ST意法半导体
直播中

周润艺

7年用户 200经验值
私信 关注
[问答]

LIS3DH噪声特性的疑问

亲爱的大家,


我使用配置1.25 kHz带宽(ODR)和高分辨率(12位)的LIS3DH,满量程范围为+/- 2g。我对这个频率应该有的噪音有疑问:

数据表给出的加速度噪声密度为220 ug / sqrt(Hz)。我在飞思卡尔pdf中发现了以下注释:

''当此值(噪声密度)乘以测量带宽的平方根时,此结果是RMS加速度噪声
标称VDD和温度下的传感器。低于此值的加速度将无法解析。 “”

在我的情况下,该计算给出峰值到22mg(约5位)的峰值噪声。这个推理是否正确?

谢谢你的帮助。

以上来自于谷歌翻译


以下为原文




Dear all,


I am using the LIS3DH configured with 1.25 kHz bandwith (ODR) and high resolution (12bits), full scale range of +/- 2g. I have a question regarding the noise I should expect at this frequency :

The datasheet gives an Acceleration noise density of 220 ug/sqrt(Hz). I found in a Freescale pdf the following note :

'' When this value (noise density) is multiplied by the square root of the measurement bandwidth, this result is the RMS acceleration noise of the
sensor at nominal VDD and temperature. Accelerations below this value will not be resolvable.  ''

In my case this calculation gives a peak to peak noise of 22 mg (about 5 bits). Is this reasoning correct ?

Thanks for your help.

回帖(1)

周润艺

2018-9-30 10:50:49
你好,
 
 
 有人已经描述了LIS3DH加速度计的噪音吗?数据表中唯一可用的信息是噪声密度为220 ug / sqrt(Hz)。这是白噪声的特点吗?
 
 BW为625 Hz的结果如下所示

 
 RMS噪声的实际结果接近220 ug / sqrt(625),然而在FFT图中观察到的峰具有更高的幅度。
 
 让我知道你的意见。这是LIS3DH的固有噪声特性吗?

以上来自于谷歌翻译


以下为原文





Hello,


Did somebody already characterize the noise of the LIS3DH accelerometer ? The only information available in datasheet isthe noise density of 220 ug/sqrt(Hz). Is this a white noise characteristics ?

The results obtained with a BW of 625 Hz is as shown in the
:

Pratical results of RMS noise are close to 220 ug/sqrt(625), however the peak obseved in the FFT graph have higer amplitude.

Let me know your opinion. Is this the intrinsic noise characteristics of the LIS3DH ?
举报

更多回帖

发帖
×
20
完善资料,
赚取积分