent on the range setting (e.g 100 mT). S0 is the nominal sensitivity of the Hall probe times the Gain factor set in the EEPROM. STC is the temperature-dependent sensitivity factor calculated by the DSP. STCHall is the temperature behavior of the Hall probe. The pre-calibration at Infineon is performed such that the following condition is met: S TC ( T J – T 0 ) × S TCHall ( T J ) ≈ 1 Within the application, an additional factor BIN(T) / BIN(T0) is given due to the magnetic system. STC then needs to be modified to STCnew so that the following condition is satisfied: B IN ( T ) -------------------× S TCnew ( T ) × S TCHall ( T ) ≈ S TC ( T ) × S TCHall ( T ) ≈ 1 B IN ( T 0 ) Therefore, the new sensitivity parameters STCnew can be calculated from the precalibrated setup STC using the relationship: B IN ( T ) -------------------× S TCnew ( T ) ≈ S TC ( T ) B IN ( T 0 ) Data Sheet 25 Rev 1.1, 2009-09 TLE4998S3C Calibration 9 Calibration For the calibration of the sensor, a special hardware interface to a PC is required. All calibration and setting bits can be temporarily written into a Random Access Memory (RAM). This allows the EEPROM to remain untouched during the entire calibration process, since the number of the EEPROM programming cycles is limited. Therefore, this temporary setup (using the RAM only) does not stress the EEPROM. The digital signal processing is completely deterministic. This allows a two-point calibration to be performed in one step without iterations. After measuring the Hall output signal for the two end points, the signal processing parameters Gain and Offset can be calculated. Table 15 Calibration Characteristics Parameter Symbol 1) Unit Notes min. max. 10 30 °C ∆OUTCAL1 -8 8 LSB12 Position 1 ∆OUTCAL2 -8 8 LSB12 Position 2 Ambient temperature at TCAL calibration 2 point Calibration accuracy1) Limit Values Corresponds to ± 0.2% accuracy in each position Data Sheet 26 Rev 1.1, 2009-09 TLE4998S3C Calibration 9.1 Calibration Data Memory When the MEMLOCK bits are programmed (two redundant bits), the memory content is frozen and may no longer be changed. Furthermore, the programming interface is locked out and the chip remains in application mode only, preventing accidental programming due to environmental influences. Row Parity Bits Column Parity Bits User-Calibration Bits Pre-Calibration Bits Figure 8 EEPROM Map A matrix parity architecture allows automatic correction of any single-bit error. Each row is protected by a row parity bit. The sum of bits set (including this bit) must be an odd number (ODD PARITY). Each column is additionally protected by a column parity bit. Each bit in the even positions (0, 2, etc.) of all lines must sum up to an even number (EVEN PARITY), and each bit in the odd positions (1, 3, etc.) must have an odd sum (ODD PARITY). The parity column must have an even sum (EVEN PARITY). This system of different parity calculations also protects against many block errors (such as erasing a full line or even the whole EEPROM). When modifying the application bits (such as Gain, Offset, TC, etc.), the parity bits must be updated. As for the column bits, the pre-calibration area must be read out and considered for correct parity generation as well. Note: A specific programming algorithm must be followed to ensure data retention. A detailed separate programming specification is available on request. Data Sheet 27 Rev 1.1, 2009-09 TLE4998S3C Calibration Table 16 Programming Characteristics Parameter Symbol Limit Values Number of EEPROM programming cycles NPRG Ambient temperature at TPRG programming Unit Notes