ASHEP0001

133 Aviation Blvd., Suite 101
Santa Rosa, CA 95403-1084 USA
707-566-2260 main
707-566-2261 fax
www.pnicorp.com
Transitioning from A-Series To F-Series Sensors
PNI’s new Sen-XY-f and Sen-Z-f geomagnetic sensors (F-series sensors) represent a significant
improvement in magnetic sensing performance when compared with alternative magnetic
sensors, including PNI’s legacy Sen-XY and Sen-Z sensors (A-series sensors). The new F-series
sensors provide lower noise, lower power consumption, improved gain and resolution, and
reduced unit-to-unit variability. This document reviews the differences between the sensors, and
how to implement F-series sensors into an existing system that currently uses A-series sensors.
Specification Differences
The table below consolidates performance specifications for both sensors. Specifications
assume the sensor is mated to PNI’s 3D MagIC ASIC.
Table 1: Specification Differences
Parameter
Units
A-Series
F-Series
H
400-600 typ.
500-600 typ.
30
same
%/C
0.4 typ.
same
Operating Voltage Range
V
1.6 to 3.3
same
Field Measurement Range*
T
-1100 to +1100
-800 to +800
Gain @ 200 cycle counts
(Resolution = 1/Gain)
counts/ T
45 @ 3.3V
45 @ 3.3V (same)
55 @ 2.8V
Noise @ 200 cycle counts
nT
35
30
% of 200 T
0.6 typ., 1.0 max
same
mA
0.3 @ 3.3V
0.20 @ 2.8V
0.25 @ 3.3V
Linear Regime
33 + (V-1.6)*35
[1.6V to 2.6V]
60 + (V-1.6)*67
[1.6 V to 2.2V]
Fixed Regime
68
[2.6V to 3.3V]
100
[2.2V to 3.3V]
33
same
kHz
185
195
C
-40 to +85
same
Inductance
DC Resistance @ 25C 15C
Resistance vs. Temperature
Linearity - best fit over 200 T
Average Current per Axis 35 Hz & 200 Cycle Counts
Recommended
Bias Resistance
External Timing Resistor (REXT)
Circuit Oscillation Frequency
Operating Temperature
*The F-Series field measurement range can be extended if necessary, but involves trade-offs.
Contact PNI if you require >±800 T range.
PNI Sensor Corp.
Page 1 of 2
August 21, 2010
133 Aviation Blvd., Suite 101
Santa Rosa, CA 95403-1084 USA
707-566-2260 main
707-566-2261 fax
www.pnicorp.com
Mechanical Differences
The legacy Sen-XY and new Sen-XY-f have the same footprint and overall mechanical
dimensions. And the new Sen-XY-f can be accommodated by the Sen-XY’s pad layout.
Note that the RM-3000-f & RM2000-f User Manual recommends a different pad layout than
the RM-3000 & RM2000 User Manual. The reason for the change is PNI has found the new
layout makes rework easier. This is true for either version of the sensor. The legacy layout
recommendation, however, is still acceptable and allows for the smallest footprint.
The new Sen-Z-f is available in two versions, a backward-compatible version, pn 13070, and
a physically more robust version, pn 13101. The 13070 has the same footprint ,dimensions,
and recommend pad layout as the legacy Sen-Z, pn 12779. The 13101 is taller and has a
larger solder pad area, which results in a much more robust sensor-to-PCB solder joint and
eliminates any need for the Sen-Z shield. Indeed, the Sen-Z shield is uncompatible with the
13101 sensor. Dimensions for the 12779, 13070, 13101, and Sen-Z shield are given below.
For additional information and drawings, see the appropriate user manual.
Table 2: Sen-Z and Sen-Z-f Dimensions
Units
PN 12779
& 13070
PN 13101
Sen-Z Shield
Height
mm
5.75 max
6.35 max
6.10 typ.
Footprint
mm
3x3
3.9 x 3
5.7 x 4.1
Recommended Solder Pad
(allowing for rework)
mm
4.0 x 2.4
5.2 x 1.95
6.5 x 4.0
Parameter
Implementation of F-Series Sensors
If the user wants to implement the new F-Series sensors with minimal effort, then the only
required change is to switch the bias resistors. For most users this means changing the bias
resistor on all their sensors from 68 to 100 , although if the system is operating at <2.6 V
then Table 1 should be consulted. Changing the bias resistors is the one change that
absolutely should be made.
If operating at <3 V, then changing to F-series sensors will somewhat increase the gain of the
system. In this case it may be desirable to reduce the number of cycle counts in software in
order to further decrease power consumption while retaining gain and resolution.
Alternatively, if nothing is changed in software, then the gain and resolution of the system
will improve.
For the Sen-Z-f, the user may decide to use the more robust 13101, rather than the backwardcompatible 13070. In this case, the pad layout should change per the RM-3000-f &
RM2000-f User Manual.
PNI Sensor Corp.
Page 2 of 2
August 21, 2010
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