166
9152BINDCO02/10
ATA8743
25.10 Register Description
25.10.1 ADMUX ADC Multiplexer Selection Register
" Bit 7:6 REFS1:REFS0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in Table 25-3 on page 166. If
these bits are changed during a conversion, the change will not go in effect until this conversion
is complete (ADIF in ADCSR is set).
Special care should be taken when changing differential channels. Once a differential channel
has been selected, the stage may take as much as 25 ADC clock cycles to stabilize to the new
value. Thus conversions should not be started within the first 13 clock cycles after selecting a
new differential channel. Alternatively, conversion results obtained within this period should be
discarded.
The same settling time should be observed for the first differential conversion after changing
ADC reference (by changing the REFS1:0 bits in ADMUX).
If channels where differential gain is used ie. the gainstage, using V
CC
or an optional external
AREF higher than (V
CC
- 1V) is not recommended, as this will affect ADC accuracy. It is not
allowed to connect internal voltage reference to AREF pin, if an external voltage is being applied
to it already. Internal voltage reference is connected AREF pin when REFS1:0 is set to value
11.
" Bits 5:0 MUX5:0: Analog Channel and Gain Selection Bits
The value of these bits selects which combination of analog inputs are connected to the ADC. In
case of differential input, gain selection is also made with these bits. Selections on Table 25-4 on
page 167 show values for single-ended channels and where the differential channels as well as
the offset calibration selections are located. Selecting the single-ended channel ADC8 enables
the temperature measurement. See Table 25-4 on page 167 for details. If these bits are
changed during a conversion, the change will not go into effect until this conversion is complete
(ADIF in ADCSRA is set).
Bit
7
6
5
4
3
2
1
0
0x07 (0x27)
REFS1
REFS0
MUX5
MUX4
MUX3
MUX2
MUX1
MUX0
ADMUX
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Table 25-3. Voltage Reference Selections for ADC
REFS1
REFS0
Voltage Reference Selection
0
0
V
CC
used as analog reference, disconnected from PA0 (AREF).
0
1
External Voltage Reference at PA0 (AREF) pin, Internal Voltage Reference
turned off.
1
0
Internal 1.1V Voltage Reference.
1
1
Reserved.
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
ATAVRRZ200
KIT DEMO AT86RF230
AV101-12LF
ATTENUATOR HIP3 0.70-1GHZ 8-SOIC
AV102-12LF
ATTENUATOR HIP3 1.7-2GHZ 8SOIC
AV113-12LF
ATTENUATOR HIP3 2.1-2.3GHZ 8SOIC
AXUV100G
SENSOR ELECTRON DETECTION
B0205F50200AHF
XFRMR BALUN RF 200-500MHZ 1608
B0310J50100AHF
XFRMR BALUN RF 300-1000MHZ 0805
B0322J5050AHF
XFRMR BALUN RF 300-2200MHZ 0805
相关代理商/技术参数
ATAB5275
功能描述:射频开发工具 LF Tx Antenna driver board (TPMS) RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5276
功能描述:射频开发工具 1A Antenna Driver Demoboard RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5278
功能描述:射频开发工具 LF Tx Antenna driver board (PEG) RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5279
功能描述:射频开发工具 LF Transmitter with ATA5279 RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5282
功能描述:BOARD EVAL LF 125KHZ ANT DVR 3CH RoHS:是 类别:RF/IF 和 RFID >> RFID 评估和开发套件及电路板 系列:Smart RF 产品培训模块:M24LR64 Dual Interface EEPROM 标准包装:1 系列:- 类型:读取器模块 频率:13.56MHz 适用于相关产品:M24LR-64-R 已供物品:2 根基准天线，I2C 和 RFID 读取器，样品 其它名称:497-10480
ATAB5283
功能描述:射频开发工具 LF Rx Board 1 channel (TPMS)
RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5423-3-B
功能描述:射频开发工具 UHF Transceiver Base station Board 315MHz
RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V
ATAB5423-3-WB
功能描述:射频开发工具 UHF TRx Application Board 315MHz RoHS:否 制造商:Taiyo Yuden 产品:Wireless Modules 类型:Wireless Audio 工具用于评估:WYSAAVDX7 频率: 工作电源电压:3.4 V to 5.5 V