Dynamic Differential Hall Effect Sensor IC TLE 4921-3U Bipolar IC Features • • • • • • • • • • • • • • • Advanced performance High sensitivity Symmetrical thresholds High piezo resistivity Reduced power consumption South and north pole pre-induction possible AC coupled Digital output signal Two-wire and three-wire configuration possible Large temperature range Large airgap Low cut-off frequency Protection against overvoltage Protection against reversed polarity Output protection against electrical disturbances P-SSO-4-1 Type Marking Ordering Code Package TLE 4921-3U 21C3U Q67006-A9171 P-SSO-4-1 The differential Hall Effect sensor TLE 4921-3U provides a high sensitivity and a superior stability over temperature and symmetrical thresholds in order to achieve a stable duty cycle. TLE 4921-3U is particularly suitable for rotational speed detection and timing applications of ferromagnetic toothed wheels such as anti-lock braking systems, transmissions, crankshafts, etc. The integrated circuit (based on Hall effect) provides a digital signal output with frequency proportional to the speed of rotation. Unlike other rotational sensors differential Hall ICs are not influenced by radial vibration within the effective airgap of the sensor and require no external signal processing. Data Sheet 1 2000-07-01 TLE 4921-3U Pin Configuration (view on branded side of component) Center of sensitive area ±0.15 1.53 2.67 2.5 1 2 3 4 VS Q GND C AEP01694 Figure 1 Pin Definitions and Functions Pin No. Symbol Function 1 VS Supply voltage 2 Q Output 3 GND Ground 4 C Capacitor Data Sheet 2 2000-07-01 TLE 4921-3U VS 1 Protection Device Internal Reference and Supply Vreg (3V) Hall-Probes Amplifier GND Data Sheet Open Collector Protection Device 2 Q 4 3 Figure 2 SchmittTrigger HighpassFilter CF AEB01695 Block Diagram 3 2000-07-01 TLE 4921-3U Functional Description The Differential Hall Sensor IC detects the motion and position of ferromagnetic and permanent magnet structures by measuring the differential flux density of the magnetic field. To detect ferromagnetic objects the magnetic field must be provided by a back biasing permanent magnet (south or north pole of the magnet attached to the rear unmarked side of the IC package). Using an external capacitor the generated Hall voltage signal is slowly adjusted via an active high pass filter with a low cut-off frequency. This causes the output to switch into a biased mode after a time constant is elapsed. The time constant is determined by the external capacitor. Filtering avoids aging and temperature influence from Schmitt-trigger input and eliminates device and magnetic offset. The TLE 4921-3U can be exploited to detect toothed wheel rotation in a rough environment. Jolts against the toothed wheel and ripple have no influence on the output signal. Furthermore, the TLE 4921-3U can be operated in a two-wire as well as in a three-wireconfiguration. The output is logic compatible by high/low levels regarding on and off. Circuit Description (see Figure 2) The TLE 4921-3U is comprised of a supply voltage reference, a pair of Hall probes spaced at 2.5 mm, differential amplifier, filter for offset compensation, Schmitt trigger, and an open collector output. The TLE 4921-3U was designed to have a wide range of application parameter variations. Differential fields up to ± 80 mT can be detected without influence to the switching performance. The pre-induction field can either come from a magnetic south or north pole, whereby the field strength up to 500 mT or more will not influence the switching