PNI RM3100 Sensor Suite - Manual (Page 20)

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.