min. max. - 10 Cycles1) Programming allowed only at start of lifetime 10 30 °C 100 - ms For complete memory 2) Programming time tPRG Calibration memory - 150 Bit All active EEPROM bits Error Correction - 26 Bit All parity EEPROM bits 1) 1 cycle is the simultaneous change of ≥ 1 bit 2) Depending on clock frequency at VDD, write pulse 10 ms ±1%, erase pulse 80 ms ±1% 9.2 Programming Interface The VDD pin and the OUT pin are used as a two-wire interface to transmit the EEPROM data to and from the sensor. This allows: • Communication with high data reliability, parity protected • The bus-type connection of several sensors and separate programming via the OUT pin 9.3 Data Transfer Protocol The data transfer protocol is described in a separate document (User Programming Description), available on request. 9.4 Programming of Sensors with Common Supply Lines In many automotive applications, two sensors are used to measure the same parameter. This redundancy makes it possible to continue operation in an emergency mode. If both sensors use the same power supply lines, they can be programmed together in parallel. Data Sheet 28 Rev 1.1, 2009-09 TLE4998S3C Application Circuit 10 Application Circuit Figure 9 shows the connection of multiple sensors to a microcontroller. Sensor Module Voltage Supply Sensor Voltage Supply µC ECU Module µC VDD Vdd VDD TLE out 4998x3C 2k2 OUT1 50 CCin1 GND 1n GND VGND CCin2 2k2 V DD TLE out 4998x3C OUT2 50 GND Figure 9 optional 1n Application Circuit Note: For calibration and programming, the interface has to be connected directly to the OUT pin. The application circuit shown should be regarded as an example only. It will need to be adapted to meet the requirements of other specific applications. Data Sheet 29 Rev 1.1, 2009-09 TLE4998S3C PG-SSO-3-92 Package Outlines PG-SSO-3-92 Package Outlines 5.34 ±0.05 5.16 ±0.08 B 1 x 45˚ ±1˚ 0.2 2A 1.905 B 0.25 ±0.05 C 7˚ ±2˚ A C 2.2 ±0.05 A 0.1 0.2 +0.04 0.35 ±0.05 (8.17) 0.87±0.05 5.67±0.1 1.67±0.05 7.07±0.1 0.6 MAX. 1.9 MAX. 0.4 ±0.05 1 MAX.1) 0.2 B (2.68) 2x 0.2 B (2.2) 0.65 ±0.1 (0.25) 7˚ B 1-0.1 7˚ 1.905 3.38 ±0.06 0.1 MAX. 1.9 MAX. 3.71±0.08 11 5.34 ±0.05 5.16 ±0.08 0.9 ±0.05 1 1.655 2 0.2 B 1.2 ±0.05 0.2 B 3x 3 2 x 1.655 = 3.31 7˚ (0.52) Capacitor (1.75) 45˚ ±1˚ (1.75) C-C (4.35) Burr MAX 0.15 5.16 ±0.08 Burr MAX 0.15 Burr MAX 1.1 B 0.2 1-1 6 ±0.5 18 ±0.5 9 +0.75 -0.5 38 MAX. 2 C (14.8) (Useable Length) 23.8 ±0.5 12.7 ±1 Burr MAX 1.1 (0.9) B-B 15˚ ±2˚ (1.75) A-A A Adhesive Tape Tape 6.35 ±0.4 4 ±0.3 12.7 ±0.3 Total tolerance at 10 pitches ±1 1) No solder function area Figure 10 Data Sheet 0.25 -0.15 0.39 ±0.1 P/PG-SSO-3-9x-PO V07 PG-SSO-3-92 (Plastic Green Single Small Outline Package) 30 Rev 1.1, 2009-09 TLE4998S3C SENT Output Definition (SAE J2716) 12 SENT Output Definition (SAE J2716) The sensor supports a basic version of the Single Edge Nibble Transmission (SENT) protocol defined by SAE. The main difference between the standard version and its implementation in the TLE4998 is the usage of an open drain instead of a push-pull output. 12.1 Basic SENT Protocol Definition The single edge is defined by a 3 unit time (UT) low pulse on the output, followed by the high time defined in the protocol (nominal values, may vary by tolerance of internal RC oscillator, not including analog delay of the open drain output and influence by external circuitry, unit time programming see Section 12.2). All values are multiples of a unit time frame concept. A transfer consists of the following parts: • • • • • A synchronization period of 56 UT (in parallel, a new sample is calculated) A