SENSOR PRODUCTS APPLICATIONS Linear Displacement Angular Displacement Linear / Angular / Rotary Displacement Sensors HMC1501 / HMC1512 Motor Control H Valve Position Proximity Detection Current Spike Detection Not actual size igh resolution, low power MR sensor capable of measuring the angle direction of a magnetic field from a magnet with <0.07° resolution. Advantages of measuring field direction versus field strength include: insensitivity to the tempco of the magnet, less sensitivity to shock and vibration, and the ability to withstand large variations in the gap between the sensor and magnet. These sensors may be operated on 3 volts with bandwidth response of 0-5 MHz. Output is typical Wheatstone bridge. FEATURES AND BENEFITS No Rare Earth Magnets Unlike Hall effect devices which may require samarium cobalt or similar “rare earth” magnets, the HMC1501 and HMC1512 can function with Alnico or ceramic type magnets. Wide Angular Range HMC1501—Angular range of ±45° with <0.07° resolution. HMC1512—Angular range of ±90° with <0.05° resolution. Effective Linear Range Linear range of 8mm with two sensors mounted on two ends; range may be increased through multiple sensor arrays operating together. Absolute Sensing Unlike incremental “encoding” devices, sensors know the exact position and require no indexing for proper positional output. Non-Contact Sensing No moving parts to wear out; no dropped signals from worn tracks as in conventional contact based rotary sensors. Small Package Available in an 8-pin surface mount package with case dimensions (exclusive of pins), of 5mm x 4mm x 1.2mm total mounting envelope, with pins of less than 6mm square. Large Signal Output Full Scale output range of 120mV with 5V of power supply. HMC1501 / HMC1512 SENSOR PRODUCTS PRINCIPLES OF OPERATION Anisotropic magnetoresistance (AMR) occurs in ferrous materials. It is a change in resistance when a magnetic field is applied in a thin strip of ferrous material. The magnetoresistance is a function of cos2θ where θ is the angle between magnetization M and current flow in the thin strip. When an applied magnetic field is larger than 80 Oe, the magnetization aligns in the same direction of the applied field; this is called saturation mode. In this mode, θ is the angle between the direction of applied field and the current flow; the MR sensor is only sensitive to the direction of applied field. Metal Contact Current Flow M θ Permalloy Thin Film (NiFe) Applied Field Applied Field Direction M M The sensor is in the form of a Wheatstone bridge (Figure 1). The resistance R of all four resistors is the same. The bridge power supply VS causes current to flow through the resistors, the direction as indicated in the figure for each resistor. R+∆R R-∆R ∆V Both HMC1501 and HMC1512 are designed to be used in saturation mode. HMC1501 contains one MR bridge and HMC1512 has two identical MR bridges, coexisting on a single die. Bridge B physically rotates 45° from bridge A. The HMC1501 has sensor output ∆V=-VSS sin (2θ) and the HMC1512 has sensor output ∆V=VSS sin (2θ) for sensor A and sensor B output ∆VS=-VSS cos (2θ), where VS is supply voltage, S is a constant, determined by materials. For Honeywell sensors, S is typically 12mV/V. I Vs +M M R+∆R R-∆R Figure 1 PINOUT DRAWINGS HMC1512 HMC1501 • OUT+ 1 GND 1 2 3 4 θ OUT- A OUT- B VBRIDGEB VBRIDGEA 8 OUT7 GND 2 6 5 VBRIDGE • 1 2 3 4 8 7 6 5 θ GNDA GNDB OUT+ B OUT+ A Caution: Do not connect GND or Power to Pin 3,4 &6. MR SENSOR CIRCUITS VBRIDGE A VBRIDGE OUT +B VBRIDGE B R R R R R R OUT+ OUT- R GND 1 OUT+ A OUTA Bridge A R R GND 2 GND A 2 R Bridge B R R GND B OUT -B HMC1501 / HMC1512 SENSOR PRODUCTS TYPICAL SENSOR OUTPUT 60 40 20 0 -20 0 -40 -60 -80 -100 HMC1512 output voltage vs. magnetic field angle 100 100 200 300 Sensor Output (mV) Sensor Output (mV) HMC1501 output voltage vs. magnetic field angle 400 50 0 0 100 200 300 -100 Theta (degree) Bridge A Bridge BB Theta (degree) A APPLICATION CONFIGURATION Linear Position Moving Direction Proximity Position N S Moving Direction 400 -50 θ Valve Actuator Stem N Reference Direction ~0.5 to -1.5 inches Rotary Position HMC1501/1512 MR Sensor Magnet Magnet S N N S N Rotating Shaft S Rotating Shaft PACKAGE DRAWING 8-Pin SOIC D A1 Symbol A A1 B D E e H h A H E 1 • e B h x 45° 3 Millimeters Inches Min Max 1.371 1.728 0.101 0.249 0.355 0.483 4.800 4.979 3.810 3.988 1.270 ref 5.816 6.198 0.381 0.762 Max Min .068 .054 .010 .004 .019 .014 .196 .189 .157 .150 .050 ref .244 .229 .030 .015 HMC1501 / HMC1512 SENSOR PRODUCTS SPECIFICATIONS Characteristics Conditions* Min Bridge supply HMC1512 Typ Max Units 1 5 25 1 5 25 V Bridge current—1 mA 4 5 6.5 2.0 2.1 2.8 KΩ > Saturation field -45 +45 -90 +90 deg Angle range Vbridge = 5V, field 80 Oe, (1) @ zero crossing (2) @ Zero crossing, averaged in the range of 45° Peak -to-peak Voltage Vbridge = 5V, field = 80 Oe Bridge offset Field 80 Oe, θ =0° Saturation field Min Vbridge referenced to GND Bridge resistance Sensitivity HMC1501 Typ Max Bridge A Bridge B 2.1 1.8 2.1 1.8 mV/° 100 120 140 100 120 140 mV -7 3 7 0 -4 2. 5 0 5 1 mV/V Repeatability <0.03% FS 80 Bandwidth Magnetic signal 0 Resolution Bandwidth =10Hz,Vbridge =5V 0.07 0.05 ° Hysteresis error Magnetic field >saturation field, Vbridge = 5V 30 1.7x10-2 30 1.7x10-2 µV deg Bridge Ω tempco TA = -40° C to +125° C 0.28 0.28 %/° C Sensitivity tempco TA = -40° C to +125° C Vbridge = 5V -0.32 -0.32 %/° C Bridge offset tempco TA = -40° C to +125° C -0.01 -0.01 %/° C, FS Noise at 1Hz, Vbridge = 5V 10 0 70 nV Hz Vbridge = 5V 5 23 mW Noise Density Power Consumption *Tested at 25°C except stated otherwise. Where 5 G 0 5 MHz Offset tempco Co = Vo (t) - Vo (o) = -0.01%/°C VP-P*t Where Vo (o) = bridge offset at zero temperature VP-P = peak-to-peak voltage t = temperature in the range -40°C to 125°C Vo (t) = offset at temperature t Sensitivity tempco Cs = St-So = -0.32%/°C So*t Where So = sensitivity at zero temperature t = temperature in the range -40°C to 125°C St = sensitivity at temperature t Power consumption P = 80 V2 R 1 KA/m = 12.5 Gauss 1 Tesla = 104 Gauss V = Bridge supply voltage R = Bridge resistance Honeywell reserves the right to make changes to any products or technology herein to improve reliability, function or design. Honeywell does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Solid State Electronics Center 12001 State Highway 55 Plymouth, MN 55441 1-800-323-8295 http://www.ssec.honeywell.com 900246 8-00 Rev. B 4