Features

2.16v to 3.6V power supply voltage

1.8V compatible iOS

lt; 1MW power consumption

± 2g/± 8g dynamic dynamic dynamic dynamic dynamic dynamics Select full marking

I2C/SPI digital output interface

Aerable multi -interrupt generator

Click and double -click recognition

Embedded high -pass filter [ 123]

Instructions

LIS302DL is an ultra -compact low -power product three -axis acceleration meter. It includes a sensor element and IC interface that can provide the measuring acceleration to the outside through the I2C/SPI serial interface. Sensing components can detect acceleration, and use the production inertial craft silicon sensor and actuator developed by special ST companies. The IC interface is the process of allowing the design of special circuits by CMOS to design special circuits in order to better match the characteristics of sensing components. LIS302DL has a user -available function full range of dynamic selection of ± 2g/± 8g with output data rate measuring acceleration 100Hz or 400Hz. The self -test function allows users to check the function of sensors in the final application. This device can be configured to generate inertia wake -up/free fall interrupt signal exceeding the programmable acceleration threshold at least one of the three axes. The timing of the threshold and interrupt generator is dynamically executed by the end user. The LIS302DL can use a grid array bag (TLGA) and its guarantee from -40 ° C to+85 ° C within the extended temperature range.

Mechanical and electrical specifications

Mechanical characteristics

Table 3. Mechanical characteristics (1) (2)

1. The product is defined at 2.5V, which can be used in the range of 2.16V to 3.6V

2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. Unless otherwise explained, all parameters are specified in VDD 2.5V, and t 25 ° C

3. Do not guarantee typical specifications

4. Through chip -level testing and initial offset Verify the sensitivity measurement

5. MSL3 The typical zero G level offset value after pre -processing

6. You can use the built -in high -pass filter to eliminate offset

7. If you use itSTM bit, then the symbol values of all shafts will change

8. Self -inspection output changes with the change of power. Self-inspection output change is defined as output [lsb] (self-inspection positions on ctrl_reg1 1) -Eutment [lsb] (self-inspection of ctrl_reg1 0). 1LSB 4.6G/256, 8 bits, ± 2.3g full marker

9. Due to equipment filtering, when the self -test mode is enabled, the output data after 3/ODR reaches 99%

10.ODR is the output data rate. See Table 4

Electricity

Table 4. Electrical characteristics (1) (2)

1. The product is calibrated from 2.5V, which can be used in the range of 2.16V to 3.6V

2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2.除非另有说明，否则所有参数均在Vdd 2.5V，T 25°C时指定

3.不保证典型规格

4.在这种情况下，可以在Without blocking the communication bus, removing VDD_IO VDD measurement chain disconnection.

5. Filter Dead frequency

6. Time to obtain valid data after exiting the power loss mode

Absolutely maximum rated value

higher than absolutely absolutely absolutely absolutely The stress of the maximum rated value may cause permanent damage to the device. This is just a stress rated value and the functional operation conditions of the device under these pressures are not implicit. Long -term exposure to the highest rating conditions may affect device reliability

Note: The power supply voltage on any pin must not exceed 6.0V

The term

sensitivity

The gain of the sensor describes the sensor, which can be accelerated to it by applying 1G and other methods. Because the sensor can measure the DC acceleration, it is possible to record the output value of the interested axis to the center of the earth, to rotate the sensor by 180 degrees (pointing to the sky) and record the output value again. To do this, apply ± 1g to the sensor. A smaller output value is reduced from it and divorced the results of the result 2 to obtain the actual sensitivity of the sensor. This value changes very little with temperature and changes very little over time. The sensitivity tolerance describes the sensitivity range of a large number of sensors.

Zero gravity level

Zero -G level offset (OFF) describes the deviation of the actual output signal and the ideal value. If there is no acceleration, the output signal is output. The surface of the sensor on the horizontal plane measures 0G on the X -axis and Y axis, and the Z -axis measurement 1G output is ideal in the middle of the sensor dynamic range (the content of the output register is 00h, the data is represented by the complement of 2). In this case, the deviation from the ideal value is called zero gravityShoot. To a certain extent, the offset is the result of the stress of the precision MEMS sensor. Therefore, after installing the sensor on the printing circuit, the offset may change slightly or expose it to the extensive mechanical stress. The offset changes with a small temperature. The zero G level of a single sensor is a stable lifetime. Zero G level tolerance describes the scope of the zero G level of the crowd

The number of sensors.

