Dual Axis Accelerometer Evaluation Board ADXL213EB 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. The part layout of the ADXL213EB is shown in Figure 2. The ADXL213EB has two factory-installed 2200 pF capacitors (C1 and C4) at XFILT and YFILT 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. CIRCUIT DESCRIPTION The pin function descriptions for the ADXL213EB are listed in Table 2. 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 (RSET) 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. SETTING THE PERIOD OF THE DUTY CYCLE MODULATOR The DCM period is set by RSET. Choose a value between 100 kΩ and 2 MΩ. See Table 3 for typical RSET values. PIN 1 RSET ADDED BY USER C5 0.47µF C3 ADDED BY USER C1 C4 2200pF 2200pF VDD D XOUT C YOUT E COMMON B ST C2 ADDED BY USER 04838-0-001 ADXL213 A Figure 1. ADXL213EB Schematic Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved. ADXL213EB Table 1. ADXL213EB Parts List Reference C1 C2 C3 C4 J1 R1 U1 Value 2200 pF/25 V Added by user Added by user 2200 pF/25 V Connector Added by user ADXL213 Function XFILT. Sets X axis analog bandwidth along with C2. XFILT. Sets X axis analog bandwidth along with C1. YFILT. Sets Y axis analog bandwidth along with C4. YFILT. Sets Y axis analog bandwidth along with C3. All power and signal connection through J1. RSET. Sets the PWM period (T2). Dual axis ±2 g accelerometer. Table 2. ADXL213EB Pin Function Descriptions Pin Reference E B D C A Function Ground Self-Test Input X Axis Duty Cycle Out Y Axis Duty Cycle Out +V Supply (3 VDC to 5.25 VDC) C5 C1 C2 RSET U1 C4 Table 3. DCM Period vs. RSET Value C3 RSET 124 kΩ 248 kΩ 620 kΩ 1.24 MΩ J1 E B D C A 04838-0-002 T2 Period 1 ms 2 ms 5 ms 10 ms Figure 2. ADXL213EB Part Layout (Top View) SETTING THE ADXL213’S BANDWIDTH The ADXL213EB is supplied with the minimum specified XFILT and YFILT values installed. Many applications require a narrower bandwidth to improve noise performance. See Table 4 for typical capacitor values. Table 4. Typical XFILT and YFILT Values vs. Bandwidth and Noise Performance XFILT, YFILT 0.01 µF 0.047 µF 0.1 µF 0.47 µF Bandwidth 500 Hz 100 Hz 50 Hz 10 Hz RMS Noise 4.5 mg 2 mg 1.4 mg 0.6 mg SPECIAL NOTES ON HANDLING The ADXL213EB is not reverse polarity protected. Reversing the +V supply and ground pins causes damage to the ADXL213. Dropping the ADXL213EB on a hard surface can generate several thousand g of acceleration, enough to damage the accelerometer. See the ADXL213 data sheet for information on shock survivability. ORDERING GUIDE Model ADXL213EB © 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04838–0–4/04(0) Rev. 0 | Page 2 of 2 Package Description Evaluation Board