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ADS1246、ADS1247和ADS1248是一款精确的24位模拟至数字转换器(ADC)，它们拥有集成的多种功能，目的是降低系统成本和组件数量，特别适用于传感器测量应用。这些设备集成了低噪声的可编程增益放大器(PGA)、高精度的差分模拟至数字转换器、具有单周期稳定功能的数字滤波器，以及一个内部振荡器。ADS1247和ADS1248还内置了低漂移的电压参考和两组匹配的可编程激励电流源(IDACs)。 ADS1246、ADS1247和ADS1248的主要特点包括： 1. 可编程数据率高达2kSPS。 2. 所有数据率下实现单周期稳定。 3. 同时实现20SPS时的50 Hz和60 Hz信号干扰抑制。 4. ADS1248有8路，ADS1247有4路独立可选输入的模拟多路复用器。 5. 低噪声PGA，当PGA增益为128时，噪声为48nVRMS。 6. 内置的双匹配可编程激励电流源。 7. 内部2.048V参考电压具有低漂移特性，最大为10ppm/°C。 8. 内置传感器断线检测功能。 9. ADS1247和ADS1248提供4或8个通用IO。 10. 内置温度传感器。 11. ADS1247和ADS1248监测电源和参考电压。 12. 具备自校准和系统校准功能。 13. SPI兼容的串行接口。 14. 模拟供电支持单极性(2.7V到5.25V)和双极性(±2.5V)操作。 15. 数字供电：2.7V到5.25V。 ADS1246、ADS1247和ADS1248适用于以下应用： 1. 温度传感器测量。 2. 压力测量。 3. 流量计。 4. 工厂自动化和过程控制。 ADS1246、ADS1247和ADS1248的描述：这三款设备是精密的24位ADC，包含了许多集成的功能以减少传感器测量应用中的系统成本和组件数量。这些设备的特性包括一个低噪声PGA、一个具有单周期稳定数字滤波器的高精度ΔΣADC，以及一个内部振荡器。ADS1247和ADS1248还提供了内置的低漂移电压参考和两组匹配的可编程激励电流源(IDACs)。 ADS1246、ADS1247和ADS1248都具备单周期稳定功能的数字滤波器，这使得在快速通道切换时能够实现快速稳定。输入多路复用器支持ADS1248的四个差分输入，ADS1247的两个差分输入以及ADS1246的一个差分输入。此外，多路复用器集成了传感器检测、热电偶、系统监测和通用数字IO(ADS1247和ADS1248)。PGA提供了可选的增益高达128V/V。这些特点为温度传感器测量应用(包括热电偶、热敏电阻、电阻温度检测器(RTDs)和其他小信号测量(如电阻桥传感器)提供了一个完整的前端解决方案。该设备支持的温度传感器测量应用包括温度传感器、压力测量、流量计、工厂自动化和过程控制等领域。 ADS1246、ADS1247和ADS1248的电源和参考电压监测功能确保了电源和参考电压的稳定性。该系列设备还提供了自校准和系统校准功能，以提高测量的精确度。通过SPI兼容的串行接口，可以方便地与微控制器等进行通信。在模拟供电方面，支持单极性(2.7V到5.25V)和双极性(±2.5V)操作，数字供电范围为2.7V到5.25V。

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AIN0/IEXC

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Burnout

Detect

Burnout

Detect

3rd Order

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Modulator

AVDD REFP1 REFN1 DVDD

ADS1247

ADS1248

SCLK

DIN

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DOUT/DRDY

START

RESET

DGNDCLKAVSS

Input

Mux

BIAS

PGA

Adjustable

Digital

Filter

Serial

Interface

And

Control

Internal Oscillator

AIN2/IEXC/GPIO2

AIN3/IEXC/GPIO3

AIN4/IEXC/GPIO4

AIN5/IEXC/GPIO5

AIN6/IEXC/GPIO6

AIN7/IEXC/GPIO7

REFP0/

GPIO0

REFN0/

GPIO1

VREF Mux

Voltage

Reference

GPIO

System

Monitor

VREFOUT VREFCOM

IEXC1 IEXC2

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Mux

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Adjustable

Digital

Filter

Serial

Interface

And

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Product

Folder

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Design

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.

