Global Sources
EE Times-India
Stay in touch with EE Times India
EE Times-India > Sensors/MEMS

Single-chip gas, pH sensor AFEs simplify design

Posted: 13 Mar 2012     Print Version  Bookmark and Share

Keywords:gas sensor  AFE  pH sensor 

Texas Instruments Inc. (TI) debuts two configurable analogue front ends (AFE) that offer a single-chip solution across multiple non dispersive infrared (NDIR) gas sensor and pH sensor platforms instead of designing several complex discrete solutions.

 Gas sensing and pH sensing AFEs

TI's gas sensing and pH sensing AFEs are offered as a single-chip solution.

Offering an easy-to-use, modular solution for bridging the gap between the microprocessor and sensor, the AFEs team with TI's WEBENCH Sensor AFE Designer software and bench-top development system. These tools allow engineers to select a sensor, design and configure the solution and download configuration data to the sensor AFE for immediate prototyping, according to the company

The highly-integrated LMP91050 NDIR gas sensing AFE supports multiple thermopile sensors for NDIR sensing, indoor CO2 monitoring, demand control ventilation, HVAC, alcohol breath analysis, greenhouse gas monitoring and Freon detection.

LMP91050 NDIR Gas Sensing AFE features and benefits:
 • Complete gas sensing solution
: AFE integrates a programmable gain amplifier (PGA), "dark phase" offset cancellation circuitry, adjustable common-mode generator, and SPI interface to simplify system design.
 • Programmable gain amplifier: Features low gain range and high gain range, allowing the use of thermopiles with different sensitivities.
 • Well-specified performance: Low gain drift of 100ppm/°C (maximum), output offset drift of 1.2mV/°C, phase delay variation of 500ns, low noise at 0.1µV rms (0.1 to 10Hz), and operation between -40°C to 105°C provide optimised system performance.
 • Small form factor: Integration shrinks package to 3mm x 4.9mm, enabling smaller end products.

The highly-integrated LMP91200 pH sensing AFE supports two electrode pH sensors used in analyser platforms for emissions monitoring, steam and water quality monitoring, chemical/petrochemical plants, food processing and more.

LMP91200 pH Sensing AFE features and benefits:
 • Complete pH sensing solution
: AFE integrates a PGA, ultra-low input-bias pH buffer, signal guarding, temperature and measurement calibration, and common-mode generation and diagnostics circuitry, allowing use of a single chip to interface to most of today's pH sensors.
 • Higher reliability and system accuracy: On-board sensor test ensures proper connection and functionality, and ultra-low bias current of 0.4pA (maximum) boosts system reliability and accuracy while also protecting the pH electrodes during no supply situations.
 • Wide operating range: Operation from 1.8V to 5.5V and -40°C to 125°C, with a guaranteed low pH buffer input bias current across the operating range, provides maximum flexibility.
 • Small form factor: Integration shrinks package to 5mm x 6.4mm, enabling smaller end products.

TI offers the entire signal chain for sensing applications, enabling engineers to combine components from the following families: Sensor AFE, MSP430 ultra low power 16bit microcontroller, and 4 to 20mA transmitters such as the DAC161P997 and XTR117.

Available today in volume, the LMP91050 gas sensing AFE is offered in a 10-pin MSOP package, and the LMP91200 pH sensing AFE is supplied in a 16-pin TSSOP package. The suggested retail price for the LMP91050 is Rs.65.35 ($1.32) and the LMP91200 is Rs.193.07 ($3.90), both in 1,000-unit quantities.

Comment on "Single-chip gas, pH sensor AFEs simp..."
*  You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.


Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

Back to Top