Dual Axis Accelerometer
Evaluation Board
ADXL213EB
Rev. 0
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GENERAL DESCRIPTION
The ADXL213EB is a simple evaluation board that allows quick
evaluation of the performance of the ADXL213 dual axis ±1.2 g
accelerometer. The user needs to add only three additional
through-hole passive components, depending on the bandwidth
required in the application. The ADXL213EB has a 5-pin
0.1 inch spaced header for access to all power and signal lines
that the user can attach to a prototyping board (breadboard) or
wire using a standard plug. Two holes are provided for
mechanical attachment of the ADXL213EB to the application.
CIRCUIT DESCRIPTION
The schematic and parts list of the ADXL213EB are shown in
Figure 1 and Table 1, respectively. The minimal application
requires at least one resistor (R
SET
) added to the board to set the
PWM period (T2). Analog bandwidth can be set by adding
capacitors C2 and C3. See the ADXL213 data sheet for a
complete description of the operation of the accelerometer.
The part layout of the ADXL213EB is shown in Figure 2. The
ADXL213EB has two factory-installed 2200 pF capacitors (C1
and C4) at X
FILT
and Y
FILT
to satisfy the minimum filter capacitor
specification for the ADXL213. Many applications require a
narrower bandwidth (and lower noise), in which case the user
can add a through-hole capacitor in parallel in the space
provided at C2 and C3, respectively. When calculating the
capacitance required to achieve the desired analog bandwidth,
do not forget to subtract the 2200 pF already on the PCB.
The pin function descriptions for the ADXL213EB are listed in
Table 2.
SETTING THE PERIOD OF THE DUTY CYCLE
MODULATOR
The DCM period is set by R
SET
. Choose a value between 100 kΩ
and 2 MΩ. See Table 3 for typical R
SET
values.
ADXL213
COMMON
C4
2200pF
R
SET
ADDED
BY USER
C3
ADDED
BY USER
C5
0.47µF
Y
OUT
PIN 1
X
OUT
V
DD
ST
04838-0-001
A
D
C
E
B
C1
2200pF
C2
ADDED
BY USER
Figure 1. ADXL213EB Schematic