Self -inspection

Self -inspection allows to check its functions without moving the sensor. The self -inspection function is closed when the self -inspection position programming of the CTRL_Reg1 (control register 1) is 0 . When the self -inspection position of Ctrl_reg1 is programmed as 1 , the driving force is exerted to the sensor to simulate the input acceleration determined. In this case, the sensor output will change at their DC level, which is the full label selected by the sensitivity of the device. When the self -examination activation, the device output level is accelerated by the acceleration and electrostatic test force on the sensor on the sensor. If the output signal changes within the amplitude range specified in Table 3, the sensor operates normally, and the interface chip parameters are standardized within the specified range.

Click and double -click to identify

Click and double -click recognition function to help the creator interface software overload very little. The device can be configured to use special sales in any direction. If the sensor is exposed to a single input stimulation, it will generate a interrupt request interrupt pins (int1 and/or int2) on the inertia. A more advanced function allows the Double -click between the two events when there is a programmable time between the two events. Users can be based on the expected amplitude and stimulus.

Function

LIS302DL is a three -axis acceleration meter packaged in an ultra -compact, low power consumption, digital output in LGA packaging. The entire device includes a sensor element and an integrated circuit interface that can obtain information from the sensing element and pass an I2C/SPI serial interface to the outside world.

Sensing components

Patent process is used to make surface micro -mechanical acceleration meters. This technology can realize several points on the suspended silicon structure substrate called anchor point and can move freely in the direction of sensing. In order to be compatible with traditional packaging technology, a lid is placed on the top of the sensor element to avoid packaging in plastic. When the acceleration is applied to the sensor, the verification quality is from its nominal mass displacement position, resulting in unbalanced capacitors. This imbalance is the measured veins that are measured using charge points to respond to applied to the sensor capacitor. In steady state, the nominal value of the capacitor is a small power factor. When the acceleration is applied, the maximum change of the capacitor load is within the FF range.

IC interface

The entire measurement chain is composed of a low -noise capacitance amplifier to convert the capacitors of the MEMS sensor into analogVoltage, and through the modulus converter. Acceleration data can be accessed through the I2C/SPI interface, so that the device that is particularly suitable for direct interfaces with microcontroller. LIS302DL has a data ready signal (RDY), which indicates that the measured acceleration data is available, so the system of digital synchronous data uses device is simplified. The LIS302DL can also be configured to generate inertia wake -up and free falling body according to the programmatic acceleration event. Freedom and awakening can be at the same time in two different pins.

Factory calibration

The sensitivity (SO) and zero -point level (OFF) of the IC interface were calibrated at the factory. The fine -tuning value is stored inside the device by non -easy -to -sex memory. After the device is turned on at any time, the fine -tuning parameter is downloaded to the register and used in the normal operation period. This allows users to calibrate further use of equipment.

Application prompt

Figure 5. LIS302DL electrical connection

The core of the device is powered through the VDD wire, while the I/O pad is connected through the VDD. Power -coupled counter -coupling capacitors (100 NF ceramics, 10 μF Al) should be as close to the device's pin 6 (general design convention) as much as possible. All voltage and grounding power supply must be existed at the same time so that IC behaviors can be existed at the same time (Reference Figure 5). You can remove the VDD and keep VDD_IO measure the chain of electricity without blocking the communication bus. The function and measuring acceleration data of the device are optional and can access the interface through I2C/SPI. When to use I2C, CS must be tied very high. The functions, thresholds, and timing of the two interrupt pins (int 1 and int 2) may be programmed by the user through the I2C/SPI interface.

Digital interface

The registers embedded in LIS302DL can via I2C and SPI serial interface. The latter can be configured by SW to operate interface mode in 3 or 4 lines. The serial interface is mapped to the same pad. Select/use the I2C interface, the CS line must be tied (that is, connected to the VDD U iO).

I2C serial interface

LIS302DL I2C is a bus from the bus. Using I2C to write the data to the register, it can also be read back. The following table gives relevant I2C terms.

There are two signals related to the I2C bus: serial clock line (SCL) and serial data cable (SDA). The latter is data used to send and receive interfaces. Both lines are connected to the VDD_IO into the LIS302DL through the pull -up resistor. When the bus is free, both lines are very high. The I2C interface conforms to the fast mode (400 kHz) I2C standard and standard mode.

