MA120GQ-Z Datasheet, PDF (6/14 Pages) MPS Industries, Inc. – Angular Sensor for 3-Phase Brushless Motor Commutation

MA120
Angular Sensor for 3-Phase Brushless Motor
Commutation
5. Sensor – Magnet Mounting
The sensitive volume of the MA120 is confined in a
region less than 100 µm wide and consists of multiple
integrated Hall devices. This volume is located, with a
precision of 50 m in the center of the QFN package,
both horizontally and vertically. The sensor detects the
angle of the magnetic field projected in a plane parallel
to the package upper surface. It means that the only
magnetic field that matters is the in-plane component
(X and Y components) in the package middle point
This detection mode gives flexibility for the magnet
size: all the sensor needs is that the magnetic vector
lies essentially within the sensor plane and that its
amplitude is comprised between 50 and 200 mT. Note
that the MA120 does work with smaller than 50 mT
fields, but the linearity and resolution performance may
deviate from the specifications (see Table 2).
Figure 4: End-of-Shaft Mounting
6. Power Supply Decoupling
For most applications, a single 100 nF bypass capacitor
placed close to the supply pins sufficiently decouples
the MA120 from noise of the power supply. If better
decoupling is required, a larger capacitor (10 µF) can
be added in parallel with the 100 nF, and/or a resistor
(10 ) can be added between the supply line and the
capacitor node.
In any case, make sure that the connection between the
MA120 ground and the power supply ground has low
impedance, in order to avoid noise transmitted from the
ground. VFLASH needs to be supplied only when
flashing the memory. Otherwise the VFLASH pin can
remain unconnected or grounded (see Figure 5).
Figure 5: Connection for Supply Decoupling
Monolithic Power Systems, Inc. | Gland, Switzerland | Tel: [phone] | [e-mail] | www.sensimatech.com
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Reserved. MA700 Rev 1.0 September 2014
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