收藏本站
Thermal/Linear Intelligent Sensor PICtail? Plus Daughter Board
The single-ended output of the TC1047A device is routed to an MCP617 dual op amp
device. The two op amps in this device are configured to serve as an anti-aliasing
low-pass filter, identical to the filter used in the thermocouple signal conditioning circuit.
The output of this filter is routed to pin 70 of the PICtail Plus interface header J4 on the
Explorer 16 Development Board, for analog-to-digital conversion and further
processing by a dsPIC33F or PIC24H device. For a dsPIC33FJ12GP202 PIM, this pin
is routed to the ADC input AN8 of the dsPIC33FJ12GP202 device.
2.2.3
Linear Sensor Signal Conditioning
The Daughter Board also contains a generic signal interface for any linear sensor
signals with a maximum peak-to-peak voltage of 3.3V. The signal can come from a
sensor located external to the board; alternately, it can simply be an artificially
generated signal (e.g., from a function generator) used to model a particular sensor
output during application development. Whatever the source, the signal can be
supplied to pins 1 and 2 on connector J3, or only supplied to pin 1 with pin 2 grounded.
Often, the signal may be bipolar, which means it can have values less than 0V. Since
the signal is required to be sampled by the on-chip ADC on a dsPIC33F or PIC24H
device, its level must be shifted up such that the signal becomes unipolar, so that it
stays above 0V at all times. This functionality, illustrated in Figure 2-3, is provided by a
level shifter circuit on the Daughter Board. The level shifter is implemented using one
op amp of an MCP602 dual op amp device. This level shifter circuit is essentially an
inverting differential amplifier, with the non-inverting input derived from the positive
voltage rail. The level of the signal midpoint can be adjusted (between 0V and 3.3V)
using potentiometer R30, and the level shifter circuit can be included or bypassed by
installing a jumper in the 1-2 position (indicated on the Daughter Board by an arrow
beside the jumper) or the 2-3 position, respectively, of jumper JP2.
The other op amp in the MCP602 acts as a buffer. A buffer is essentially a non-inverting
amplifier with unity gain, and prevents the output circuit from loading the input circuit
and distorting the signals as a result.
The output of the buffer is provided to an anti-aliasing low-pass filter, implemented as
an 8th-order Sallen-Key structure. The output of this filter is routed to pin 38 of the
PICtail Plus interface header J4 on the Explorer 16 Development Board, for
analog-to-digital conversion and further processing by a dsPIC33F or PIC24H device.
For a dsPIC33FJ12GP202 PIM, this pin is routed to the ADC input AN7 of the
dsPIC33FJ12GP202 device.
FIGURE 2-3:
+1.65V
LEVEL SHIFTER OPERATION
+3.3V
+1.65V
0V
-1.65V
Before Level Shifter
DS70574A-page 16
0V
After Level Shifter
? 2008 Microchip Technology Inc.
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
AC323027 BOARD EVAL PIC32 CAP TOUCH CTMU
ACCRFBOUTON29JF BLACK COMMAND KNOB
ACJ2212 RELAY AUTOMOTIVE SPDT 20A 12V
ACNH3212 RELAY AUTOMOTIVE SPST 30A 12V
ACNM5112SAX RELAY AUTO SPDT 30A 12V
ACT212 RELAY AUTOMOTIVE SPDT 20A 12V
ACV33224 RELAY AUTOMOTIVE SPST 20A 24V
ACW212 RELAY AUTOMOTIVE DPST 45A 12V
相关代理商/技术参数
AC164136 功能描述:开发板和工具包 - PIC / DSPIC ZeroG 802.11 Dev Kt for Explorer 16 RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压:
AC164136-2 功能描述:开发板和工具包 - 无线 ZeroG Wi-Fi PICtail Daughter Board RoHS:否 制造商:Arduino 产品:Evaluation Boards 工具用于评估:AT32UC3L 核心:AVR32 频率: 接口类型:USB 工作电源电压:5 V
AC164136-4 功能描述:射频开发工具 MRF24WB0MA Wi-Fi PICtail+ Daughter Bd 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
AC164137-1 功能描述:子卡和OEM板 434MHz Daughter Board RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
AC164137-1 制造商:Microchip Technology Inc 功能描述:MRF49XA PICtail/PICtail Plus Daughter Bo
AC164137-2 功能描述:子卡和OEM板 868/915MHz Daughter Board RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
AC164137-2 制造商:Microchip Technology Inc 功能描述:MRF49XA PICtail/PICtail Plus Daughter Bo
AC164138-1 功能描述:子卡和OEM板 MRF89XAM8A PICtail PICtail + Daught Brd RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit