Philips Semiconductors
Magnetoresistive sensors for
magnetic field measurement
General
Two further resistors, RT, are included, as shown in Fig.5. These are for trimming sensor offset down to (almost) zero during the production process.
MLC129
handbook, halfpage
RT |
| RT |
|
4 | 3 | 2 | 1 |
VCC | VO | GND | VO |
Fig.5 Bridge configuration with offset trimmed to zero, by resistors RT.
For some applications however, the MR effect can be used to its best advantage when the sensor output characteristic has been linearized. These applications include:
∙Weak field measurements, such as compass applications and traffic detection;
∙Current measurement; and
∙Rotational speed measurement.
For an explanation of how the characteristic is linearized, please refer to the Section “Further information for advanced users” later in this chapter.
Philips magnetoresistive sensors
Based on the principles described, Philips has a family of basic magnetoresistive sensors. The main characteristics of the KMZ sensors are given in Table 2.
Table 2 Main characteristics of Philips sensors
SENSOR |
| FIELD | VCC | SENSITIVITY | Rbridge | LINEARIZE | APPLICATION |
PACKAGE | RANGE | (mV ⁄ V) | MR | ||||
TYPE |
| (kA/m)(1) | (V) | (kΩ) | EFFECT | EXAMPLES | |
|
|
| (kA ⁄ m) |
|
| ||
KMZ10A | SOT195 | −0.5 to +0.5 | ≤9 | 16.0 | 1.2 | Yes | compass, navigation, metal |
KMZ10A1(2) | SOT195 | −0.05 to +0.05 | ≤9 | 22.0 | 1.3 | Yes | detection, traffic control |
KMZ10B | SOT195 | −2.0 to +2.0 | ≤12 | 4.0 | 2.1 | Yes | current measurement, |
KMZ10C | SOT195 | −7.5 to +7.5 | ≤10 | 1.5 | 1.4 | Yes | angular and linear position, |
|
|
|
|
|
|
| reference mark detection, |
|
|
|
|
|
|
| wheel speed |
|
|
|
|
|
|
|
|
KMZ51 | SO8 | −0.2 to +0.2 | ≤8 | 16.0 | 2.0 | Yes | compass, navigation, metal |
|
|
|
|
|
|
| detection, traffic control |
KMZ52 | SO16 | −0.2 to +0.2 | ≤8 | 16.0 | 2.0 | Yes | |
|
|
|
|
|
|
|
|
Notes
1.In air, 1 kA/m corresponds to 1.25 mT.
2.Data given for operation with switched auxiliary field.
2000 Sep 06 | 5 |
