DM-231 Magnetoresistance Element For the availability of this product, please contact the sales office. Description DM-231 a magnetic sensor using magnetoresistance effect is composed of ferromagnetic material deposited by evaporation on a silicon substrate. It is suitable for angle of rotation detection. M-118 (Plastic) Features • Low magnetic field and high sensitivity: bridge type stands for large output voltage 150 mVp-p (Min.) at VCC=5 V, H=14400 A/m • Fitted with bias magnet: stable output. • High reliability: Achieved through silicon nitride protective film. Structure Ferromagnetic thin film circuit (With ferrite magnet) Applications • Non-contact angle of rotation detection. • Contactless potentiometer. Absolute Maximum Ratings (Ta=25 °C) • Supply voltage VCC 10 –30 to +100 V °C Recommended Operating Conditions • Supply voltage VCC 5 • Operating temperature Topr –20 to + 75 V °C • Storage temperature Tstg Electrical Characteristics Item Output voltage Midpoint potential Midpoint potential difference/Output voltage Total resistance Ta=25 °C Symbol VO VA, VB |VA-VB| VO RT Condition VCC=5 V , H=14400 A/m (Peak) AC magnetic field θ =0 ° VCC=5 V , H=0 A/m Min. Typ. 150 2.475 500 Unit mVp-p VCC=5 V , H=0 A/m H=14400 A/m (Peak) AC magnetic field θ =0 ° Max. 650 2.525 V 15 % 800 Ω Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. —1— E88Z12C5X-TE DM-231 Equivalent Circuit 1 VCC RD RA 2 VA 4 VB RC RB 3 GND Basic Performance 1) Operation principle External magnetic field H 1 AAAAAA A AAAAAAAA AA A RA RD RB RC 2 Synthetic magnetic field (a) Various resistances change according to the direction of the combnied bias and external magnetic field. ¡) When the direction of the synthetic magnetic field is (a), RA,RC : Maximum resistance RB,RD : Minimum resistance ¡¡) When the direction of the synthetic magnetic field is (b), 4 RA,RC : Minimum resistance RB,RD : Maximum resistance 3 Bias magnetic field H=14400A/m External magnetic field H Synthetic magnetic field (b) ∗ Device internal structure (Back of mark face) Bias magnetic field 3 2 4 1 2) Power supply pin and output pin 2 231 3) Sensitivity direction Non-Sensitive 3 4 1 VCC 1 2 4 3 Sensitive Out put Differential amplifier GND The ferromagnetic magnetoresistance element differs from the semiconductor magnetoresistance element and hole element in that it responds only to the magnetic field within the element's surface. It is not sensitive to the magnetic field perpendicular to the element. —2— DM-231 Basic Application Rotation angular detection S 2 N 1 3 Out put Differential amplifier 4 Out put H=14400A/m –90° 0° Handling precautions 1) Most suitable magnetic field intensity When the external magnetic field is at H=14400A/m, rotation angle can be detected most effectively. 231 H Magnetic field angle θ 90° θ Magnetic field angle θ Out put H H>14400A/m H=14400A/m H<14400A/m θ 231 –90° 0° 90° Magnetic field angle θ Whe the external magnetic field H<14400A/m, output voltage shrinks. When the external magnetic field H>14400A/m, the detection angle range shrinks. Whe the external magnetic field H<14400A/m, the detection angle range becomes larger. In regions other than -90° to +90°, the magnetic field combined with the bias magnetic field, shrinks down, which is not advisable. Also, when the range to be detected is smaller than -90° to +90° it is more advantageous to turn to H>14400A/m. 2) External magnetic field direction With regards to the bias magnetic field, usage at other than ±90° should be avoided. That causes a decrease in the combined magnetic field intensity, that is not recommended. H H 231 231 1 1 H —3— H DM-231 Midpoint potential vs. Magnetic field Intensi ty (1) 2.54 Midpoint potential vs. Magnetic field Intensity (2) AAAA AAAA AAAA AAAA AAAA 2.54 H 2.52 GND 231 VA-Midpoint potential (V) VCC=5V 2.50 H 2.48 VA VCC 2.46 4000 0 8000 GND 231 12000 AAAA AAAA AAAA AAAA AAAA H VB-Midpoint potential (V) VA VCC VCC 2.52 GND VB VCC=5V 2.50 H 2.48 VCC 2.46 16000 231 0 H-Magnetic field intensity (Oe) 4000 8000 12000 231 GND VB 16000 H-Magnetic field intensity (Oe) Midpoint potential vs. Magnetic field direction Output voltage vs. Magnetic field intensity 200 VA 2.52 θ H VA 2.50 231 VCC VCC=5V H=14400A/m 2.48 GND VB Vo-Output voltage (mVp-p) VA, VB-Midpoint potential (V) 2.54 150 100 H VA VCC 50 VB 231 H: Peak intensity of AC magnetic field VCC=5V 2.46 –90 0 –45 45 90 0 θ-Magnetic field direction (deg) Temperature characteristics 200 700 150 600 VO 100 500 H=14400A/m AC Magnetic field VCC=5V 50 —20 0 20 40 60 RT -Total resistance (Ω) Vo-Output voltage (mVp-p) 800 RT 400 80 Ta-Ambient temperature (°C) —4— GND VB 4000 8000 12000 16000 H-Magnetic field intensity (Oe) DM-231 Unit : mm 0.4 0.15 2.54 SONY CODE 0.25 2.5 MAX M-118 EIAJ CODE JEDEC CODE PACKAGE WEIGHT —5— 0.2g 22.0 ± 0.3 + 0.4 4.5 – 0.1 M-118 4.5 ± 0.1 Package Outline