points. The improved temperature compensation enables a superior sensitivity and accuracy over the temperature range. Finally the optimized piezo compensation and the integrated dynamic offset compensation enable easy manufacturing and elimination of magnet offsets. Protection is provided at the input/supply (pin 1) for overvoltage and reverse polarity and against overstress such as load dump, etc., in accordance with ISO-TR 7637 and DIN 40839. The output (pin 2) is protected against voltage peaks and electrical disturbances. Data Sheet 4 2000-07-01 TLE 4921-3U Absolute Maximum Ratings Tj = – 40 to 150 °C Parameter Symbol Limit Values min. Supply voltage Output voltage Output current Output reverse current Capacitor voltage Junction temperature Junction temperature Junction temperature Junction temperature Storage temperature Thermal resistance P-SSO-4-1 Current through inputprotection device Current through outputprotection device Unit Remarks max. 1) VS VQ IQ – IQ VC Tj Tj Tj Tj TS Rth JA – 35 30 V – – 0.7 30 V – – 50 mA – – 50 mA – – 0.3 3 V – – – – – 150 160 170 210 °C °C °C °C 5000 h 2500 h 1000 h 40 h – 40 150 °C – – 190 K/W – ISZ – 200 mA t < 2 ms; v = 0.1 IQZ – 200 mA t < 2 ms; v = 0.1 V V V V V V td = 2 ms td = 0.05 ms td = 0.1 µs td = 0.1 µs td ≤ 20 s td = 400 ms; RP = 400 Ω Electro Magnetic Compatibility ref. DIN 40839 part 1; test circuit 1 Testpulse 1 Testpulse 2 Testpulse 3a Testpulse 3b Testpulse 4 Testpulse 5 1) VLD VLD VLD VLD VLD VLD – 100 100 – 150 100 –7 120 Reverse current < 10 mA Note: Stresses above those listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Data Sheet 5 2000-07-01 TLE 4921-3U Operating Range Parameter Symbol Limit Values Unit Remarks min. max. 4.5 24 V – – 40 170 °C – Pre-induction VS Tj B0 – 500 500 mT at Hall probe; independent of magnet orientation Differential induction ∆B – 80 80 mT – Supply voltage Junction temperature Note: In the operating range the functions given in the circuit description are fulfilled. AC/DC Characteristics Parameter Symbol Unit Test Condition min. typ. max. 4.7 6.1 8.0 mA 5.1 6.7 8.8 mA Test Circuit Output saturation voltage VQSat – 0.25 0.6 V VQ = high IQ = 0 mA VQ = low IQ = 40 mA IQ = 40 mA Output leakage current IQL – – 10 µA VQ = 24 V Center of switching points: (∆BOP + ∆BRP) / 2 ∆Bm –1 0 1 mT – 20 mT < ∆B < 2 20 mT 1) 2) f = 200 Hz Operate point ∆BOP – – 0 mT 2 Release point ∆BRP 0 – – mT Hysteresis ∆BHy 0.5 1.5 2.5 mT f = 200 Hz, ∆B = 20 mT f = 200 Hz, ∆B = 20 mT f = 200 Hz, ∆B = 20 mT 27 27 – – 35 35 V V 1 1 – – 0.5 µs IS = 16 mA IS = 16 mA IQ = 40 mA CL = 10 pF Supply current IS Limit Values Overvoltage protection at supply VSZ voltage at output VQZ Output rise time Data Sheet tr 6 1 1 1 1 2 2 1 2000-07-01 TLE 4921-3U AC/DC Characteristics (cont’d) Parameter Symbol Limit Values min. typ. max. Unit Test Condition Test Circuit IQ = 40 mA CL = 10 pF f = 10 kHz ∆B = 5 mT 1 Output fall time tf – – 0.5 µs Delay time3) tdop tdrp tdop - tdrp RC – – – – – 0 25 10 15 µs µs µs 32 40 48 kΩ 25 °C ± 2 °C 1 Filter sensitivity to ∆B SC – –4 – mV/ mT – 1 Filter bias voltage VC 0.8 – 2.2 V ∆B = 0 1 Frequency f 4) – 20000 Hz ∆B = 5 mT 2 Resistivity against mechanical stress (piezo) ∆ Bm ∆BHy – 0.1 – 0.1 – 0.1 0.1 F=2N 25) Filter input resistance 1) mT mT 2 Leakage currents at pin 4 should be avoided. The bias shift of Bm caused by a leakage current IL can be I L × RC ( T ) calculated by:∆ B m = ------------------------------ . SC ( T ) 2) For higher ∆B the values may exceed the limits like following | ∆Bm | < | 0.05 × ∆B | 3) For definition see page 16. 