- 您现在的位置：买卖IC网 > Sheet目录478 > MMA6556KW (Freescale Semiconductor)IC ACCELEROMETER X AXIS 16QFN
3.6
Self Test Interface
When self test is enabled, the self test interface applies a voltage to the g-cell, causing a deflection of the proof mass. Once
enabled, offset cancellation is suspended and the deflection results in an acceleration which is superimposed upon the input ac-
celeration.
The resulting acceleration readings can be compared either against absolute limits, or the values stored in the Self Test De-
flection Registers (Reference Section 3.1.2 ). The self test interface is controlled through SPI write operations to the DEVCFG
register described in Section 3.1.7 only if the ENDINIT bit in the DEVCFG register is cleared. A diagram of the self test interface
is shown in Figure 10 .
SELF-TEST
VOLTAGE
GENERATOR
g-CELL
ENDINIT
ST
ENDINIT
Figure 10. Self Test Interface
3.6.1
Raw Self Test Deflection Verification
The raw self test deflection can be directly verified against raw self test limits listed in Section 2.4 .
3.6.2
Delta Self Test Deflection Verification
Δ ST ACCMINLIMIT = FLOOR ? ? Δ ST MIN + ------------------------------------------ × [ Δ ST MAX – Δ ST MIN ] ? × ( 1 – Δ ST ACC )
Δ ST ACCMAXLIMIT = CEIL ? ? ? Δ ST MIN + ------------------------------------------ × [ Δ ST MAX – Δ ST MIN ] ? ? × ( 1 + Δ ST ACC )
The raw self test deflection can be verified against the ambient temperature self test deflection value recorded at the time the
device was produced. The production self test deflection is stored in the STDEFL register such that the minimum stored value
(0x00) is equivalent to Δ ST MIN , and the maximum stored value (0xFF) is equivalent to Δ ST MAX . The Delta Self Test Deflection
limits can then be determined by the following equations:
Δ STDEFLx CNTS
? 255 ?
Δ STDEFLx CNTS
255
where:
Δ ST ACC
Δ STDEFLx CNTS
Δ ST MIN
Δ ST MAX
The accuracy of the self test deflection relative to the stored deflection as specified in Section 2.4 .
The value stored in the STDEFL register.
The minimum self test deflection at 25C as specified in Section 2.4 .
The maximum self test deflection at 25C as specified in Section 2.4 .
MMA655x
Sensor
Freescale Semiconductor, Inc.
23
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
MMA6826AKW
IC ACCELEROMETER XY AXIS 16QFN
MMA6854KW
IC ACCELEROMETER X AXIS 16QFN
MMA7331LR2
ACCELEROMETER 4G XYZ ENH 14-LGA
MMA8451QT
IC ACCELEROMETER 3AXIS 16QFN
MMA8452QR1
IC ACCELER 2G/4G/8G 3AXIS 16QFN
MMA8453QR1
IC ACCELER 2G/4G/8G 3AXIS 16QFN
MMBF0201NLT1
MOSFET N-CH 20V 300MA SOT-23
MMBF170-7
MOSFET N-CH 60V 500MA SOT23-3
相关代理商/技术参数
MMA6556KWR2
功能描述:加速计 - 板上安装 X-AXIS 120G RoHS:否 制造商:Murata 传感轴:Double 加速:12 g 灵敏度: 封装 / 箱体: 输出类型:Analog 数字输出 - 位数:11 bit 电源电压-最大:5.25 V 电源电压-最小:4.75 V 电源电流:4 mA 最大工作温度:+ 125 C 最小工作温度:- 40 C
MMA65XX
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Dual-Axis SPI Inertial Sensor
MMA6700AEGR2
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
MMA6700EG
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
MMA6700EGR2
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
MMA6701AEGR2
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
MMA6701EG
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
MMA6701EGR2
制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:High Accuracy Low g Inertial Sensor MEMS Sensing, State Machine ASIC
