1 Features

1• 24-bit, high-precision ADCs

– Offset drift: 1 nV/°C

– Gain drift: 0.5 ppm/°C

– Noise: 30 nVRMS (20 SPS, gain = 128)

– Linearity: 2 ppm

• CMOS PGA gain: 1 to 128

• Wide input voltage range: ±7 mV to ±5 V

• Data rate: 2.5 SPS to 40 kSPS

• 2.5-V reference: 2 ppm/°C

• Simultaneous 50-Hz and 60-Hz rejection mode

• Single-cycle settling mode

• Signal and reference monitors

• 5-V or ±2.5-V power supply

• Internal temperature sensor

• Cyclic redundancy check (CRC)

• Excitation current sources

• Sensor burn-out current sources

• Four general-purpose inputs/outputs (ADS1261)

• AC excitation for bridge sensors (ADS1261)

• 5-mm × 5-mm VQFN package

2 Applications

• PLC analog input modules

• Weigh scales and strain-gauge digitizers

• Temperature, pressure measurement

• Lab instrumentation

• Process analytics

3 Description

The ADS1260 and ADS1261 (ADS126x) are

precision, 40-kSPS, delta-sigma (ΔΣ) analog-to-digital

converters (ADCs) that include a programmable gain

amplifier (PGA). The devices also include a precision

voltage reference and internal fault monitors. The

sensor-ready ADCs give a high-accuracy, single-chip

solution for the most demanding measurements, for

example, weigh scales and resistance temperature

detectors (RTDs).

The ADCs contain an input signal multiplexer, a lownoise

PGA (with gains from 1 to 128), a 24-bit ΔΣ

modulator, a precision voltage reference, and a

programmable digital filter.

The high-impedance PGA inputs (1 GΩ) decrease

measurement error due to sensor loading. The

ADS1260 supports three differential or five singleended

inputs. The ADS1261 supports five differential

or ten single-ended inputs. The integrated current

sources simplify the measurement of RTDs.

The flexible digital filter is programmable for singlecycle

settled conversions, while supplying

simultaneous 50-Hz and 60-Hz line cycle rejection.

Signal and reference monitors, a temperature sensor,

and CRC data verification make data reliability better.

The ADS126x are pin compatible devices given in a

5-mm × 5-mm VQFN package and are specified

across the –40°C to +125°C temperature range.