DESCRIPTION The VF401 is a high performance, digital, 2-wire, MR The VF401 has a reduced sensitivity to run-out (shift in sensor (magnetoresistive) sensor in a miniature, flat, TO-92-style, position relative to the inside or outside diameter of the ring plastic package with a current output, designed for sensing fine magnet). It is also less sensitive to tilt tolerance (deviation from pitch ring magnets. parallel positioning of the sensing elements and ring magnet), accepting up to 10, versus only 2 to 3 for typical ring magnet The unique VF401 bridge array (patent number 6,297,628) has sensors, as well as being less sensitive to twist (deviation of been optimized to allow a greater air gap between the target perfect angular position of the bridge runners relative to the and the sensor with reduced loss in sensor signal or accuracy. pole transitions). FEATURES AND BENEFITS POTENTIAL APPLICATIONS Robust design operating from -40 C to 150 C -40 F to Transportation 302 F can withstand short durations up to 175 C 347 F , Speed encoding using a multipole ring magnet allowing use in potential applications with extreme Enhanced accuracy rotational position sensing temperature requirements. Wheel speed sensing Not damaged by reverse polarity voltages when customer- Window lift applications supplied sense resistor is installed, enhancing protection. Patented MR bridge optimized for stable sensing of 20- to Speed and direction sensing 50-pole pair ring magnets with improved insensitivity to run- out, tilt and twist. Industrial 2-wire digital current output simplifies wiring and interfacing Shaft speed encoding using a multipole ring magnet which can reduce total system cost Enhanced accuracy rotational position sensing Enhanced sensitivity, 7 Gauss typical, allows for larger air Precision motor speed measurement gaps (up to 2,5 mm 0.098 in ) and higher pole density (up to 50-pole pairs depending on ring diameter). Speed control in machine tools One pulse per pole pair output and differential bridge Elevator speed sensing operation allow compatibility with differential Hall sensors Speed control in motorized industrial equipment which can make it easier to upgrade existing applications. Wide speed capability provides application flexibility with true Medical zero speed sensing and operation up to 3000 Hz. Shaft speed encoding using a multipole ring magnet Output pattern independent of gap between target and sensor. RoHS-compliant materials meet Directive 2002/95/EC. 1 Table 1. Absolute Maximum Ratings Characteristic Min. Typ. Max. Unit 2 Supply voltage -18 +18 V Magnetic flux gauss no limit 175 347 for 10 min C F Temperature at 10 cycles Frequency 3000 Hz Notes: 1. Absolute maximum ratings are the extreme limits the device will momentarily withstand without damage to the device. Electrical and magnetic characteristics are not guaranteed if the rated voltage and/or currents are exceeded nor will the device necessarily operate at absolute maximum ratings. 2. Customer-supplied sense resistor is required for negative reverse voltage. Table 2. Specifications (Established using a 65,00 mm 2.559 in diameter, 48-pole pair ring magnet.) Characteristic Condition Min. Typ. Max. Unit 1 Vcc V Vh (V+ to V-) 4.5 16 V Icc operate 11.8 14 16.80 mA Icc released 5.9 7 8.40 mA Icc ratio (op/rel) 1.9 2.0 2.3 Rise time,10% to 90% Vcc = 12 V, R = 150 Ohm, C = 1000 pF, 1.5 s L L 25 C 77 F Fall time, 10% to 90% Vcc = 12 V, R = 150 Ohm, C = 1000 pF, 1.5 s L L 25 C 77 F Operating temperature -40 -40 150 302 C F Differential magnetic field over entire MR bridge area: Gauss operate +7 release -7 2 Air gap 0.75 0.030 2.5 0.098 mm in Duty cycle 30 50 70 % Notes: 1. Vcc is limited by Vh and the value chosen for the sense resistor. 2. Sensor operation at limits for air gap is dependent on ring magnet. Table 3. ESD and EMC Performance Test Specification Condition Results ESD (Electrostatic Discharge) GMW3100GS Class 3 (low sensitivity) 1 Electrical Transient Transmission ISO 7637-3 electrical capacitance and inductive coupling Class B 2 Radiated Immunity ISO 11452-3 0.1 MHz to 12 GHz, 80% AM at 1 kHz Class A at 100 V/m Notes: 1. Class B: One or more functions may be out of specification during disturbance, but will automatically return to normal after exposure is removed. 2. Class A: All functions remain within specification during and after exposure to disturbance. 2 www.honeywell.com/sensing