Information

62 | Signal Chain Guide 2013 Texas Instruments
Data Converters
Analog Front Ends—Sensor AFEs
Multi-Channel, Low-Power 24-Bit Sensor AFE with True Continuous Background Calibration
LMP90100
The LMP90100 is a highly integrated, multi-channel, low-power 24-bit sensor AFE. The
device features a precision, 24-bit Sigma Delta Analog-to-Digital Converter (ADC) with
a low-noise programmable gain amplifier and a fully differential high impedance analog
input multiplexer. A true continuous background calibration feature allows calibration at all
gains and output data rates without interrupting the signal path. The background calibra
-
tion feature essentially eliminates gain and offset errors across temperature and time,
pr
oviding measurement accuracy without sacrificing speed and power consumption.
Get more information: www.ti.com/product/LMP90100
LMP90100 functional block diagram
VA
Internal
CLK
Ext. Clk
Detect
CLK/
XIN
XOUT
CSB
SCLK
SDI
SDO/DRDYB
VREFP1
VREFN1
VIN0
VIN1
VIN2
VIN3
VIN4
VIN5
IB1
IB2
VA
EXC.
Current
GND
GPIO
D0
D6/
DRDYB
Open/Short
Sensor Diag.
VIO
EXC.
Current
Serial I/F
Control
&
Calibration
Data Path
POR
24-Bit
∑
Δ
Module
Digital
Filter
CLK
MUX
VIN6/VREFP2
MUX
Chip Configurable
Channel Configurable
Fixed
LMP90xxx
Background
Calibration
PGA
1x, 2x,
4x, 8x
VIN7/VREFN2
V
REF
FGA
16x
Input MUX
LMP90100/
LMP90098 only
LMP90100/
LMP90099 only
BUFF
Digital Sensor AFEs
Device Description
ADC Res.
(Bits)
Sample
Rate
(ksps)
Input
Chs.
Supply
Voltage
Range (V)
Supply
Current
(mA)
Temp.
Range
(°C)
Current
Sources
Calib-
ration
HiRel
Avail. Package Price*
LMP90100 Multi-Channel, Low Power 24-Bit Sensor AFE with
True Continuous Background Calibration
24 0.215 7 2.85 to 5.5 0.4 –40 to
125
Y Y N TSSOP-28 3.33
LMP90097 Multi-Channel, Low Power 24-Bit Sensor AFE with
True Continuous Background Calibration
24 0.215 4 2.85 to 5.5 0.4 –40 to
125
N Y N TSSOP-28 3.17
LMP90098 Multi-Channel, Low Power 24-Bit Sensor AFE with
True Continuous Background Calibration
24 0.215 4 2.85 to 5.5 0.4 –40 to
125
Y Y N TSSOP-28 3.01
LMP90099 Multi-Channel, Low Power 24-Bit Sensor AFE with
True Continuous Background Calibration
24 0.215 7 2.85 to 5.5 0.4 –40 to
125
N Y N TSSOP-28 2.86
LMP90077 Multi-Channel, Low-Power 16-Bit Sensor AFE with
True Continuous Background Calibration
16 0.215 4 2.85 to 5.5 0.4 –40 to
125
N Y N TSSOP-28 2.33
LMP90078 Multi-Channel, Low-Power 16-Bit Sensor AFE with
True Continuous Background Calibration
16 0.215 4 2.85 to 5.5 0.4 –40 to
125
Y Y N TSSOP-28 2.45
LMP90079 Multi-Channel, Low-Power 16-Bit Sensor AFE with
True Continuous Background Calibration
16 0.215 7 2.85 to 5.5 0.4 –40 to
125
N Y N TSSOP-28 2.58
LMP90080 Multi-Channel, Low Power 16-Bit Sensor AFE with
True Continuous Background Calibration
16 0.215 7 2.85 to 5.5 0.4 –40 to
125
Y Y N TSSOP-28 2.72
Analog Sensor AFEs
Device Description
ADC Res.
(Bits)
Sample Rate
(ksps)
Input
Chs.
Supply Voltage
Range (V)
Supply Current
(mA)
Temp. Range
(°C) Package Price*
LMP91000 Configurable AFE Potentiostat for Low-Power
Chemical Sensing Applications
1 2.7 to 5.25 0.01 –40 to 85 Y N LLP-14 2.80
LMP91050 Configurable AFE for NDIR Based Sensors 1 2.7 to 5.5 3.7 –40 to 105 N N MSOP-10 1.32
LMP91051 Configurable AFE for NDIR Sensing Applications 2 2.7 to 5.5 3.6 –40 to 105 — N TSSOP-14 1.45
LMP91200 Configurable AFE for Low-Power pH Sensing
Applications
1 1.8 to 5.5 0.05 –40 to 125 Ext N TSSOP-16 3.90
LMP91002 Configurable AFE Potentiostat for Zero-Bias Sensing
Applications
1 2.7 to 3.6 0.01 –40 to 85 N N LLP-14 1.80
Key Features
• 24-bitlow-powerSigmaDeltaADC
• Truecontinuousbackgroundcalibration
at all gains
•
In-placesystemcalibrationusing
expected value programming
•
Low-noiseprogrammablegain(1x-128x)
• Continuousbackgroundopen/shortand
out of range sensor diagnostics
•
Eightoutputdatarates(ODR)with
single-cycle settling
•
Twomatchedexcitationcurrentsources
from100µAto1000µA
• Sevengeneralpurposeinput/outputpins
• Chopper-stabilizedbufferforlowoffset
• SPI4/3-wirewithCRCdatalinkerror
detection
• 50to60HzlinerejectionatODR≤13.42SPS
• IndependentgainandODRselectionper
channel
• SupportedbyWEBENCH
®
sensor AFE
designer
• Automaticchannelsequencer
Applications
• Fieldtransmitter—pressureand
temperature sensors
•
Medicalequipment
• Programmablelogiccontroller
*Suggested resale price in U.S. dollars in quantities of 1,000. See www.ti.com/hirel for HiRel options. New products are listed in bold red.