- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄359176 > MMA2301 (飛思卡爾半導(dǎo)體(中國(guó))有限公司) Surface Mount Micromachined Accelerometer PDF資料下載
參數(shù)資料
| 型號(hào)： | MMA2301 |
| 廠商： | 飛思卡爾半導(dǎo)體(中國(guó))有限公司 |
| 英文描述： | Surface Mount Micromachined Accelerometer |
| 中文描述： | 表面貼裝微加速度計(jì) |
| 文件頁(yè)數(shù)： | 4/10頁(yè) |
| 文件大小： | 275K |
| 代理商： | MMA2301 |
Sensors
4
Freescale Semiconductor
MMA2301D
PRINCIPLE OF OPERATION
The Freescale Semiconductor, Inc. accelerometer is a
surface-micromachined integrated-circuit accelerometer.
The device consists of a surface micromachined
capacitive sensing cell (g-cell) and a CMOS signal
conditioning ASIC contained in a single integrated circuit
package. The sensing element is sealed hermetically at the
wafer level using a bulk micromachined
cap
wafer.
The g-cell is a mechanical structure formed from
semiconductor materials (polysilicon) using semiconductor
processes (masking and etching). It can be modeled as a set
of beams attached to a movable central mass that move
between fixed beams. The movable beams can be deflected
from their rest position by subjecting the system to an
acceleration(
Figure 3
).
As the beams attached to the central mass move, the
distance from them to the fixed beams on one side will
increase by the same amount that the distance to the fixed
beams on the other side decreases. The change in distance
is a measure of acceleration.
The g-cell plates form two back-to-back capacitors
(
Figure 3
). As the central mass moves with acceleration, the
distance between the beams change and each capacitor's
value will change, (C = NA
ε
/D). Where A is the area of the
facing side of the beam,
ε
is the dielectric constant, D is the
distance between the beams, and N is the number of beams.
The CMOS ASIC uses switched capacitor techniques to
measure the g-cell capacitors and extract the acceleration
data from the difference between the two capacitors. The
ASIC also signal conditions and filters (switched capacitor)
the signal, providing a high level output voltage that is
ratiometric and proportional to acceleration.
Figure 3. Simplified Transducer Physical Model versus
Transducer Physical Model
SPECIAL FEATURES
Filtering
The accelerometers contain an onboard 4-pole switched
capacitor filter. A Bessel implementation is used because it
provides a maximally flat delay response (linear phase) thus
preserving pulse shape integrity. Because the filter is realized
using switched capacitor techniques, there is no requirement
for external passive components (resistors and capacitors) to
set the cut-off frequency.
Self-Test
The sensor provides a self-test feature that allows the
verification of the mechanical and electrical integrity of the
accelerometer at any time before or after installation. This
feature is critical in applications such as automotive airbag
systems where system integrity must be ensured over the life
of the vehicle. A fourth
plate
is used in the g-cell as a self-test
plate. When the user applies a logic high input to the self-test
pin, a calibrated potential is applied across the self-test plate
and the moveable plate. The resulting electrostatic force
(Fe =
1
/
2
AV
2
/d
2
) causes the center plate to deflect. The
resultant deflection is measured by the accelerometer's
control ASIC and a proportional output voltage results. This
procedure assures that both the mechanical (g-cell) and
electronic sections of the accelerometer are functioning.
Ratiometricity
Ratiometricity simply means that the output offset voltage
and sensitivity will scale linearly with applied supply voltage.
That is, as you increase supply voltage the sensitivity and
offset increase linearly; as supply voltage decreases, offset
and sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
Status
Freescale accelerometers include fault detection circuitry
and a fault latch. The Status pin is an output from the fault
latch, OR'd with self-test, and is set high whenever one (or
more) of the following events occur:
Supply voltage falls below the Low Voltage Detect (LVD)
voltage threshold
Clock oscillator falls below the clock monitor minimum
frequency
Parity of the EPROM bits becomes odd in number.
The fault latch can be reset by a rising edge on the self-test
input pin, unless one (or more) of the fault conditions
continues to exist.
