LIS3L02AQ

LIS3L02AQ INERTIAL SENSOR: 3Axis - 2g/6g LINEAR ACCELEROMETER 1 ■ ■ ■ ■ FEATURES 2.4V TO 3.6V SINGLE SUPPLY OPERATION 0.5mg RESOLUTION OVER 100Hz BW 2g/6g USER SELECTABLE FULL-SCALE OUTPUT VOLTAGE, OFFSET AND SENSITIVITY RATIOMETRIC TO THE SUPPLY VOLTAGE FACTORY TRIMMED DEVICE SENSITIVITY AND OFFSET EMBEDDED SELF TEST HIGH SHOCK SURVIVABILITY Figure 1. Package QFN-44 Table 1. Order Codes Part Number LIS3L02AQ Package QFN-44 ■ ■ ■ 2 DESCRIPTION The LIS3L02AQ is a low-power three-axis linear accelerometer that includes a sensing element and an IC interface able to take the information from the sensing element and to provide an analog signal to the external world. The sensing element, capable to detect the acceleration, is manufactured using a dedicated process called THELMA (Thick Epi-Poly Layer for Microactuators and Accelerometers) developed by ST to produce inertial sensors and actuators in silicon. The IC interface instead is manufactured using a CMOS process that allows high level of integration to design a dedicated circuit which is trimmed to better match the sensing element characteristics. Figure 2. Block Diagram S1X S1Y S1Z The LIS3L02AQ has a user selectable full scale of 2g, 6g and it is capable of measuring accelerations over a maximum bandwidth of 4.0 KHz for the X and Y axis and 2.5KHz for the Z axis. The device bandwidth may be reduced by using external capacitances. A self-test capability allows the user to check the functioning of the system. The LIS3L02AQ is available in plastic SMD package and it is specified over a temperature range extending from -40°C to +85°C. The LIS3L02AQ belongs to a family of products suitable for a variety of applications: – Motion activated functions in mobile terminals – Gaming and Virtual Reality input devices – Free-fall detection and Data protection – Antitheft systems and Inertial Navigation – Appliance Control and Robotics Routx CHARGE AMPLIFIER S/H Voutx rot S2Z S2Y S2X MUX DEMUX Routy S/H Vouty Routz S/H Voutz VOLTAGE & CURRENT REFERENCE TRIMMING CIRCUIT & TEST INTERFACE CLOCK & PHASE GENERATOR November 2004 Rev. 4 1/9 LIS3L02AQ Table 2. Pin Description N° 1 to 3 4 5 6 7 8 9-13 14 15 16 17-18 19 20 21 22-23 24-25 26 27 28 29-44 Pin NC GND Vdd Vouty ST Voutx NC PD Voutz FS Reserved NC Reserved NC Reserved NC Reserved Reserved Reserved NC Internally not connected 0V supply Power supply Output Voltage Self Test (Logic 0: normal mode; Logic 1: Self-test) Output Voltage Internally not connected Power Down (Logic 0: normal mode; Logic 1: Power-Down mode) Output Voltage Full Scale selection (Logic 0: 2g Full-scale; Logic 1: 6g Full-scale) Leave unconnected Internally not connected Leave unconnected Internally not connected Leave unconnected Internally not connected Connect to Vdd or GND Leave unconnected or connect to Vdd Leave unconnected or connect to GND Internally not connected Function Figure 3. Pin Connection (Top view) NC NC NC NC NC NC NC NC NC NC NC Z 1 Y NC NC NC GND Vdd NC NC NC NC NC X Vouty ST Voutx NC NC NC LIS3L02AQ Reserved Reserved Reserved NC NC Reserved FS NC NC Voutz Reserved Reserved Reserved Reserved NC PD 2/9 Reserved DIRECTION OF THE DETECTABLE ACCELERATIONS LIS3L02AQ Table 3. Electrical Characteristics (Temperature range -40°C to +85°C) All the parameters are specified @ Vdd =3.3V, T=25°C unless otherwise noted Symbol Vdd Idd Parameter Supply voltage Supply current mean value PD pin connected to GND rms value PD pin connected to Vdd T = 25°C Delta from +25°C FS pin connected to GND FS pin connected to Vdd So Sensitivity2 Full-scale = 2g Full-scale = 6g SoDr NL Sensitivity drift Vs temperature Non Linearity4 Delta from +25°C Best fit straight line Full-scale = 2g X, Y axis Best fit straight line; Full-scale = 2g Z axis CrossAx Cross-Axis5 fuc Sensing Element Resonant Frequency6 Acceleration noise density X, Y axis Z axis Vdd=3.3V; Full-scale = 2g T = 25°C Vdd=3.3V Full-scale = 2g X axis T = 25°C Vdd=3.3V Full-scale = 2g Y axis T = 25°C Vdd=3.3V Full-scale = 2g Z axis -20 3.2 1.8 ±1.8 ±5.4 Vdd/5–10% Vdd/15–10% Vdd/2-10% Test Condition Min. 2.4 Typ.1 3.3 0.85 Max. 3.6 1.5 Unit V mA IddPdn Supply current in Power Down Mode Zero-g level2 Zero-g level Vs temperature Acceleration range3 2 5 µA Voff OffDr Ar Vdd/2 ±1.5 ±2.0 ±6.0 Vdd/5 Vdd/15 ±0.01 ±0.3 Vdd/2+10% V mg/°C g g Vdd/5+10% Vdd/15+10% V/g V/g %/°C ±1.5 % FS ±0.6 ±2 % FS ±2 4.0 2.5 50 ±4 4.8 3.2 % KHz KHz µg/ Hz an Vt Self test output voltage delta change7,8,9 -40 mV 20 40 mV 20 50 mV 3/9 LIS3L02AQ Table 3. Electrical Characteristics (continued) (Temperature range -40°C to +85°C) All the parameters are specified @ Vdd =3.3V, T=25°C unless otherwise noted Symbol Vst Parameter Self test input Test Condition Logic 0 level Logic 1 level Rout Cload Ton Output impedance Capacitive load drive 10 Min. 0 2.2 80 320 Typ.1 Max. 0.8 Vdd Unit V V 110 140 kΩ pF Turn-On Time at exit from Power Down mode Cload in µF 550*Cload +0.3 ms Notes: 1. Typical specifications are not guaranteed 2. Offset and sensitivity are essentially ratiometric to supply