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3 other layout considerations, 3 magi2c pin-out, 1 general pins – PNI RM3100 Sensor Suite User Manual

Page 20: Avdd and dvdd (pins 4, 14, & 26), Avss and dvss (pins 5 & 19), Other layout considerations, Magi2c pin-out, General pins

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PNI Sensor Corporation

Doc 1017252 r03

RM3100 & RM2100 Sensor Suite User Manual

Page 19 of 45

If an RM3100 Evaluation Board is not available, gradually bring the component

in question closer to one of the sensor coils and observe when the sensor reading

from the MagI2C starts to change.

4.2.3 Other Layout Considerations

Other design considerations include:

To minimize the effect of gradients in the magnetic field, position the sensor coils

as close to each other as possible.

To reduce coupling to and from other signals, keep the two traces from the

MagI2C to each sensor coil as close as possible to each other. PNI recommends

locating the MagI2C within 10 cm from the sensor coils.

Keep capacitors, especially tantalum capacitors, far away from the sensor coils.

4.3 MagI2C Pin-Out

The MagI2C’s pin-out is summarized on the following page in Table 4-1. Pin numbers run

counterclockwise, when looking from the top, starting at the Pin 1 designator as shown in

Figure 3-7.

4.3.1 General Pins

AVDD and DVDD (pins 4, 14, & 26)

AVDD and DVDD should be tied to the analog and digital supply voltages,

respectively. The recommend voltages are defined in Table 3-5, and the maximum

voltages are given in Table 3-4. DVDD must be on whenever AVDD is on, so

DVDD should either be brought up first or at precisely the same time as AVDD.

AVDD can be turned off when not making a measurement to conserve power, since

all other operations are supported with DVDD. Under this condition, register values

will be retained as long as DVDD is powered. Also, AVDD must be within 0.1 V of

DVDD when AVDD is on.

AVSS and DVSS (pins 5 & 19)

AVSS and DVSS should be tied to the analog and digital ground, respectively.

Assuming the ground plane is clean, they may share a common ground.

Alternatively, they may have their own ground planes if this is more convenient.

DVSS and AVSS should be within 0.1 V of each other.