Datasheet

LMP90100

SNAS510P –JANUARY 2011–REVISED MARCH 2013

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• True Continuous Background Calibration

The LMP90100/LMP90099/LMP90098/LMP90097 feature a 24 bit ΣΔ core with continuous background

calibration to compensate for gain and offset errors in the ADC, virtually eliminating any drift with time and

temperature. The calibration is performed in the background without user or ADC input interruption, making it

unique in the industry and eliminating down time associated with field calibration required with other solutions.

Having this continuous calibration improves performance over the entire life span of the end product.

• Continuous Background Sensor Diagnostics

Sensor diagnostics are also performed in the background, without interfering with signal path performance,

allowing the detection of sensor shorts, opens, and out-of-range signals, which vastly improves system reliability.

In addition, the fully flexible input multiplexer described below allows any input pin to be connected to any ADC

input channel providing additional sensor path diagnostic capability.

• Flexible Input MUX Channels

The flexible input MUX allows interfacing to a wide range of sensors such as thermocouples, RTDs, thermistors,

and bridge sensors. The LMP90100/LMP90099’s multiplexer supports 4 differential channels while the

LMP90098/LMP90097 supports 2. Each effective input voltage that is digitized is VIN = VINx – VINy, where x

and y are any input. In addition, the input multiplexer of the LMP90100/LMP90099 also supports 7 single-ended

channels (LMP90098/LMP90097 supports 4), where the common ground is any one of the inputs.

• Programmable Gain Amplifiers (FGA & PGA)

The LMP90100/LMP90099/LMP90098/LMP90097 contain an internal 16x fixed gain amplifier (FGA) and a 1x,

2x, 4x, or 8x programmable gain amplifier (PGA). This allows accurate gain settings of 1x, 2x, 4x, 8x, 16x, 32x,

64x, or 128x through configuration of internal registers. Having an internal amplifier eliminates the need for

external amplifiers that are costly, space consuming, and difficult to calibrate.

• Excitation Current Sources (IB1 & IB2) - LMP90100/LMP90098

Two matched internal excitation currents, IB1 and IB2, can be used for sourcing currents to a variety of sensors.

The current range is from 100 µA to 1000 µA in steps of 100 µA.

Product Folder Links: LMP90100