1 Features

1• 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 nVRMS 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 VREF 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 builtin,

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.