參數(shù)資料
型號(hào)： PIC12C67X
廠商： Microchip Technology Inc.
英文描述： 8-Pin, 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory
中文描述： 8引腳，8位CMOS微控制器與A / D轉(zhuǎn)換器和EEPROM數(shù)據(jù)存儲(chǔ)器
文件頁(yè)數(shù)： 48/129頁(yè)
文件大小： 931K
代理商： PIC12C67X
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)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)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)當(dāng)前第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)
PIC12C67X
DS30561B-page 48
1999 Microchip Technology Inc.
8.1
For the A/D converter to meet its specified accuracy,
the charge holding capacitor (C
HOLD
) must be allowed
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 8-2. The source
impedance (R
S
) and the internal sampling switch (R
SS
)
impedance directly affect the time required to charge
the capacitor C
HOLD
. The sampling switch (R
SS
)
impedance varies over the device voltage (V
DD
), see
Figure 8-2.
The maximum recommended imped-
ance for analog sources is 10 k
. After the analog
input channel is selected (changed), this acquisition
must be done before the conversion can be started.
To calculate the minimum acquisition time, Equation 8-1
may be used. This equation assumes that 1/2 LSb error
is used (512 steps for the A/D). The 1/2 LSb error is the
maximum error allowed for the A/D to meet its specified
resolution.
A/D Sampling Requirements
EQUATION 8-1:
A/D MINIMUM CHARGING
TIME
V
HOLD
= (V
REF
- (V
REF
/512)) (1 - e
(-Tc/C
HOLD
(R
IC
+ R
SS
+ R
S
))
)
or
Tc = -(51.2 pF)(1 k
+ R
SS
+ R
S
) ln(1/511)
Example 8-1 shows the calculation of the minimum
required acquisition time T
ACQ
. This calculation is
based on the following system assumptions.
Rs = 10 k
1/2 LSb error
V
DD
= 5V
→
Rss = 7 k
Temp (system max.) = 50
°
C
V
HOLD
= 0 @ t = 0
EXAMPLE 8-1:
CALCULATING THE
MINIMUM REQUIRED
SAMPLE TIME
T
ACQ
= Internal Amplifier Settling Time +
Holding Capacitor Charging Time +
Temperature Coefficient
T
ACQ
= 5
μ
s + Tc + [(Temp - 25
°
C)(0.05
μ
s/
°
C)]
T
C
=
-C
HOLD
(R
IC
+ R
SS
+ R
S
) ln(1/512)
-51.2 pF (1 k
+ 7 k
+ 10 k
) ln(0.0020)
-51.2 pF (18 k
) ln(0.0020)
-0.921
μ
s (-6.2146)
5.724
μ
s
T
ACQ
= 5
μ
s + 5.724
μ
s + [(50
°
C - 25
°
C)(0.05
μ
s/
°
C)]
10.724
μ
s + 1.25
μ
s
11.974
μ
s
Note 1:
The reference voltage (V
REF
) has no
effect on the equation, since it cancels
itself out.
2:
The charge holding capacitor (C
HOLD
) is
not discharged after each conversion.
3:
The maximum recommended impedance
for analog sources is 10 k
. This is
required to meet the pin leakage specifi-
cation.
4:
After a conversion has completed, a
2.0 T
AD
delay must complete before
acquisition can begin again. During this
time, the holding capacitor is not con-
nected to the selected A/D input channel.
FIGURE 8-2:
ANALOG INPUT MODEL
C
PIN
5 pF
VA
Rs
RAx
V
DD
V
T
= 0.6V
V
T
= 0.6V
I leakage
± 500 nA
R
IC
≤
1k
Sampling
Switch
SS
Rss
C
HOLD
= DAC capacitance
= 51.2 pF
V
SS
6V
5V
4V
3V
2V
Sampling Switch
( k
)
5 6 7 8 9 10 11
V
DD
Legend: C
PIN
V
T
I leakage
R
IC
SS
C
HOLD
= input capacitance
= threshold voltage
= leakage current at the pin due to
various junctions
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
相關(guān)PDF資料
PDF描述
pic12ce674 8-Pin, 8-Bit CMOS Microcontroller with A/D Converter(具A/D轉(zhuǎn)換器和EEPROM數(shù)據(jù)存儲(chǔ)器的8位微控制器)
PIC12CR509A 8-Pin, 8-Bit CMOS Microcontrollers
PIC12F505 8/14-Pin, 8-Bit Flash Microcontrollers
PIC12F506 8/14-Pin, 8-Bit Flash Microcontroller
PIC12F510_07 8/14-Pin, 8-Bit Flash Microcontroller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC12C67X_13 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory
PIC12CE-04/EJW 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12CE-04/EP 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12CE-04/ESM 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
PIC12CE-04/ESN 制造商:MICROCHIP 制造商全稱(chēng):Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontrollers
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*