and it is not referenced to ana" />
參數(shù)資料
型號(hào): 20-101-1105
廠商: Rabbit Semiconductor
文件頁數(shù): 51/112頁
文件大?。?/td> 0K
描述: MODULE RCM4100 RABBITCORE
標(biāo)準(zhǔn)包裝: 1
系列: RabbitCore®
模塊/板類型: MPU 核心模塊
適用于相關(guān)產(chǎn)品: RCM4100
其它名稱: 316-1121
User’s Manual
39
If a device such as a battery is
connected across two channels
for a differential measurement,
and it is not referenced to
analog ground, then the current
from the device will flow
through both sets of attenuator
resistors without flowing back
to analog ground as shown in
Figure 10. This will generate a
negative voltage at one of the
inputs, LN1, which will almost
certainly lead to inaccurate A/D
conversions. To make such differential measurements, connect the R1 resistors to the A/D
converter’s internal reference voltage, which is software-configurable for 1.15 V, 2.048 V,
or 2.5 V. This internal reference voltage is available on pin 49 of header J3 as VREF, and
allows you to convert analog input voltages that are negative with respect to analog ground.
NOTE: The amplifier inside the A/D converter’s internal voltage reference circuit has a
very limited output-current capability. The internal buffer can source up to 20 mA and
sink only up to 200 A. Use a separate buffer amplifier if you need to supply any load
current.
The A/D converter’s CONVERT pin is available on pin 48 of header J3 and can be used as
a hardware means of forcing the A/D converter to start a conversion cycle at a specific time.
The CONVERT signal is an edge-triggered event and has a hold time of two CCLK periods
for debounce.
A conversion is started by an active (rising) edge on the CONVERT pin. The CONVERT
pin must stay low for at least two CCLK periods before going high for at least two CCLK
periods. Figure 11 shows the timing of a conversion start. The double falling arrow on
CCLK indicates the actual start of the conversion cycle.
Figure 11. Timing Diagram for Conversion Start Using CONVERT Pin
Appendix B.4.3 explains the implementation examples of these features on the Prototyp-
ing Board.
Figure 10. Current Flow from Ungrounded
or Floating Source
R5
R6
2.2 nF
R14
R13
2.2 nF
ADC
AIN0
AIN1
+
I
LN0
LN1
+
-
Device
CCLK
BUSY
CONV
Conversion starts
相關(guān)PDF資料
PDF描述
20-101-1028 MODULE RABBITCORE RCM3750
046232104015800+ CONN FFC/FPC 4POS 1MM VERT SMD
20-101-0454 MODULE RABBITCORE RCM2200
20-101-0405 MODULE RABBITCORE RCM2010
20-101-1093 RCM4110 RABBITCORE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
20-101-1110 功能描述:界面開發(fā)工具 Rio Protyping Board RoHS:否 制造商:Bourns 產(chǎn)品:Evaluation Boards 類型:RS-485 工具用于評(píng)估:ADM3485E 接口類型:RS-485 工作電源電壓:3.3 V
20-101-1112 功能描述:模塊化系統(tǒng) - SOM RCM4010 Core Module RoHS:否 制造商:Digi International 外觀尺寸:ConnectCore 9P 處理器類型:ARM926EJ-S 頻率:150 MHz 存儲(chǔ)容量:8 MB, 16 MB 存儲(chǔ)類型:NOR Flash, SDRAM 接口類型:I2C, SPI, UART 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 尺寸:1.97 in x 1.97 in x 6.1 in
20-101-1114 功能描述:開發(fā)板和工具包 - 其他處理器 RCM4010 Kit RoHS:否 制造商:Freescale Semiconductor 產(chǎn)品:Development Systems 工具用于評(píng)估:P3041 核心:e500mc 接口類型:I2C, SPI, USB 工作電源電壓:
20-101-1131 功能描述:模塊化系統(tǒng) - SOM RCM4200 RabbitCore- Module RoHS:否 制造商:Digi International 外觀尺寸:ConnectCore 9P 處理器類型:ARM926EJ-S 頻率:150 MHz 存儲(chǔ)容量:8 MB, 16 MB 存儲(chǔ)類型:NOR Flash, SDRAM 接口類型:I2C, SPI, UART 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 尺寸:1.97 in x 1.97 in x 6.1 in
20-101-1132 功能描述:模塊化系統(tǒng) - SOM RCM4210 RabbitCore- Module RoHS:否 制造商:Digi International 外觀尺寸:ConnectCore 9P 處理器類型:ARM926EJ-S 頻率:150 MHz 存儲(chǔ)容量:8 MB, 16 MB 存儲(chǔ)類型:NOR Flash, SDRAM 接口類型:I2C, SPI, UART 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 尺寸:1.97 in x 1.97 in x 6.1 in