Acceleration
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MMA3201D | Surface Mount Micromachined Accelerometer(表面安裝微電機(jī)加速計(jì)) |
| MMA3201 | Surface Mount Micromachined Accelerometer |
| MMA3202D | Surface Mount Micromachined Accelerometer |
| MMA3202DR2 | Surface Mount Micromachined Accelerometer |
| MMA3202 | Surface Mount Micromachined Accelerometer |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MMA23-011 | 功能描述:CONN RACK/PANEL 11POS 5A RoHS:否 類別:連接器，互連式 >> 背板 - 專用 系列:MM22 標(biāo)準(zhǔn)包裝:8 系列:PwrBlade® 連接器用途:- 連接器類型:插座，母插口和片狀插口 連接器類型:葉片形電源 位置數(shù):37 加載位置的數(shù)目:全部 間距:0.100"（2.54mm） 行數(shù):4 列數(shù):- 安裝類型:板邊緣，通孔，直角 端子:焊接 觸點(diǎn)布局，典型:24 信號(hào)，13 電源 特點(diǎn):板鎖，導(dǎo)向引腳 觸點(diǎn)表面涂層:金 觸點(diǎn)涂層厚度:30µin（0.76µm） 顏色:黑 包裝:托盤 額定電流:- 材料可燃性額定值:UL94 V-0 工作溫度:-20°C ~ 105°C 額定電壓:- 其它名稱:51793-151793-1-ND |
| MMA23-0111K1 | 功能描述:CONN RACK/PANEL 11POS 5A RoHS:否 類別:連接器，互連式 >> 背板 - 專用 系列:MM22 標(biāo)準(zhǔn)包裝:260 系列:Impact™ 76155 連接器用途:中平面 連接器類型:接頭，公引腳 連接器類型:Impact? 位置數(shù):96 加載位置的數(shù)目:全部 間距:0.053"（1.35mm） 行數(shù):12 列數(shù):8 安裝類型:通孔 端子:壓配式 觸點(diǎn)布局，典型:32 差分對(duì) 特點(diǎn):- 觸點(diǎn)表面涂層:金 觸點(diǎn)涂層厚度:30µin（0.76µm） 顏色:黑 包裝:托盤 額定電流:- 材料可燃性額定值:UL94 V-0 工作溫度:-55°C ~ 85°C 額定電壓:30V 其它名稱:76155-1835761551835 |
| MMA23-0111Q1 | 功能描述:CONN RACK/PANEL 11POS 5A RoHS:否 類別:連接器，互連式 >> 背板 - 專用 系列:MM22 標(biāo)準(zhǔn)包裝:260 系列:Impact™ 76155 連接器用途:中平面 連接器類型:接頭，公引腳 連接器類型:Impact? 位置數(shù):96 加載位置的數(shù)目:全部 間距:0.053"（1.35mm） 行數(shù):12 列數(shù):8 安裝類型:通孔 端子:壓配式 觸點(diǎn)布局，典型:32 差分對(duì) 特點(diǎn):- 觸點(diǎn)表面涂層:金 觸點(diǎn)涂層厚度:30µin（0.76µm） 顏色:黑 包裝:托盤 額定電流:- 材料可燃性額定值:UL94 V-0 工作溫度:-55°C ~ 85°C 額定電壓:30V 其它名稱:76155-1835761551835 |
| MMA23-0111R1 | 功能描述:機(jī)架和面板連接器 Rack & Panel Connector RoHS:否 制造商:AVX 系列: 產(chǎn)品類型: 位置/觸點(diǎn)數(shù)量: 安裝風(fēng)格: 端接類型: 外殼材料: 觸點(diǎn)材料: 觸點(diǎn)電鍍: |
| MMA23-014 | 功能描述:CONN RACK/PANEL 14POS 5A RoHS:否 類別:連接器，互連式 >> 背板 - 專用 系列:MM22 標(biāo)準(zhǔn)包裝:8 系列:PwrBlade® 連接器用途:- 連接器類型:插座，母插口和片狀插口 連接器類型:葉片形電源 位置數(shù):37 加載位置的數(shù)目:全部 間距:0.100"（2.54mm） 行數(shù):4 列數(shù):- 安裝類型:板邊緣，通孔，直角 端子:焊接 觸點(diǎn)布局，典型:24 信號(hào)，13 電源 特點(diǎn):板鎖，導(dǎo)向引腳 觸點(diǎn)表面涂層:金 觸點(diǎn)涂層厚度:30µin（0.76µm） 顏色:黑 包裝:托盤 額定電流:- 材料可燃性額定值:UL94 V-0 工作溫度:-20°C ~ 105°C 額定電壓:- 其它名稱:51793-151793-1-ND |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。