I2C operation

The transaction on the bus was activated by the start (ST) signal. The start -up condition is defined as the high -power conversion of the high -power data line at high electricity lines. After that, this has been transmitted by the main control, and the bus is considered busy. The next byte of the data is transmitted after starting the condition, which contains the address of the machine in the top 7 digits, and the eighth place tells the host whether to receive data from the machine or send data to it. When a address is sent, each device in the system will compare the first 7 digits after a starting condition and its address. If they match, the device thinks they are addressing. The subordinate address (SAD) associated with LIS302DL is 001110XB. You can use SDO PAD to modify the low effective position of the device address. If the SDO PAD is connected to the voltage power supply LSB is #39; 1 #39; (Address 0011101B), otherwise if SDO PAD is connected to the ground, the LSB value is 0 (address 0011100B). This solution allows connecting and processing two different acceleration meters to connect to the same I2C line. There must be confirmation data transmission. The transmitter must release the SDA line during the confirmation pulse. Then the receiver must lower the data cable to maintain a stable low level within the high cycle of the clock pulse. A receiver must be received in every byte of the data. The behavior of I2C embedded in LIS302DL is similar to that from the device that must abide by the agreement. After starting the condition (ST), send a SALVE address. At one time, it is confirmed (SAK) to return. A 8 -bit address: 7LSB represents the actual register address, while the MSB enable address is automatically increasing. If the MSB of the sub -field is 1, the SUB (register address) will automatically increase multiple data read/write. From the machine address, it is completed by a reading/writing position. If the bit is 1 (read), the repeated start (SR) condition must be sent after the two sub -address bytes; if the position is 0 (writing) the host will be sent to the obedience when the direction is unchanged, equipment. Table 10 Explain the composition of SAD+reading/writing position, listing all possible configurations.

The data is transmitted by byte format (data). Each data transmission contains 8 bits. The number of bytes of each transmission of the number is unlimited. Data is first transmitted (MSB) first. If the receiver cannot receive another complete data bytes and other functions before executing, it can maintain the clock line and the SCL is low, forcing the transmitter to enter the waiting country. Only when the receiver is ready to receive another byte and release, the data transmission will continue the data cable. The data cable must be maintained at a high level if the machine receiver does not confirm the address of the machine (that is, it is not receiving, because it is executing some real -time functions). Then the host can stop the transmission. A transition from low to high on the SDA line is defined as stop conditions when SCL line is high. every timeData transmission must end due to the suspension (SP) conditions. In order to read multiple bytes, it is necessary to assert the highest effective position of the sub -address field. In other words, SUB (7) must be equal to 1, and Sub (6-0) indicates the address of the first register to be read. In the communication format provided, Mak is the Lord's confirmation, and NMAK is the NO master confirmed.

SPI bus interface

LIS302DL SPI is the bus from the bus. SPI allows writing and reading devices. The serial interface interacts with the outside world through 4 lines: CS, SPC, SDI and SDO.

CS is the serial port enabled and controlled by the SPI host. From the beginning, it was transmitted very low and returned to the high position at the end. SPC is controlled by the serial port clock by the SPI host. When CS is high (no transmission), the high level stops. SDI and SDO are the input and output of serial data, respectively. These cables are the decline of the SPC and should be captured at the rising edge of the SPC. Reading registers and writing register commands are multiple of 8 clock pulses or in multiple bytes read/write. The duration is the edge of the SPC between the time between the two declines. The first (digit 0) starting the first digit (digit 15, bit 23, ...) at the end of the SPC at the end of the SPC at the end of the SPC. Bit 0: RW bit. At 0, the data di (7: 0) is written into the device. When it is 1, the data is (7: 0) read from the device. In the latter case, the chip will drive SDO at the beginning of the eighth place.

bit 1: MS bit. When 0, the address will remain unchanged in multiple reading/writing commands. When it is 1, the address will automatically increase in multiple read/write commands.

bit 2-7: Address AD (5: 0). This is the address field of the index register.

bit 8-15: Data DI (7: 0) (writing mode). This is the first data that will write to the device (MSB)).

bit 8-16: Data do (7: 0) (read mode). This is the first data read from the device (MSB)).

In multiple reading/writing commands, 8 clock cycle blocks will be added. When the MS bit is 0, the address used to read/write data is kept the same for each block. When the MS bit is 1, the address of the read/write data is increasing in each block. The functions and behaviors of SDI and SDO remain unchanged.