4) 1 Depends on filter capacitor CF. The cut-off frequency is given by f = ---------------------------------- . The switching points are 2π × R C × C F guaranteed over the whole frequency range, but amplitude modification and phase shift due to the 1st order highpass filter have to be taken into account. 5) See page 17. Note: The listed characteristics are ensured over the operating range of the integrated circuit. Typical characteristics specify mean values expected over the production spread. If not otherwise specified, typical characteristics apply at Tj = 25 °C and the given supply voltage. Data Sheet 7 2000-07-01 TLE 4921-3U RP ΙS V SZ 300 Ω 1 VS VLD RL Ι Q , Ι QR 1) ΙC VS 4 C Q 2 4.7 nF 1) RC = V QSat , V QZ GND 3 VC ∆VC ∆Ι C Figure 3 CL AES01696 Test Circuit 1 1 VS 4 VS C Q CF 470 nF 1 kΩ GND 3 2 VQ f min f max ∆ B OP ∆ B Hy AES01258 Figure 4 Data Sheet Test Circuit 2 8 2000-07-01 TLE 4921-3U Application Configurations Two possible applications are shown in Figure 7 and 8 (Toothed and Magnet Wheel). The difference between two-wire and three-wire application is shown in Figure 9. Gear Tooth Sensing In the case of ferromagnetic toothed wheel application the IC has to be biased by the south or north pole of a permanent magnet (e.g. SmCO5 (Vacuumschmelze VX145) with the dimensions 8 mm × 5 mm × 3 mm) which should cover both Hall probes. The maximum air gap depends on – the magnetic field strength (magnet used; pre-induction) and – the toothed wheel that is used (dimensions, material, etc.; resulting differential field) a centered distance of Hall probes b Hall probes to IC surface L IC surface to tooth wheel N S b L a a = 2.5 mm b = 0.3 mm AEA01259 Figure 5 Sensor Spacing Conversion DIN – ASA T m = 25.4 mm/p T = 25.4 mm CP d AEA01260 DIN ASA d diameter (mm) p diameter pitch p z number of teeth PD pitch diameter PD = z/p (inch) m module m = d/z (mm) CP circular pitch T pitch T = π × m (mm) Figure 6 Data Sheet = z/d (inch) CP = 1 inch × π/p Toothed Wheel Dimensions 9 2000-07-01 TLE 4921-3U Gear Wheel Hall Sensor 1 Hall Sensor 2 Signal Processing S (N) Circuitry Permanent Magnet N (S) Figure 7 AEA01261 TLE 4921-3U, with Ferromagnetic Toothed Wheel Magnet Wheel S S N Hall Sensor 1 Hall Sensor 2 Signal Processing AEA01262 Circuitry Figure 8 Data Sheet TLE 4921-3U, with Magnet Wheel 10 2000-07-01 TLE 4921-3U Two-wire-application Line 1 VS 4 C VS RL Q 2 GND 3 CF 470 nF VSIGNAL RS Sensor Mainframe for example : R L = 330 Ω R S = 120 Ω AES01263 Three-wire-application Rp 4 CF 470 nF 1 VS C Q 2 GND 3 VSIGNAL 4.7 nF 4.7 nF Mainframe for example : R L = 330 Ω R P = 0 ... 330 Ω Data Sheet VS RL Sensor Figure 9 Line AES01264 Application Circuits 11 2000-07-01 TLE 4921-3U N (S) S (N) 1 4 B1 B2 Wheel Profile Missing Tooth Small Airgap Magnetic Field Difference ∆ B = B2-B1 Large Airgap ∆ B RP = 0.75 mT ∆ B HYS ∆ B OP = -0.75 mT Output Signal VQ Operate point : B2 - B1 < ∆ B OP switches the output ON (VQ = LOW) Release point : B2 - B1 > ∆ B RP switches the output OFF (VQ = HIGH) ∆ B RP = ∆ BOP + ∆ B HYS The magnetic field is defined as positive if the south pole of the magnet shows towards the rear side of the IC housing. AED01697 Figure 10 System Operation Data Sheet 12 2000-07-01 TLE 4921-3U Quiescent Current versus Temperature Quiescent Current versus Supply Voltage AED01698 10.0 ΙS mA Ι Q ON = 40 mA 7.5 Ι S ON AED01699 10.0 ΙS Ι Q ON = 40 mA mA 7.5 Ι S ON Ι S OFF 5.0 5.0 2.5 2.5 Ι S OFF Ι S diff 0 0 5 10 15 0 -50 25 V 0 50 100 VS ˚C 200 Ta Quiescent Current Difference versus Temperature Quiescent Current