voltage 3. Guaranteed by wafer level test and measurement of initial offset and sensitivity 4. Guaranteed by design through measurements done up to 1g 5. Contribution to the measuring output of the inclination/acceleration along the perpendicular axis 6. Guaranteed by design 7. Self test “output voltage delta change” is defined as Vout(Vst=Logic1)-Vout(Vst=Logic0) 8. Self test “output voltage delta change” varies cubically with supply voltage 9. When full-scale is set to 6g, self-test “output delta change” is one third of the specified value 10.Bandwidth=1/(2*π*110KΩ*Cload) ABSOLUTE MAXIMUM RATING Stresses above those listed as “absolute maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Table 4. Absolute Maximum Rating Symbol Vdd Vin APOW Supply voltage Input voltage on any control pin (FS, PD, ST) Acceleration (Any axis, Powered, Vdd=3.3V) Ratings Maximum Value -0.3 to 7 -0.3 to Vdd +0.3 3000g for 0.5 ms 10000g for 0.1 ms AUNP Acceleration (Any axis, Unpowered) 3000g for 0.5 ms 10000g for 0.1 ms TOP TSTG ESD Operating Temperature Range Storage Temperature Range Electrostatic discharge protection -40 to +85 -40 to +105 2KV HBM °C °C Unit V V 4/9 LIS3L02AQ 3 FUNCTIONALITY The LIS3L02AQ is a low-cost, low-power, analog output three-axis linear accelerometer packaged in QFN package. The complete device includes a sensing element and an IC interface able to take the information from the sensing element and to provide an analog signal to the external world. 3.1 Sensing element The THELMA process is utilized to create a surface micro-machined accelerometer. The technology allows to carry out suspended silicon structures which are attached to the substrate in a few points called anchors and free to move on a plane parallel to the substrate itself. To be compatible with the traditional packaging techniques a cap is placed on top of the sensing element to avoid blocking the moving parts during the molding phase. The equivalent circuit for the sensing element is shown in the figure below; when a linear acceleration is applied, the proof mass displaces from its nominal position, causing an imbalance in the capacitive half-bridge. This imbalance is measured using charge integration in response to a voltage pulse applied to the sense capacitor. Figure 4. Equivalent electrical circuit Cps1 Rs1 S1x Cs1x Cpr Rr Cs2x S2x Cps2 Cps1 Rs2 Rs1 S1y Cs1y Cpr Rr rot Cs2y S2y Cps2 Rs2 Cps1 Rs1 S1z Cs1z Cpr Rr Cs2z S2z Cps2 Rs2 5/9 LIS3L02AQ The nominal value of the capacitors, at steady state, is few pF and when an acceleration is applied the maximum variation of the capacitive load is few hundredths of pF. 3.2 IC Interface The complete signal processing uses a fully differential structure, while the final stage converts the differential signal into a single-ended one to be compatible with the external world. The first stage is a low-noise capacitive amplifier that implements a Correlated Double Sampling (CDS) at its output to cancel the offset and the 1/f noise. The produced signal is then sent to three different S&Hs, one for each channel, and made available to the outside. The low noise input amplifier operates at 200 kHz while the three S&Hs operate at a sampling frequency of 66 kHz. This allows a large oversampling ratio, which leads to in-band noise reduction and to an accurate output waveform. All the analog parameters (output offset voltage and sensitivity) are ratiometric to the voltage supply. Increasing or decreasing the voltage supply, the sensitivity and the offset will increase or decrease linearly. The feature provides the cancellation of the error related to the voltage supply along an analog to digital conversion chain. 3.3 Factory calibration The IC interface is factory calibrated to provide to the final user a device ready to operate. The trimming values are stored inside the device by a non volatile structure. Any time the device is turned on, the trimming parameters are downloaded into the registers to be employed during the normal operation thus allowing the final user to employ the device without any need for further calibration. 6/9 LIS3L02AQ 4 PACKAGE INFORMATION Figure 5. QFN-44 Mechanical Data & Package Dimensions mm DIM. MIN. A A1 b D E e J K L P 5.04 5.04 0.38 0.48 45 REF 1.70 0.19 0.20 0.25 7.0 7.0 0.50 5.24 5.24 0.58 0.198 0.198 0.015 0.019 45 REF TYP. 1.80 MAX. 1.90 0.21 0.30 MIN. 0.067 0.007 0.008 0.01 0.276 0.276 0.020 0.206 0.206 0.023 TYP. 0.071 MAX. 0.075 0.008 0.012 inch OUTLINE AND MECHANICAL DATA QFN-44 (7x7x1.8mm) Quad Flat Package No lead M G M N 34 44 44 1 33 1 DETAIL "N" 23 11 22 12 DETAIL G SEATING PLANE 7/9 LIS3L02AQ Table 5. Revision History Date January 2004 February 2004 November 2004 November 2004 Revision 1 2 3 4 First Issue Values of some parameters has been changed in Electrical characteristics table. Modified/added some values in the table 2 Electrical characteristics. Corrected few typo errors. Description of Changes 8/9 LIS3L02AQ Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. 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