LMP91002_16 Datasheet, PDF (1/31 Pages) Texas Instruments – Sensor AFE System

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LMP91002
SNIS163B – APRIL 2012 – REVISED OCTOBER 2015
LMP91002 Sensor AFE System: Configurable AFE Potentiostat for Low-Power Chemical
Sensing Applications
1 Features
•1 Typical Values, T_A = 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
2 Applications
• Gas Detectors
• Amperometric Applications
• Electrochemical Blood Glucose Meters
3 Description
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.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LMP91002
WSON (14)
4.00 mm × 4.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
3-Lead
Electrochemical
Cell
CE
LMP91002
VREF
VDD
+
A1
-
DIAGNOSTIC
VREF
DIVIDER
I2C INTERFACE
AND
CONTROL
REGISTERS
SCL
SDA
MENB
MSP430
CE
RE
RE
WE
DGND
WE
RLoad
+
TIA
-
VOUT
RTIA
C1
C2
AGND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.