status nibble of 12-27 UT Three data nibbles of 12-27 UT (data packet 1 with a length of 36-81 UT) Three data nibbles of 12-27 UT (data packet 2 with a length of 36-81 UT) A CRC nibble of 12-27 UT Sensor processing compensate the sample transfer compensated sample Output pin (physical) Next sampe Sampling point: values taken from decimation filter register Transferred data (logical) sync. period Figure 11 Status nibble Data nibble 1 high Data nibble 1 mid Data nibble 2 low CRC nibble SENT Frame The CRC checksum includes the status nibble and the data nibbles and can be used to check the validity of the decoded data. The sensor is available for the next sample 90µs after the falling edge of the end pulse. This leads to a minimum transfer time of 152 UT, and a maximum transfer time of 272 UT per sample. Data Sheet 31 Rev 1.1, 2009-09 TLE4998S3C SENT Output Definition (SAE J2716) It is important to know that the sampling time (when values are taken for temperature compensation) here is always defined as the beginning of the synchronization period; during this period, the resulting data is always calculated from scratch. As only one Hall value needs to be transferred within one sequence, the second data package is divided into two parts (see Table 19): • First, the remaining 4 LSBs of the Hall signals are transferred in the first data nibble. This means the receiver may use the whole 16-bit data available in the sensor when reading and using all 4 nibbles transferred. • Second, the temperature is transferred as an 8-bit value. The value is transferred in unsigned integer format and corresponds to -55°C to 200°C. For example, transferring the value 55 corresponds to 0°C. The temperature is additional information and although it is not calibrated, may be used for a plausibility check, for example. Table 17 Mapping of Temperature Value Junction Temperature Typ. Decimal Value from Sensor Note - 55°C 0 0°C 55 25°C 80 200°C 255 1) Theoretical lower limit1) Theoretical upper limit1) Theoretical range of temperature values, not operating temperature range The status nibble allows to check internal states and conditions of the sensor. • The first two bits of the status nibble contain the selected magnetic range of the sensor and therefore allow the received data to be interpreted easily. • The third bit is set to “1” for the first transmission after the sensor returns from an overvoltage operation with disabled open drain stage to regular operation (see Chapter 7.1). • The fourth bit is switched to “1” for the first data package transferred after a reset. This allows the detection of low-voltage situations or EMC problems of the sensor. 12.2 Unit Time Setup The basic SENT protocol unit time granularity is defined as 3 µs. Every timing is a multiple of this basic time unit. To achieve more flexibility, trimming of the unit time can be used to: • Allow a calibration trim within a timing error of less than 20% clock error (as given in SAE standard) • Allow a modification of the unit time for small speed adjustments Data Sheet 32 Rev 1.1, 2009-09 TLE4998S3C SENT Output Definition (SAE J2716) This enables a setup of different unit times, even if the internal RC oscillator varies by ±20%. Of course, timing values that are too low could clash with timing requirements of the application and should therefore be avoided, but in principle it is possible to adjust the timer unit for a more precise protocol timing. The output characteristic depends on the external load, the wiring, as well on the pull-up voltage and the temperature. All these parameters have