TI 公司的LMP91050是可編程的傳感器模擬前端（AFE），最適合用于溫度傳感器和非分散紅外（NDIR）檢測(cè)應(yīng)用。器件提供了傳感器和MCU間完整的通路，可編程增益從167V/V到7986V/V，工作電壓2.7V 到5.5V，(0.1 到10 Hz)噪音為 0.1μVRMS，最大增益漂移為100 ppm/℃，相位漂移為500ns，主要用在NDIR檢測(cè)，通風(fēng)控制，建筑物監(jiān)測(cè)，汽車(chē)電子的CO2艙控制和酒精檢測(cè)，GHG和氟利昂檢測(cè)平臺(tái)。本文介紹了LMP91050主要指標(biāo)和特性，方框圖，典型NDIR傳感應(yīng)用電路圖以及SPIO-4精密信號(hào)通路控制器板主要特性，方框圖，電路圖和PCB元件布局圖。
Configurable AFE for Nondispersive Infrared (NDIR) Sensing Applications
The LMP91050 is a programmable integrated Sensor Analog Front End (AFE) optimized for thermopile sensors, as typically used in NDIR applications. It provides a complete signal path solution between a sensor and microcontroller that generates an output voltage proportional to the thermopile voltage. The LMP91050 s programmability enables it to support multiple thermopile sensors with a single design as opposed to the multiple discrete solutions.
The LMP91050 features a programmable gain amplifier (PGA), "dark phase" offset cancellation, and an adjustable common mode generator (1.15V or 2.59V) which increases output dynamic range. The PGA offers a low gain range of 167V/V to 1335V/V plus a high gain range of 1002V/V to 7986V/V which enables the user to utilize thermopiles with different sensitivities.
LMP91050主要指標(biāo)：
■ Programmable gain 167V/V to 7986V/V
■ Low noise (0.1 to 10 Hz) 0.1μVRMS
■ Gain Drift 100 ppm/°C (max)
■ Phase Delay Drift 500ns (max)
■ Power supply voltage range 2.7V to 5.5V
LMP91050主要特性：
Programmable gain amplifier
"Dark Signal" offset cancellation
Supports external filtering
Common mode generator and 8 bit DAC
10 pin MSOP package
LMP91050應(yīng)用：
NDIR sensing
Demand control ventilation
Building monitoring
CO2 cabin control — Automotive
Alcohol detection — Automotive
Industrial safety and security
GHG & Freons detection platforms
圖1。LMP91050方框圖
圖2。LMP91050典型NDIR傳感應(yīng)用電路圖
SPIO-4精密信號(hào)通路控制器板
The SPIO-4 is one of several National Semiconductor digital controller/capture boards that are used by multiple evaluation systems. The objective of these software/hardware evaluation systems is to allow our customers to easily and accurately evaluate National s signal-path devices in a lab setting. At the time of SPIO-4 s release, two different evaluation system software (GUIs) make use of this board: the WaveVision-5 and the Sensor AFE. The board ships with the current version of the WaveVision-5 software.
In addition to the controller/capture board (i.e., the SPIO-4) and the evaluation GUI software (e.g.,WaveVision-5 or Sensor AFE), the third essential element of an evaluation system is the device or signalpath evaluation board that plugs into the controller board. This eval board is generically referred to as the “DUT board”. Each DUT board comes with its own Users Guide which documents its specific features.
Each DUT board also comes with some software that the user must install before using it. In the case of the WaveVision-5 GUI, this software is essentially a device-specific module that adds support for the future device eval boards. In the case of Sensor AFE device family, the eval board comes with a complete, custom Sensor AFE that is specifically paired with that device.
The WaveVision-5 and Sensor AFE GUI software have their own Users
Guide documents that describe how to interact with the GUI.
This User
s Guide describes only the SPIO-4 board. The user is expected to refer to this guide only if necessary. The DUT Users
Guide and the GUI Users
Guide are the primary documents that describehow to work with a National signal-path evaluation board.
SPIO-4系統(tǒng)特性：
Captures or sources multiple signal-path data streams and transfers them to/from the PC based application software through a USB 2.0 connection (USB1.1 compatible).
Supports jumper-less, plug-and-play configuration. The GUI automatically discovers the attached DUT board and loads the appropriate software module for it.
Supports a wide variety of signal-path evaluation board through a standardized connector (GPSI-16/GPSI-32).
Capable of storing up to 8MBytes of signal-path data.
DUT interface can be SPI, I2C or parallel.
Powered either by PC via USB or external supply
Atmel SAM3U microcontroller (ARM Cortex M3 Core)
Available IDE connector for Atmel firmware development environment
USB 2.0 port
USB-powered
Maximum serial clock rate of 80 MHz
Xilinx XC6SLX16 FPGA
Standard `GPSI-16` connector that allows connection to many National precision signal-path devices
圖3。SPIO-4精密信號(hào)通路控制器板外形圖
圖4。SPIO-4精密信號(hào)通路控制器板方框圖
圖5。SPIO-4精密信號(hào)通路控制器板電路圖（1）
圖6。SPIO-4精密信號(hào)通路控制器板電路圖（2）
圖7。SPIO-4精密信號(hào)通路控制器板電路圖（3）
圖8。SPIO-4精密信號(hào)通路控制器板電路圖（4）
圖9。SPIO-4精密信號(hào)通路控制器板電路圖（5）
圖10。SPIO-4精密信號(hào)通路控制器板電路圖（6）
圖11。SPIO-4精密信號(hào)通路控制器板電路圖（7）
圖12。SPIO-4精密信號(hào)通路控制器板電路圖（8）
圖13。SPIO-4精密信號(hào)通路控制器板電路圖（9）
圖14。SPIO-4精密信號(hào)通路控制器板電路圖（10）
圖15。SPIO-4精密信號(hào)通路控制器板元件布局圖
詳情請(qǐng)見(jiàn)：
http://www.ti.com/lit/ds/snas517b/snas517b.pdf
和
http://www.ti.com/lit/ug/snau112/snau112.pdf