ADS1246

ADS1247

ADS1248

SBAS426H –AUGUST 2008–REVISED MARCH 2016

ADS124x 24-Bit, 2-kSPS, Analog-To-Digital Converters With

Programmable Gain Amplifier (PGA) For Sensor Measurement

1 Features

• Programmable Data Rates Up to 2 kSPS

• Single-Cycle Settling for All Data Rates

• Simultaneous 50-Hz and 60-Hz Rejection at 20

SPS

• Analog Multiplexer With 8 (ADS1248) and 4

(ADS1247) Independently Selectable Inputs

• Low-Noise PGA: 48 nV

RMS

at PGA = 128

• Dual-Matched Programmable Excitation Current

Sources

• Low-Drift Internal 2.048-V Reference:

10 ppm/°C (Maximum)

• Sensor Burn-Out Detection

• 4 or 8 General-Purpose I/Os (ADS1247,

ADS1248)

• Internal Temperature Sensor

• Power Supply and V

REF

Monitoring (ADS1247,

ADS1248)

• Self and System Calibration

• SPI™-Compatible Serial Interface

• Analog Supply: Unipolar (2.7 V to 5.25 V) and

Bipolar (±2.5 V) Operation

• Digital Supply: 2.7 V to 5.25 V

2 Applications

• Temperature Sensor Measurements:

– RTDs, Thermocouples, and Thermistors

• Pressure Measurements

• Flow Meters

• Factory Automation and Process Controls

3 Description

The ADS1246, ADS1247, and ADS1248 devices are

precision, 24-bit analog-to-digital converters (ADCs)

that include many integrated features to reduce

system cost and component count for sensor

measurement applications. The devices feature a

low-noise, programmable gain amplifier (PGA), a

precision delta-sigma (ΔΣ) ADC with a single-cycle

settling digital filter, and an internal oscillator. The

ADS1247 and ADS1248 devices also provide a built-

in, low-drift voltage reference, and two matched

programmable excitation current sources (IDACs).

An input multiplexer supports four differential inputs

for the ADS1248, two for the ADS1247, and one for

the ADS1246. In addition, the multiplexer integrates

sensor burn-out detection, voltage bias for

thermocouples, system monitoring, and general

purpose digital I/Os (ADS1247 and ADS1248). The

PGA provides selectable gains up to 128 V/V. These

features provide a complete front-end solution for

temperature sensor measurement applications

including thermocouples, thermistors, and resistance

temperature detectors (RTDs) and other small signal

measurements including resistive bridge sensors.

The digital filter settles in a single cycle to support

fast channel cycling when using the input multiplexer

and provides data rates up to 2 kSPS. For data rates

of 20 SPS or less, both 50-Hz and 60-Hz interference

are rejected by the filter.

Device Information

(1)

PART NUMBER PACKAGE BODY SIZE (NOM)

ADS1246 TSSOP (16) 5.00 mm × 4.40 mm

ADS1247 TSSOP (20) 6.50 mm × 4.40 mm

ADS1248 TSSOP (28) 9.70 mm × 4.40 mm

(1) For all available packages, see the orderable addendum at

the end of the datasheet.

Simplified Schematic

ADS1246

ADS1247

ADS1248

SBAS426H –AUGUST 2008–REVISED MARCH 2016

www.ti.com

Product Folder Links: ADS1246 ADS1247 ADS1248

Table of Contents

1 Features.................................................................. 1

2 Applications ........................................................... 1

3 Description ............................................................. 1

4 Revision History..................................................... 2

5 Device Comparison Table..................................... 4

6 Pin Configuration and Functions......................... 5

7 Specifications......................................................... 7

7.1 Absolute Maximum Ratings ...................................... 7

7.2 ESD Ratings.............................................................. 7

7.3 Recommended Operating Conditions....................... 8

7.4 Thermal Information.................................................. 8

7.5 Electrical Characteristics........................................... 9

7.6 Timing Requirements.............................................. 11

7.7 Switching Characteristics........................................ 11

7.8 Typical Characteristics............................................ 13

8 Parameter Measurement Information ................ 21

8.1 Noise Performance ................................................. 21

9 Detailed Description............................................ 24

9.1 Overview ................................................................. 24

9.2 Functional Block Diagram ....................................... 24

9.3 Feature Description................................................. 25

9.4 Device Functional Modes........................................ 36

9.5 Programming........................................................... 41

9.6 Register Maps......................................................... 50

10 Application and Implementation........................ 70

10.1 Application Information.......................................... 70

10.2 Typical Applications .............................................. 76

10.3 Do's and Don'ts..................................................... 86

11 Power-Supply Recommendations ..................... 88

11.1 Power-Supply Sequencing.................................... 88

11.2 Power-Supply Decoupling..................................... 88

12 Layout................................................................... 89

12.1 Layout Guidelines ................................................. 89

12.2 Layout Example .................................................... 90

13 Device and Documentation Support ................. 91

13.1 Documentation Support ........................................ 91

13.2 Related Links ........................................................ 91

13.3 Community Resources.......................................... 91

13.4 Trademarks........................................................... 91

13.5 Electrostatic Discharge Caution............................ 91

13.6 Glossary................................................................ 91

14 Mechanical, Packaging, and Orderable

Information ........................................................... 91

4 Revision History

NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

Changes from Revision G (October 2011) to Revision H Page

• Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation

section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and

Mechanical, Packaging, and Orderable Information section .................................................................................................. 1

