參數(shù)資料
型號: MB89680
廠商: Fujitsu Limited
元件分類: 8位微控制器
英文描述: 8-bit Proprietary Microcontroller
中文描述: 8位微控制器專有
文件頁數(shù): 33/43頁
文件大小: 328K
代理商: MB89680
33
MB89680 Series
7. Notes on Using A/D Converter
Input impedance of the analog input pins
The A/D converter used for the MB89890 series contains a sample hold circuit as illustrated below to fetch
analog input voltage into the sample hold capacitor for eight instruction cycles after starting A/D conversion.
For this reason, if the output impedance of the external circuit for the analog input is high, analog input voltage
might not stabilize within the analog input sampling period. Therefore, it is recommended to keep the output
impedance of the external circuit low (below 10 k
).
Note that if the impedance cannot be kept low, it is recommended to connect an external capacitor of approx.
0.1
μ
F for the analog input pin.
Error
The smaller the | AVR – AV
SS
|, the greater the error would become relatively.
V
OT
V
NT
V
(N + 1)T
V
FST
Digital output
(1 LSB
×
N + V
OT
)
0000
0000
0000
0001
1111
1111
1110
1111
1 LSB =
AVR
256
Linearity error =
Differential linearity error =
Analog input
Actual conversion value
Theoretical conversion value
Total error =
V
NT
– (1 LSB
×
N + V
OT
)
1 LSB
V
( N + 1 ) T
– V
NT
1 LSB
V
NT
– (1 LSB
×
N + 1 LSB)
– 1
1 LSB
Linearity error
Sample hold circuit
C
33 pF
Analog channel selector
Close for 8 instruction cycles after starting
A/D conversion.
If the analog input
impedance is higher
than 10 k
, it is
recommended to
connect an external
capacitor of approx.
0.1
μ
F.
Analog input pin
Comparator
R
6 k
Analog Input Equivalent Circuit
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MB89689 制造商:FUJITSU 制造商全稱:Fujitsu Component Limited. 功能描述:8-bit Proprietary Microcontroller
MB89689PF 制造商:FUJITSU 制造商全稱:Fujitsu Component Limited. 功能描述:8-bit Proprietary Microcontroller
MB896E 制造商:IBase Technology (USA) Inc. 功能描述:ITX, SOCKET 479 FOR PENTIUM/CELERON M, 915GME/ICH6M, W/ ICH - Bulk
MB896EF 制造商:IBase Technology (USA) Inc. 功能描述:ITX, SOCKET 479 FOR PENTIUM/CELERON M, 915GME/ICH6M, W/ 88E8 - Bulk
MB896F-R 制造商:IBase Technology (USA) Inc. 功能描述:ITX, SOCKET 479 FOR PENTIUM/CELERON M, 915GM/ICH6M, W/ 88E80 - Bulk