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ISO1211

ACTIVE

Single-channel Isolated 24-V to 60-V digital input receiver for digital input modules

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Data sheet

ISO1211

ACTIVE
Data sheet Order now

Product details

Rating Catalog Isolation rating Basic Number of channels 1 Forward/reverse channels 1/0 Data rate (max) (Mbps) 4 Working isolation voltage (VIOWM) (Vrms) 400 Surge isolation voltage (VIOSM) (VPK) 5200 Transient isolation voltage (VIOTM) (VPK) 3600 Withstand isolation voltage (VISO) (Vrms) 2500 CMTI (min) (kV/µs) 25 Operating temperature range (°C) -40 to 125 Propagation delay time (typ) (µs) 0.14
Rating Catalog Isolation rating Basic Number of channels 1 Forward/reverse channels 1/0 Data rate (max) (Mbps) 4 Working isolation voltage (VIOWM) (Vrms) 400 Surge isolation voltage (VIOSM) (VPK) 5200 Transient isolation voltage (VIOTM) (VPK) 3600 Withstand isolation voltage (VISO) (Vrms) 2500 CMTI (min) (kV/µs) 25 Operating temperature range (°C) -40 to 125 Propagation delay time (typ) (µs) 0.14
SOIC (D) 8 29.4 mm² (4.9 mm × 6 mm)
  • Compliant to IEC 61131-2; Type 1, 2, 3 characteristics for 24V isolated digital inputs
  • Supports 9V to 300V DC and AC digital input designs using external resistors
  • Accurate Current Limit for Low-Power Dissipation:
    • 2.2mA to 2.47mA for Type 3
    • Adjustable up to 6.5mA
  • Eliminates the need for field-side power supply
  • High input-voltage range with reverse polarity protection: ±60V
  • Wire-break detection (refer to TIDA-01509)
  • Configurable as sourcing or sinking input
  • High data rates: up to 4Mbps
  • Enable pin to multiplex output signals
  • High transient immunity: ±70kV/µs CMTI
  • Wide supply range (VCC1): 2.25V to 5.5V
  • Ambient temperature range: –40°C to +125°C
  • Compact package options:
    • Single-channel ISO1211, SOIC-8
    • Dual-channel ISO1212, SSOP-16
  • Functional safety capable
    • Documentation available to aid functional safety system design: ISO1211, ISO1212
  • Compliant to IEC 61131-2; Type 1, 2, 3 characteristics for 24V isolated digital inputs
  • Supports 9V to 300V DC and AC digital input designs using external resistors
  • Accurate Current Limit for Low-Power Dissipation:
    • 2.2mA to 2.47mA for Type 3
    • Adjustable up to 6.5mA
  • Eliminates the need for field-side power supply
  • High input-voltage range with reverse polarity protection: ±60V
  • Wire-break detection (refer to TIDA-01509)
  • Configurable as sourcing or sinking input
  • High data rates: up to 4Mbps
  • Enable pin to multiplex output signals
  • High transient immunity: ±70kV/µs CMTI
  • Wide supply range (VCC1): 2.25V to 5.5V
  • Ambient temperature range: –40°C to +125°C
  • Compact package options:
    • Single-channel ISO1211, SOIC-8
    • Dual-channel ISO1212, SSOP-16
  • Functional safety capable
    • Documentation available to aid functional safety system design: ISO1211, ISO1212

The ISO1211 and ISO1212 devices are isolated 24V to 60V digital input receivers, compliant to IEC 61131-2 Type 1, 2, and 3 characteristics. These devices enable 9V to 300V DC and AC digital input modules in programmable logic controllers (PLCs), motor-control, grid infrastructure, and other industrial applications. Unlike traditional optocoupler designs with discrete, imprecise current limiting circuitry, the ISO121x devices provide a simple, low-power design with an accurate current limit to enable the design of compact and high-density I/O modules. These devices do not require field-side power supply and are configurable as sourcing or sinking inputs.

The ISO121x devices operate over the supply range of 2.25V to 5.5V, supporting 2.5V, 3.3V, and 5V controllers. A ±60V input tolerance with reverse polarity protection helps provide the input pins are protected in case of faults with negligible reverse current. These devices support up to 4Mbps data rates passing a minimum pulse width of 150ns for high-speed operation. The ISO1211 device is designed for applications that require channel-to-channel isolation and the ISO1212 device is designed for multichannel space-constrained designs.

The ISO121x devices reduce component count, simplify system design, improve performance, and reduce board temperatures compared to traditional designs. For details, refer to the How To Simplify Isolated 24V PLC Digital Input Module Designs TI TechNote, How To Improve Speed and Reliability of Isolated Digital Inputs in Motor Drives TI TechNote, and How to Design Isolated Comparators for ±48V, 110V and 240V DC and AC Detection TI TechNote.

The ISO1211 and ISO1212 devices are isolated 24V to 60V digital input receivers, compliant to IEC 61131-2 Type 1, 2, and 3 characteristics. These devices enable 9V to 300V DC and AC digital input modules in programmable logic controllers (PLCs), motor-control, grid infrastructure, and other industrial applications. Unlike traditional optocoupler designs with discrete, imprecise current limiting circuitry, the ISO121x devices provide a simple, low-power design with an accurate current limit to enable the design of compact and high-density I/O modules. These devices do not require field-side power supply and are configurable as sourcing or sinking inputs.

