The LMP91002 device is a programmable Analog Front End (AFE) for use in micro-power
electrochemical-sensing applications. It provides a complete signal path solution between a not
biased gas sensor and a microcontroller generating an output voltage proportional to the cell
current.
The LMP91002’s programmability enables it support not biased electro-chemical gas sensor
with a single design. The LMP91002 supports gas sensitivities over a range of 0.5 nA/ppm to 9500
nA/ppm. It also allows for an easy conversion of current ranges from 5 µA to 750 µA full scale. The
LMP91002’s transimpedance amplifier (TIA) gain is programmable through the
I2C interface. The I2C interface can also be
used for sensor diagnostics. The LMP91002 is optimized for micro-power applications and operates
over a voltage range of 2.7 V to 3.6 V. The total current consumption can be less than 10 µA.
Further power savings are possible by switching off the TIA amplifier and shorting the reference
electrode to the working electrode with an internal switch.
- Typical Values, TA = 25°C
- Supply Voltage 2.7 V to 3.6 V
- Supply Current (Average Over Time) < 10 µA
- Cell Conditioning Current Up to 10 mA
- Reference Electrode Bias Current (85°C) 900-pA
(Maximum) - Output Drive Current 750 µA
- Complete Potentiostat Circuit to Interface to Most
Not Biased Gas Sensors - Low Bias Voltage Drift
- Programmable TIA Gain 2.75 kΩ to 350 kΩ
- I2C-Compatible Digital Interface
- Ambient Operating Temperature –40°C to 85°C
- Package 14-pin WSON
- Supported by Webench Sensor AFE Designer