SBASB61
August 2026
ADS124S18
PRODUCTION DATA
1
1
Features
2
Applications
3
Description
4
Pin Configuration and Functions
5
Specifications
5.1
Absolute Maximum Ratings
5.2
ESD Ratings
5.3
Recommended Operating Conditions
5.4
Thermal Information
5.5
Electrical Characteristics
5.6
Timing Requirements
5.7
Switching Characteristics
5.8
Timing Diagrams
5.9
Typical Characteristics
6
Parameter Measurement Information
6.1
Noise Performance
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Analog Inputs and Multiplexer
7.3.2
Programmable Gain Amplifier (PGA)
7.3.3
Voltage Reference
7.3.3.1
Internal Reference
7.3.3.2
External Reference
7.3.3.3
Reference Buffers
7.3.4
Power-Scalable Speed Modes
7.3.5
Clock Source
7.3.6
Delta-Sigma Modulator
7.3.7
Digital Filter
7.3.7.1
Sinc3 and Sinc4 Filters
7.3.7.2
Sinc4 + Sinc1 Filter
7.3.7.3
FIR Filter
7.3.7.4
50Hz and 60Hz Line Cycle Rejection
7.3.7.5
Digital Filter Latency
7.3.7.6
Global-Chop Mode
7.3.8
Excitation Current Sources (IDACs)
7.3.9
Burn-Out Current Sources (BOCS)
7.3.10
Bias Voltage Generator (VBIAS)
7.3.11
General Purpose IOs (GPIOs)
7.3.11.1
ALERT Output
7.3.11.2
FAULT Output
7.3.12
Offset and Gain Calibration Coefficients
7.3.13
Digital Comparator
7.3.14
System Monitors
7.3.14.1
Internal Short (Offset Calibration)
7.3.14.2
Internal Temperature Sensor
7.3.14.3
External Reference Voltage Readback
7.3.14.4
Power-Supply Readback
7.3.15
Monitors and Status Flags
7.3.15.1
Reset (RESETn flag)
7.3.15.2
AVDD Undervoltage Monitor (AVDD_UVn flag)
7.3.15.3
Reference Undervoltage Monitor (REF_UVn flag)
7.3.15.4
SPI CRC Fault (SPI_CRC_FAULTn flag)
7.3.15.5
Register Map CRC Fault (REG_MAP_CRC_FAULTn flag)
7.3.15.6
Internal Memory Fault (MEM_FAULTn flag)
7.3.15.7
Register Write Fault (REG_WRITE_FAULTn flag)
7.3.15.8
Digital Comparator Alert (COMP_ALERTn flag)
7.4
Device Functional Modes
7.4.1
Power-up and Reset
7.4.1.1
Power-On Reset (POR)
7.4.1.2
RESET Pin
7.4.1.3
Reset by Register Write
7.4.1.4
Reset by SPI Input Pattern
7.4.2
Operating Modes
7.4.2.1
Idle and Standby Mode
7.4.2.2
Power-Down Mode
7.4.2.3
Sequencer Mode
7.4.2.3.1
Configuring the Sequencer
7.4.2.3.2
Starting and Stopping the Sequencer (START/STOP bits and START pin)
7.4.2.3.3
Sequencer Status Bits
7.5
Programming
7.5.1
Serial Interface (SPI)
7.5.2
Serial Interface Signals
7.5.2.1
Chip Select (CS)
7.5.2.2
Serial Clock (SCLK)
7.5.2.3
Serial Data Input (SDI)
7.5.2.4
Serial Data Output/Data Ready (SDO/DRDY)
7.5.2.5
Data Ready (DRDY) Pin
7.5.3
Serial Interface Communication Structure
7.5.3.1
SPI Frame
7.5.3.2
STATUS Header
7.5.3.3
SPI CRC
7.5.4
Device Commands
7.5.4.1
No Operation (Read Conversion Data)
7.5.4.2
Read Register Command
7.5.4.3
Write Register Command
7.5.5
Continuous-Read Mode
7.5.5.1
Read Registers in Continuous-Read Mode
7.5.6
Daisy-Chain Operation
7.5.7
3-Wire SPI Mode
7.5.7.1
3-Wire SPI Mode Frame Re-Alignment
7.5.8
Monitoring for New Conversion Data
7.5.8.1
DRDY Pin or SDO/DRDY Pin Monitoring
7.5.8.2
Reading DRDY Bit and Conversion Counter
7.5.8.3
Clock Counting
7.5.9
DRDY Pin Behavior
7.5.10
Register Map CRC
7.5.11
Conversion Data Format
8
Register Map
8.1
Status and General Configuration Page Registers
8.2
Step Configuration Page Registers
9
Application and Implementation
9.1
Application Information
9.1.1
Serial Interface Connections
9.1.2
Unused Inputs and Outputs
9.1.3
Interfacing With Multiple Devices
9.1.4
Device Initialization and Starting the Sequencer
9.1.5
Sequencer Configuration Strategy Example
9.2
Typical Applications
9.2.1
Software-Configurable RTD Measurement Input
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.3
Application Performance Plots
9.2.1.4
Design Variant – 3-Wire RTD Measurement With Automatic Lead-Wire Compensation Using Two IDACs
9.2.2
Thermocouple Measurement With Cold-Junction Compensation Using a 2-wire RTD
9.2.3
Resistive Bridge Sensor Measurement With Temperature Compensation
9.2.4
Autonomous Power Supply Monitoring
9.2.4.1
Design Requirements
9.2.4.2
Detailed Design Procedure
9.3
Power Supply Recommendations
9.3.1
Power Supplies
9.3.2
Power-Supply Sequencing
9.3.3
Power-Supply Decoupling
9.4
Layout
9.4.1
Layout Guidelines
9.4.2
Layout Example
10
Device and Documentation Support
10.1
Related Documentation
10.2
Receiving Notification of Documentation Updates
10.3
Support Resources
10.4
Trademarks
10.5
Electrostatic Discharge Caution
10.6
Glossary
11
Revision History
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PBS|32
MPQF027A
Thermal pad, mechanical data (Package|Pins)
PBS|32
QFND381
Orderable Information
sbasb61_oa
9.3
Power Supply Recommendations