The ISO121x devices operate over the supply range of 2.25V to 5.5V, supporting 2.5V, 3.3V, and 5V controllers. A ±60V input tolerance with reverse polarity protection helps provide the input pins are protected in case of faults with negligible reverse current. These devices support up to 4Mbps data rates passing a minimum pulse width of 150ns for high-speed operation. The ISO1211 device is designed for applications that require channel-to-channel isolation and the ISO1212 device is designed for multichannel space-constrained designs.

The ISO121x devices reduce component count, simplify system design, improve performance, and reduce board temperatures compared to traditional designs. For details, refer to the How To Simplify Isolated 24V PLC Digital Input Module Designs TI TechNote, How To Improve Speed and Reliability of Isolated Digital Inputs in Motor Drives TI TechNote, and How to Design Isolated Comparators for ±48V, 110V and 240V DC and AC Detection TI TechNote.
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Technical documentation

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Top documentation Type Title Format options Date
* Data sheet ISO121x Isolated 24V to 60V Digital Input Receivers for Digital Input Modules datasheet (Rev. G) PDF | HTML Feb 12, 2025
Certificate VDE Certificate for Basic Isolation for DIN EN IEC 60747-17 (Rev. AA) Jun 11, 2026
Certificate TUV Certificate for Isolation Devices (Rev. M) May 7, 2026
Certificate UL Certificate of Compliance File E181974 Vol 4 Sec 6 (Rev. S) May 7, 2026
Certificate CQC Certificate for ISOxxD (Rev. B) Aug 19, 2025
Application brief How To Simplify Isolated 24V PLC Digital Input Module Designs (Rev. D) PDF | HTML Jun 30, 2025
Application brief Space-Saving Design Techniques for Multichannel High-Voltage Digital Input Modules (Rev. C) PDF | HTML Nov 11, 2024
Functional safety information ISO1211 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA PDF | HTML Sep 12, 2024
Certificate CSA Certificate for ISO1211xD Mar 22, 2023
Technical article Understand and apply safety-limiting values for digital isolators PDF | HTML Jan 20, 2021
Application brief How to Design Isolated Digital Input Modules for Surge Immunity Mar 31, 2020
Technical article Solving lifetime and temperature challenges in AC motor drives with capacitive-bas PDF | HTML Nov 1, 2019
Technical article Optocouplers and silicon-based galvanic isolation technology – how do they work? PDF | HTML Oct 28, 2019
White paper How Capacitive Isolation Solves Key Challenges in AC Motor Drives Aug 23, 2019
Application brief An Isolated 24 V Power Supply Window Monitor Aug 1, 2019
Technical article What are isolated digital inputs? PDF | HTML Mar 8, 2019
Application brief How to Design Isolated Comparators for ±48V, 110V and 240V DC and AC Detection (Rev. A) Mar 14, 2018
Application note ISO121x Threshold Calculator for 9V to 300V DC and AC Voltage Detection Mar 1, 2018
Application brief How to Improve Speed and Reliability of Isolated Digital Inputs in Motor Drives Dec 16, 2017
Analog design Journal How to use isolation to improve ESD, EFT and surge immunity in industrial system Jul 24, 2017

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

ISO1211EVM — Evaluation module for the ISO1211 isolated digital input receiver

The ISO1211EVM is an evaluaiton module (EVM) used to evaluate the ISO1211 isolated industrial reciever that can receive a 9-V to 60-V field input and provide an isolated digital output. The EVM accomodates two ISO1211 devices showcasing 2 channel functionality. The EVM features enough test (...)
User guide: PDF
Supported products & hardware
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Simulation model

ISO1211 PSpice Transient Model (Rev. C)

SLLM383C.ZIP (117 KB) - PSpice model
Supported products & hardware
Simulation model

ISO1211 TINA-TI Transient Reference Design (Rev. A)

SLLM390A.TSC (1859 KB) - TINA-TI reference design
Supported products & hardware
Simulation model

ISO1211 TINA-TI Transient Spice Model (Rev. A)

SLLM389A.ZIP (12 KB) - TINA-TI Spice model
Supported products & hardware
Simulation model

ISO121X IBIS Model (Rev. B)

SLLM372B.ZIP (52 KB) - IBIS model
Supported products & hardware
Reference design

TIDA-01508 — Sub 1-W, 16-Channel, Isolated Digital Input Module Reference Design

This reference design shows a compact implementation of 16 isolated digital input channels using TI's ISO121x devices. The design works without an isolated supply and supports up to 100-kHz input signals (200-kbit) per channel. All 16 channels consume less than 1-W input power combined, which (...)
Supported products & hardware
Reference design

TIDA-01509 — Broken Wire Detection Using An Optical Switch Reference Design

This reference design shows a compact implementation of 16 isolated digital input channels using TI's ISO121x devices. The design is split into two groups of eight channels each. A broken wire detection can be executed using only one additional optical switch for each channel or two optical (...)
Supported products & hardware
Reference design

TIDA-01599 — TÜV SÜD-assessed safe torque off (STO) reference design for industrial drives (IEC 61800-5-2)

This reference design outlines a safe torque off (STO) subsystem for a three-phase inverter with CMOS input isolated IGBT gate drivers. The STO subsystem employs a dual-channel architecture (1oo2) with a hardware fault tolerance of 1 (HFT=1). It is implemented following a de-energize trip concept. (...)
Supported products & hardware
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