Sensor AFE System

Complete, integrated signal path solution between sensor and microcontroller

National Semiconductor's Sensor AFE products are configurable ICs designed to interface with specific types of sensors. The Sensor AFE is part of an integrated hardware and software system that allows customers to quickly create a design solution, configure the solution to their specific requirements, and move rapidly to prototyping.

Sensor AFE

  • Design and configure solutions online or on the bench
  • Prototype quickly on bench
  • Easily calibrate and run diagnostic tests
  • Simplify manufacturing
  • Reduce time-to-market


LMP90xxx Family – Multi-Channel 16- & 24-bit Sensor AFE

The LMP90xxx Sensor AFE family features the industry's only low-power, fully configurable 16- and 24-bit ΣΔ ADCs with true continuous background calibration, eliminating gain and offset drift over time and temperature and making them ideal for critical performance and low power applications.


  • Multi-channel Sensor AFE with a 16- or 24-bit Sigma Delta ADC core
  • Flexible, programmable mux (4 differential, 7 single-ended, or a combination inputs)
  • Continuous background sensor diagnostics reduces downtime and improves system efficiency
  • Quick design and evaluation
  • Ideal for high-precision, multi-sensor temperature, pressure, load, and force applications
  • Industrial, process control, medical, and test & measurement applications

LMP90xxx Sensor AFE Portfolio

Resolution Current Sources Inputs
4 Diff / 7 SE 2 Diff / 4 SE
24-bit Yes LMP90100 *LMP90098
24-bit No *LMP90099 *LMP90097
16-bit Yes *LMP90080 *LMP90078
16-bit No *LMP90079 *LMP90077
* New Product

LMP91000 – Micro-Power Chemical Sensor AFE

Programmable cell bias and output amplification enables the LMP91000 to replace multiple discrete solutions for chemical sensing applications. The integrated module design supports multiple sensors with a single solution without board modification. It enables smaller total solutions that consume very little power and reduces assembly and logistics costs. The I2C interface facilitates sensor testing, maximizes performance, and maintains reliability. WEBENCH Sensor AFE Designer reduces design time and provides performance and configuration for all signal path solutions. A prototype system can be delivered in days.


  • Single configurable solutions for potentiostat applications
  • Programmable cell bias
  • Programmable TIA gain
  • Integrated temperature sensor for external temp monitoring/correction
  • –40 to 85°C temperature range


  • ±0.5% to ±3% performance range
  • < 10 μA supply current
  • Eight configurable TIA gains
  • 900 pA max ref. electrode bias current
  • up to 10 mA cell conditioning currents
  • > 650 μA output drive current
  • 2.7 to 5.25V supply voltage

Gas Sensors / Applications

  • Carbon Monoxide
  • Methane
  • Hydrogen Sulphide
  • Sulphur Dioxide
  • Ammonia
  • Ozone
  • Ethylene Oxide
  • Oxygen*
  • Hydrogen Chloride
  • Hydrogen
  • Hydrogen Cyanide
  • Nitric Oxide
  • Nitrogen Dioxide
  • Chlorine
  • Phosphines

* LMP91000 supports oxygen sensing applications as part of a multi-sensor system. Single sensor oxygen application may use an alternate approach.

Integrated Software Tool

Select Sensor > Configure Signal Path > Optimize Design > Load to Sensor AFE

Sensor AFE software shows all configurable elements for easy online or on-bench design. Simply select a sensor, configure the signal path, optimize your design, and load to a Sensor AFE for immediate prototyping.

Step 1: Select sensor type, model, or enter required parameters.
Step 2: Configure range, offset, gain, sample rate, and diagnostics for each signal path.
Step 3: Review performance, store configuration data, and load to Sensor AFE.
Sensor AFE System Diagram

Sensor AFE - PTM

Sensor AFE Overview