• Updated Features and Description sections to include use in applications other than temperature measurement .............. 1

• Edited Device Comparison Table to include ADS1146, ADS1147, and ADS1148; changed title, deleted footnote ............. 4

• Merged all Pin Functions into one table, changed IOUT1 and IOUT2 to IEXC1 and IEXC2 to match figures...................... 6

• Changed compliance voltage for excitation current sources in Electrical Characteristics, now refers to Figure 41 and

Figure 42; changed initial error and initial mismatch to absolute error and absolute mismatch ............................................ 9

• Re-ordered elements in Timing Requirements tables, changed timing references to t

CLK

................................................... 11

• Changed order of Typical Characteristics curves to match order in Electrical Characteristics table................................... 13

• Added cross-reference for Equation 1 in Noise Performance section ................................................................................. 21

• Corrected values in Table 2.................................................................................................................................................. 22

• Modified Low-Noise PGA section to add more detail; added Table 7; added PGA Common-Mode Voltage

Requirements and PGA Common-Mode Voltage Calculation Example sections ................................................................ 26

• Added f

CLK

MOD

column to Table 9 ....................................................................................................................................... 30

• Added cross-reference for Equation 15 to Power-Supply Monitor section........................................................................... 35

• Added cross-reference for Equation 16 to External Voltage Reference Monitor section..................................................... 35

• Added Device Functional Modes section ............................................................................................................................. 36

• Corrected values in Table 15 to remove extra 0 in 800000h ............................................................................................... 40

• Added text to Chip Select section to say that SCLK will force DRDY high, even with CS high........................................... 41

• Added text to Data Output and Data Ready section to say that stop read data continuous mode is not compatible

with DRDY MODE set to 1 ................................................................................................................................................... 42

• Modified Figure 74 and Figure 75 to better show DIN transitions with respect to SCLK; replaced Figure 76 to better

ADS1246

ADS1247

ADS1248

www.ti.com

SBAS426H –AUGUST 2008–REVISED MARCH 2016

Product Folder Links: ADS1246 ADS1247 ADS1248

Revision History (continued)

show full command and DRDY/DOUT falling with NOP....................................................................................................... 43

• Added more infomation to Data Format section; added Figure 77 ...................................................................................... 44

• Added cross-reference for Figure 78 to Commands section................................................................................................ 45

• Modified Figure 78 to include CS status through SLEEP and WAKEUP command............................................................ 46

• Updated Figure 79 and Figure 80 to show start of command execution ............................................................................. 46

• Added cross-reference for Figure 83 to Commands section................................................................................................ 47

• Removed figure for SDATAC (Stop Read Data Continuous) command .............................................................................. 47

• Updated Figure 85 to show MUX1 as the start of the data byte for the given command and register location................... 48

• Updated Figure 86 to show start of calibration timing.......................................................................................................... 49

• Updated Register Maps section to new format .................................................................................................................... 50

• Updated Application Information section. Included new typical applications for Ratiometric 3-Wire RTD

Measurement System and K-Type Thermocouple Measurement (–200°C to +1250°C) with Cold-Junction

Compensation....................................................................................................................................................................... 70

• Updated Figure 112 and Figure 113 to better show timing information ............................................................................... 74

• Removed Hardware-Compensated 3-Wire RTD Measurement application section ............................................................ 76

Changes from Revision F (June 2011) to Revision G Page

• Added Figure 35 .................................................................................................................................................................. 17

• Added Figure 41 and Figure 42............................................................................................................................................ 18

Changes from Revision E (December, 2010) to Revision F Page

• Added footnote to Full-scale input voltage specification in Electrical Characteristics table ................................................... 8

• Added test condition for INL parameter of Electrical Characteristics..................................................................................... 9

• Added t

CSPW

to minimum specification in Timing Characteristics for Figure 1...................................................................... 11

• Updated Figure 1 to show t

CSPW

timing ................................................................................................................................ 12

• Corrected grid and axis values for Figure 29 ....................................................................................................................... 16

• Corrected grid and axis values for Figure 30 ....................................................................................................................... 16

• Updated Figure 51................................................................................................................................................................ 25

• Added details to Bias Voltage Generation section ............................................................................................................... 34

• Corrected Table 14............................................................................................................................................................... 39

• Added details to Calibration section ..................................................................................................................................... 39

• Added Equation 18 to Calibration section ............................................................................................................................ 39

• Added section to Calibration Commands ............................................................................................................................. 40

• Added details to Digital Interface section ............................................................................................................................. 43

• Added Restricted command space to Table 19 ................................................................................................................... 45