considerable influence to find the proper unit time setup. Table 18 Parameter Predivider Setting Symbol Limit Values min. Register size Prediv Unit time tUNIT 2.0 Unit Notes 4 bit Predivider1) 4.0 µs ClkUNIT=8MHz2) max. 1) Useable predivider range is decimal 7 to 15. Prediv < 7 is internally kept at 7. Prediv default is decimal = 11 for 3 µs nominal unit time 2) RC oscillator frequency variation +/- 20% The nominal unit time is calculated by: tUNIT = (Prediv × 2 + 2) / ClkUNIT ClkUNIT = 8MHz ±20% Data Sheet 33 Rev 1.1, 2009-09 TLE4998S3C SENT Output Definition (SAE J2716) Table 19 Content of a SENT Data Frame (8 Nibbles) DATA WORD 1 SYNC bits STATUS D1 MSN D1 MidN DATA WORD 2 D1 LSN D2 MSN D2 MidN description D2 LSN CRC description state range status and current range 10 RR startup condition in range RR 01 RR overvoltage in range RR CRC calculation for all nibbles on the basis of SAE J2716 00 RR normal state using range RR seed value: 0101 4 3 2 polynomial: X +X +X +1 bits description 11 +/- 50mT 01 +/- 100mT 00 +/- 200mT bits description1 description 2 decimal: OUT12 decimal: OUT16 ( = D1MSN*256 +D1MidN*16+D1LSN ) ( = OUT12*16+D2MSN ) 1111 4095 (FSR) 1110 4095 1111 : 1111 1111 1111 1111 1111 1111 1111 D1 MSN D1 MidN D1 LSN D2MSN 1111 1111 1111 1111 1111 1111 1111 1111 1111 bits description decimal: TEMP8 D2MidN D2LSN 65535 (FSR) 1111 1111 200 °C 65534 1111 1110 199 °C 4095 : 1111 : : 0000 4095 65520 1111 0000 185 °C 1110 1111 4094 65519 1110 1111 184 °C 1110 1110 4094 65518 : : : 1111 1110 : 4094 : 0101 0000 25 °C 1111 1111 1110 0000 4094 65504 0100 1111 24 °C 1111 1111 1101 1111 4093 65503 : : : : : : : : : 0011 0111 0°C 0000 0000 0010 0000 2 32 0011 0110 -1°C 0000 0000 0001 1111 1 31 : : : 0000 0000 0001 : 1 : 0000 0001 -54 °C 0000 0000 0001 0000 1 16 0000 0000 -55 °C 0000 0000 0000 1111 0 15 0000 0000 0000 1110 0 14 0000 0000 0000 : 0 : 0000 0000 0000 0001 0 1 0000 0000 0000 0000 0 0 Data Sheet 34 ( = D2MidN* 16+D2LSN ) Abbreviations: SYNC – synchronization nibble STATUS – status nibble CRC – cyclic redundancy code nibble FSR – full scale range MSN – most significant nibble MidN – middle nibble LSN – least significant nibble OUT12 – 12 bit output value OUT16 – 16 bit output value TEMP8 – 8 bit temperature value Rev 1.1, 2009-09 TLE4998S3C SENT Output Definition (SAE J2716) 12.3 Checksum Nibble Details The Checksum nibble is a 4-bit CRC of the data nibbles including the status nibble. The CRC is calculated using a polynomial x4 +x3 + x2 + 1 with a seed value of 0101. In the TLE4998S3C it is implemented as a series of XOR and shift operations as shown in the following flowchart: CRC calculation Pre-initialization : Nibble next Nibble VALUE GENERATOR = 1101 xor SEED = 0101 , use this constant as old CRC value at first call SEED <<1 VALUE VALUExor xorSEED SEED 0 4x xor only if MSB = 1 GENPOLY Figure 12 CRC Calculation A microcontroller implementation may use an XOR command plus a small 4-bit lookup table to calculate the CRC for each nibble. // Fast way for any µC with low memory and compute capabilities char Data[8] = {…}; // contains the input data (status nibble , 6 data nibble , CRC) // required variables and LUT char CheckSum, i; char CrcLookup[16] = {0, 13, 7, 10, 14, 3, 9, 4, 1, 12, 6, 11, 15, 2, 8, 5}; CheckSum= 5; // initialize checksum with seed "0101" for (i=0; i<7; i++) { CheckSum = CheckSum ^ Data[i]; CheckSum = CrcLookup[CheckSum]; } ; // finally check if Data [7] is equal to CheckSum Figure 13 Data Sheet Example Code for CRC Generation 35 Rev 1.1, 2009-09 w w w . i n f i n e o n . c o m Published by Infineon Technologies AG