versus Output Current AED01700 1.0 AED01701 10.0 ΙS ∆Ι S Ι Q ON = 40 mA mA mA VS = 12 V 7.5 0.75 Ι S ON Ι S ON - Ι S OFF 0.5 5.0 0.25 2.5 0 0 5 10 15 0 25 V 10 20 30 mA 50 ΙQ VS Data Sheet 0 13 2000-07-01 TLE 4921-3U Saturation Voltage versus Temperature Saturation Voltage versus Output Current AED01702 0.4 VQ VQ VS = 4.5 V Ι Q = 50 mA V AED01703 0.3 V Ta = 25 ˚C 0.2 0.3 0.1 0 0.2 -0.1 -0.2 0.1 -0.3 0 -50 0 50 100 ˚C -0.4 -50 200 -30 -10 10 30 mA 50 ΙQ Ta Saturation Voltage versus Supply Voltage Switching Points versus Preinduction AED01704 0.4 VQ Ι Q = 40 mA Ta = 25 ˚C V AED01705 2.0 mT BRP, (-B OP ) 0.3 0.2 -80 mT < ∆B < 80 mT 1.5 1.0 typ 0.1 0 0.5 0 5 10 15 V 0 -500 25 VS Data Sheet -250 0 500 mT BO 14 2000-07-01 TLE 4921-3U Switching Induction versus Temperature AED01706 2 Bm B HY typ 1.5 min -1 0 50 max 2.5 typ 0 B HY = B RP - B OP f = 200 Hz mT max 1 AED01707 3.5 B m = ( B OP + B RP ) /2 f = 200 Hz mT -2 -50 Hysteresis versus Temperature min 0.5 100 ˚C 0 -50 200 0 50 100 Minimum Switching Field versus Frequency Minimum Switching Field versus Frequency AED01708 B min mT 200 Ta Ta 3.0 ˚C AED01709 3.5 B min C = 940 nF 2.5 mT 3.0 C = 940 nF 2.5 2.0 2.0 1.5 1.5 1.0 0.5 0 0.001 0.01 Ta = 170 ˚C Ta = -40 ˚C 1.0 Ta = 25 ˚C 0.5 0.1 1 kHz 0 0.001 100 0.01 0.1 1 kHz 100 f f Data Sheet Ta = 150 ˚C 15 2000-07-01 TLE 4921-3U Delay Time1) between Switching Threshold ∆B and Falling Edge of VQ at Tj = 25 °C Delay Time1) between Switching Threshold ∆B and Rising Edge of VQ at Tj = 25 °C AED01711 30 AED01710 30 t drp µs t dop µs BOP t drp 25 t dop 25 B RP 20 20 15 15 ∆ B = 1.2 mT ∆ B = 1.2 mT 10 10 ∆ B = 5 mT 5 5 0 0 5 0 10 15 kHz 25 ∆ B = 5 mT 5 0 10 15 kHz f f 1) 1) Delay Time versus Differential Field Delay Time versus Temperature AED01712 30 t d µs 25 AED01713 30 t d µs f = 10 kHz 25 25 20 20 f = 10 kHz ∆ B = 2 mT t d op 15 15 10 10 t d rp t d op 5 0 5 t d rp 0 20 40 60 mT 0 -50 100 ∆B 1) 0 50 100 ˚C 200 Ta Switching points related to initial measurement @∆B = 2 mT, f = 200 Hz Data Sheet 16 2000-07-01 TLE 4921-3U Rise and Fall Time versus Temperature t Rise and Fall Time versus Output Current AED01714 100 ns 90 AED01715 120 t Ι Q = 40 mA ns Ta = 25 ˚C 100 80 70 80 60 50 60 tf 40 tr tr 40 30 tf 20 20 10 0 -50 0 50 100 ˚C 0 200 0 10 20 30 mA ΙQ Ta Capacitor Voltage versus Temperature VC Switching Thresholds versus Mechanical Stress AED01716 3.0 50 AED01717 1.0 V F mT 2.5 r = 0.5 ∆ B RP ,(− ∆ B OP ) 0.9 2.0 typ 1.5 0.8 max min 0.7 1.0 0.6 0.5 0 -50 0 50 100 ˚C 0.5 200 Ta Data Sheet 0 1 2 3 5 N F 17 2000-07-01 TLE 4921-3U Filter Sensitivity versus Temperature Filter Input Resistance versus Temperature AED01718 -5 S C mV mT RC AED01719 2 R C (25 ˚C) VS = 12 V -4 1.5 typ max -3 min 1 -2 0.5 -1 0 -50 0 50 100 ˚C 0 -50 200 Ta 0 50 100 ˚C 200 Ta Delay Time for Power on (VS Switching from 0 V to 4.5 V) tpon versus Temp. AED02646 0.35 k ms nF 0.30 0.25 max 0.20 min 0.15 0.10 0.05 0 -50 0 50 100 C 200 Ta Data Sheet 18 2000-07-01 TLE 4921-3U Package Outlines 5.38 ±0.05 5.16 ±0.08 12.7 ±1 0.2 1x45˚ 1 -0.1 0.25 ±0.05 0.2 +0.1 0.6 max. 9 +0.75 -0.5 1.27 3.81 1 -1 4 6 ±0.5 1 23.8 ±0.5 38 max. 0.4 +0.05 18 ±0.5 (0.25) 3.38 ±0.06 3.71 ±0.08 1 max. 1.9 max. 0.15 max. P-SSO-4-1 (Plastic Single Small Outline Package) 0.25 -0.15 Adhesive Tape 6.35 ±0.4 12.7 ±0.3 4 ±0.3 0.5 ±0.1 GPO05357 Tape d Branded Side Hall-Probe d : Distance chip to upper side of IC P-SSO-4-1 : 0.3 ±0.08 mm AEA02712 Sorts of Packing Package outlines for tubes, trays etc. are contained in our Data Book “Package Information”. Data Sheet 19 Dimensions in mm 2000-07-01