Information

32 | Signal Chain Guide 2013 Texas Instruments
Data Converters
Analog-to-Digital Converters – Delta-Sigma ADCs
24-Bit Analog-to-Digital Converters for Temperature and Industrial Measurement
ADS1246, ADS1247, ADS1248
The ADS1246, ADS1247 and ADS1248 are highly integrated, precision, 24-bit analog-
to-digital converters (ADCs). The ADS1246/7/8 feature an onboard, low-noise program-
mable gain amplifier (PGA), a precision delta-sigma (
Δ∑) ADC with a single-cycle
settling digital filter and an internal oscillator. The ADS1247 and ADS1248 also provide
a built-in, low-drift voltage reference with 10mA output capacity and two matched
programmable current digital-to-analog converters (DACs). The ADS1246/7/8 provide a
complete front-end solution for temperature sensor applications including thermocou
-
ples, thermistors and RTDs.
Key Features
• Low-noisePGA:48nVatPGA=128
• Dataoutputratesupto2kSPS
• Single-cyclesettlingforalldatarates
• Simultaneous50/60Hzrejectionat20SPS
• 4diff/7single-endedinputs(ADS1248)
• 2diff/3single-endedinputs(ADS1247)
• Matchedcurrent-sourceDACs
• Verylowdriftinternalvoltage 
reference: 10 ppm/°C (max)
• Sensorburnoutdetection
• 4/8general-purposeI/Os(ADS1247/8)
• Internaltemperaturesensor
• PowersupplyandV
REF
monitoring
Applications
• Temperaturemeasurement
RTDs, thermocouples
and thermistors
•
Pressuremeasurement
• Industrialprocesscontrol
Get more information: www.ti.com/product/Part Number
(ADS1246, ADS1247, ADS1248)
ADS1247/1248 functional block diagram
Input
Mux
REFP1 REFN1 VREFOUT VREFCOM
REFP0/
GPIO0
REFN0/
GPIO1
Burnout
Detect
Burnout
Detect
DVDD
DGND
IEXC1AVSS
AIN0/IEXC
AIN1/IEXC
AIN2/IEXC/GPIO2
AIN3/IEXC/GPIO3
AIN4/IEXC/GPIO4
AIN5/IEXC/GPIO5
AIN6/IEXC/GPIO6
AIN7/IEXC/GPIO7
ADS1248 Only
SCLK
DIN
DRDY
DOUT/DRDY
CS
START
RESET
AVDD
IEXC2
Voltage
Reference
Internal Oscillator
Serial
Interface
and
Control
V
BIAS
GPIO
CLK
ADS1248 Only
ADS1247
ADS1248
PGA
System
Monitor
Adjustable
Digital
Filter
12-Bit
ADC
Dual
Current
DACs
ADS1248 Only
VREF Mux
Industrial, 14 kSPS, 24-Bit Analog-to-Digital Converter with Low-Drift Reference
ADS1259
The ADS1259 is a high-linearity, low-drift, 24-bit analog-to-digital converter (ADC)
designed for the needs of industrial process control, precision instrumentation and
other exacting applications. Combined with a signal amplifier (such as the PGA280-p.26),
a high-resolution, high-accuracy measurement system is formed that is capable of digitizing
a wide range of signals.
ADS1259 functional block diagram
Key Features
• Highperformance
INL: 0.4 ppm
Reference drift: 2 ppm/°C
Gain drift: 0.5 ppm/°C
Offsetdrift:0.05µV/°C
Noise:0.7µV
RMS
at 60 SPS
• 24-bits,nomissingcodes
• Outputdataratesfrom10SPSto
14 kSPS
•
Simultaneous50/60Hzrejection
at 10 SPS
•
Single-cyclesettling
• Internaloscillator
Applications
• Industrialprocesscontrol
• Scientificinstrumentation
• Testandmeasurement
Get more information: www.ti.com/product/ADS1259
Programmable
Digital Filter
2.5 V
Reference
Modulator
VREFP VREFN REFOUTAVDD DVDD
DGND
AVSS
AINP
AINN
XTAL2
XTAL1/CLKIN
Control
and
Serial
Interface
Clock
Generator
Out-of-Range
Detection
/
DRDY
SCLK
DIN
START
CS
DOUT
Calibration
Engine
f /8
CLK
SYNCOUT
ADS1259