Datasheet DM-231 Datasheet (Sony)

Magnetoresistance Element

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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.

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)

DM-231

M-118 (Plastic)

Applications

• Non-contact angle of rotation detection.

• Contactless potentiometer.

Absolute Maximum Ratings (Ta=25 °C)

• Supply voltage VCC 10 V

• Storage temperature Tstg –30 to +100 °C

Recommended Operating Conditions

• Supply voltage VCC 5V

•Operating temperature Topr –20 to + 75 °C

Electrical Characteristics Ta=25 °C

Item Symbol Condition Min. Typ. Max. Unit
Output voltage
Midpoint potential

Midpoint potential
difference/Output voltage

Total resistance

VO

VA, VB

|VA-VB|

VO
RT

VCC=5 V , H=14400 A/m (Peak)
AC magnetic field θ =0 °
VCC=5 V , H=0 A/m

VCC=5 V , H=0 A/m
H=14400 A/m (Peak)

AC magnetic field θ =0 °

150

2.475

500 650

2.525
15

800

mVp-p

V

%

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

Equivalent Circuit

DM-231

1

CC

V

Basic Performance

1) Operation principle

External magnetic field H

Synthetic
magnetic field (a)

Bias magnetic field
H=14400A/m

VA

3

GND

RD

RC

4

B

V

RA

2

RB

Various resistances change according to the direction of
the combnied bias and external magnetic field.

1

¡) When the direction of the synthetic magnetic field is (a),

RA,RC : Maximum resistance
RB,RD : Minimum resistance

RA

2

R

B

3

RD

¡¡) When the direction of the synthetic magnetic field is (b),

4

RA,RC : Minimum resistance

RC

External magnetic field H

RB,RD : Maximum resistance

Synthetic magnetic field (b)

∗ Device internal structure

(Back of mark face)

Bias magnetic field

3
4

2

1

2) Power supply pin and output pin 3) Sensitivity direction

2
1

1

231

2

4

Differential amplifier

3
4

V

CC

Out put

The ferromagnetic magnetoresistance element differs
from the semiconductor magnetoresistance element and
hole element in that it responds only to the magnetic

Non-Sensitive

field within the element's surface. It is not sensitive to

3

GND

the magnetic field perpendicular to the element.

Sensitive

—2—

Basic Application

Rotation angular detection

3

DM-231

S

N

4

2

1

Out put

Differential amplifier

Out put

–90°

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.

H=14400A/m

0°

90°

θ

231

Magnetic field
angle θ

H

–90°

231

Out put

H

θ

Magnetic field angle θ

H>14400A/m

H=14400A/m
H<14400A/m

90°

0°

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.

HH

231 231

11

HH

—3—

DM-231

Midpoint potential vs. Magnetic field Intensi ty (1)

2.54

A

V

2.52

VCC

2.50

2.48

A

V

VCC

2.46

-Midpoint potential (V)

A

V

0

4000 8000 12000 16000

H-Magnetic field intensity (Oe)

Midpoint potential vs. Magnetic field direction

2.54

H

231

VCC=5V

H

231

GND

GND

Midpoint potential vs. Magnetic field Intensity (2)

2.54

2.52

VCC

2.50

-Midpoint potential (V)

B

2.48

V

VCC

2.46

0

4000 8000 12000 16000

H-Magnetic field intensity (Oe)

Output voltage vs. Magnetic field intensity

200

H

231

VCC=5V

H

231

GND

V

B

GND

B

V

2.52

2.50

-Midpoint potential (V)

B

2.48

, V

A

V

2.46

–45–90

θ-Magnetic field direction (deg)

Temperature characteristics

200

150

VA

H

θ

VA

V

231

CC

GND
VB

VCC=5V
H=14400A/m

VB

0

45 90

150

100

Vo-Output voltage (mVp-p)

50

0

H: Peak intensity of AC magnetic field

4000 8000 12000 16000

VA

VCC

VCC=5V

H

231

GND

B

V

H-Magnetic field intensity (Oe)

800

T

R

700

600

VO

100

Vo-Output voltage (mVp-p)

50

—20

0204060

Ta-Ambient temperature (°C)

H=14400A/m
AC Magnetic field
VCC=5V

80

500

400

-Total resistance (Ω)

T

R

—4—

Package Outline Unit : mm

M-118

4.5 ± 0.1

+ 0.4

4.5 – 0.1

DM-231

22.0 ± 0.3

0.4

SONY CODE
EIAJ CODE
JEDEC CODE

2.54

M-118

2.5 MAX

PACKAGE WEIGHT

0.250.15

0.2g

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