- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383589 > MCP3221 (Microchip Technology Inc.) 560KBITS BRAM 400000 SYSTEM GATES 404 I/ - NOT RECOMMENDED for NEW DESIGN PDF資料下載
參數(shù)資料
| 型號(hào)： | MCP3221 |
| 廠商： | Microchip Technology Inc. |
| 英文描述： | 560KBITS BRAM 400000 SYSTEM GATES 404 I/ - NOT RECOMMENDED for NEW DESIGN |
| 中文描述： | 低功耗12位A / D轉(zhuǎn)換器具有I2C⑩接口 |
| 文件頁(yè)數(shù)： | 19/27頁(yè) |
| 文件大?。?/td> | 520K |
| 代理商： | MCP3221 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)當(dāng)前第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)
2003 Microchip Technology Inc.
DS21732B-page 19
MCP3221
6.3
Device Polling
In some instances, it may be necessary to test for
MCP3221 presence on the I
2
C bus without performing
a conversion. This operation is described in Figure 6-4.
Here we are setting the R/W bit in the address byte to
a zero. The MCP3221 will then acknowledge by pulling
SDA low during the ACK clock and then release the
bus back to the I
2
C master. A stop or repeated start bit
can then be issued from the master and I
2
C
communication can continue.
FIGURE 6-4:
Device Polling.
6.4
Device Power and Layout
Considerations
6.4.1
POWERING THE
MCP3221
V
DD
supplies the power to the device as well as the ref-
erence voltage. A bypass capacitor value of 0.1 μF is
recommended. Adding a 10 μF capacitor in parallel is
recommended to attenuate higher frequency noise
present in some systems.
FIGURE 6-5:
Powering the
MCP3221
.
6.4.2
LAYOUT CONSIDERATIONS
When laying out a printed circuit board for use with
analog components, care should be taken to reduce
noise wherever possible. A bypass capacitor from
V
DD
to ground should always be used with this device and
should be placed as close as possible to the device pin.
A bypass capacitor value of 0.1 μF is recommended.
Digital and analog traces should be separated as much
as possible on the board, with no traces running under-
neath the device or the bypass capacitor. Extra precau-
tions should be taken to keep traces with high-
frequency signals (such as clock lines) as far as
possible from analog traces.
Use of an analog ground plane is recommended in
order to keep the ground potential the same for all
devices on the board. Providing V
DD
connections to
devices in a “star” configuration can also reduce noise
by eliminating current return paths and associated
errors (Figure 6-6). For more information on layout tips
when using the MCP3221 or other ADC devices, refer
to AN688,
“Layout Tips for 12-Bit A/D Converter
Applications”
.
FIGURE 6-6:
‘Star’ configuration in order to reduce errors
caused by current return paths.
V
DD
traces arranged in a
6.4.3
USING A REFERENCE FOR
SUPPLY
The MCP3221 uses V
DD
as both power and a refer-
ence. In some applications, it may be necessary to use
a stable reference to achieve the required accuracy.
Figure 6-7 shows an example using the MCP1541 as a
4.096V, 2% reference.
FIGURE 6-7:
Reference Configuration.
Stable Power and
1 2 3 4 5 6 7 8 9
SCL
SDA
1 0 0
1
A2A1A0 0
A
Start
Bit
Address Byte
Address bits
Device bits
R/W
Start
Bit
MCP3221
response
V
DD
V
DD
A
IN
SCL
SDA
To
Microcontroller
10 μF
MCP3221
0.1 μF
V
DD
R
PU
R
PU
V
DD
Connection
Device 1
Device 2
Device 3
Device 4
V
DD
V
DD
SCL
4.096V
Reference
1 μF
0
MCP1541
C
L
A
IN
T
M
MCP3221
V
DD
R
PU
SDA
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MCP3221T | 560KBITS BRAM 400000 SYSTEM GATES 404 - - NOT RECOMMENDED for NEW DESIGN |
| MCP3553 | Low-Power, Single-Channel 22-Bit Delta-Sigma ADCs |
| MCP3553E | Low-Power, Single-Channel 22-Bit Delta-Sigma ADCs |
| MCP3551 | Low-Power, Single-Channel 22-Bit Delta-Sigma ADCs |
| MCP3551E | SENSOR COMP LOAD CELL 2LBF |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MCP3221_06 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Low Power 12-Bit A/D Converter With I2C⑩ Interface |
| MCP3221A0-E/OT | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Low Power 12-Bit A/D Converter With I2C⑩ Interface |
| MCP3221A0-I/OT | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Low Power 12-Bit A/D Converter With I2C⑩ Interface |
| MCP3221A0T-E/OT | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit ADC I2C Single Channel RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32 |
| MCP3221A0T-I/OT | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Low Power 12-Bit A/D Converter With I2C⑩ Interface |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。