Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic

Looking for Iso1540 Ic? Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic is available at Zbotic with fast shipping across India.

Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic (AF-4903)

Sometimes you’ll find yourself with an I2C bus controller on one side, and an I2C bus device on the other and you gotta keep em (electrically) separated. Maybe because one is Earth-grounded, maybe because you’ve got some funky power monitoring setup, maybe you want to reduce noise.

Whatever it is, you can use the Adafruit ISO1540 Bidirectional I2C Isolator to add full electrical isolation between two sides of an I2C bus. The chip we use, the TI ISO1540 is fully bi-directional, supports up to 1 MHz clock rates, supports clock-stretching, works with 3 to 5V DC power or logic (separate on either side of course), with 2500 V-RMS isolation

Usage is easy – you get power/ground/clock/data breakout pads for each side as well as a matching STEMMA QT connector. Unlike our other QT boards, the two sides are obviously electrically isolated, which means each half must be powered! Check that the green LED is lit on both sides. Now send data over I2C and you’re good to go. We have 10K pullups on each side, from the I2C pins to the matching VCC for that side.

Features:

• Isolated bidirectional, I2C compatible, communication
• Supports up to 1-MHz operation
• 3-V to 5.5-V supply range
• Open-drain outputs With 3.5-mA Side 1 and 35-mA Side 2 sink current capability
• -40°C to +125°C operating temperature
• ±50-kV/μs transient immunity (Typical)
• HBM ESD protection of 4 kV on all pins; 8 kV on bus pins
• Safety-related certifications:
  • 4242-VPK isolation per DIN VDE V 0884-11:2017-01
  • 2500-VRMS isolation for 1 minute per UL 1577
  • CSA approval per IEC 60950-1 and IEC 62368-1 end equipment standards
  • CQC basic insulation per GB4943.1-2011

Package Includes:

1 x Adafruit ISO1540 Bidirectional I2C Isolator

About Iso1540 Ic

Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic is available at Zbotic, India’s trusted electronics and robotics store. Manufactured by Adafruit, this product is designed for hobbyists, students, and professionals working on electronics, robotics, and DIY projects.

Product Details

• Brand: Adafruit
• SKU: AI1758
• Category: USB Interface Module

Why Buy from Zbotic?

Zbotic offers a wide range of electronics components, development boards, sensors, and robotics parts. All products are quality-checked and shipped within 24 hours. Free shipping on qualifying orders. We offer COD (Cash on Delivery) and secure online payment options. Our customer support team is available to help with technical queries about Iso1540 Ic and other products.

Applications

Iso1540 Ic can be used in a variety of projects including Arduino projects, Raspberry Pi builds, drone assembly, 3D printing, IoT applications, and educational experiments. Whether you are a beginner or an advanced user, this component provides the reliability and performance you need. Order your Iso1540 Ic today and start building.

About Iso1540 Ic

Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic is available at Zbotic, India’s trusted electronics and robotics store. Manufactured by Adafruit, this product is designed for hobbyists, students, and professionals working on electronics, robotics, and DIY projects.

Product Details

• Brand: Adafruit
• SKU: AI1758
• Category: PCT and DC Power Connectors

Why Buy from Zbotic?

Zbotic offers a wide range of electronics components, development boards, sensors, and robotics parts. All products are quality-checked and shipped within 24 hours. Free shipping on qualifying orders. We offer COD (Cash on Delivery) and secure online payment options. Our customer support team is available to help with technical queries about Iso1540 Ic and other products.

Applications

Iso1540 Ic can be used in a variety of projects including Arduino projects, Raspberry Pi builds, drone assembly, 3D printing, IoT applications, and educational experiments. Whether you are a beginner or an advanced user, this component provides the reliability and performance you need. Order your Iso1540 Ic today and start building.

Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Overview

The Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT / Qwiic is a breakout board that provides full electrical isolation between two I2C buses. It uses the TI ISO1540 chip to support up to 1 MHz clock speeds while protecting devices from ground loops, voltage mismatches, and noise.

Key Features of Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT /

• Bi-directional isolation for SDA and SCL lines using TI ISO1540
• Operates from 3 V to 5.5 V on both sides – works with 3.3 V and 5 V systems
• Supports I2C clock frequencies up to 1 MHz, including clock-stretching
• STEMMA QT & Qwiic compatible connectors for plug-and-play wiring
• Wide operating temperature range: –40 °C to +125 °C
• Genuine Adafruit module, fast shipping across India from Zbotic

Applications and Use Cases

• Isolate sensitive measurement devices from digital I2C master controllers
• Prevent ground loops in multi-sensor agricultural or industrial setups
• Protect battery-powered or floating I2C peripherals in robotics projects
• Extend I2C bus over long cables without introducing noise
• Safeguard mixed-voltage environments when interfacing 3.3 V and 5 V devices

How to Use Adafruit ISO1540 Bidirectional I2C Isolator – STEMMA QT /

Connect your I2C master (e.g., microcontroller) to the “SIDE A” STEMMA QT or Qwiic port and your I2C device(s) to the “SIDE B” port. Provide 3–5.5 V power to both VCC_A and VCC_B pins, ensuring proper decoupling. The board automatically translates and isolates signals, so no additional configuration is needed—just plug in standard I2C cables and begin communication.

Why Buy from Zbotic?

• Genuine Products: All items sourced from authorized distributors
• Fast Shipping: Orders ship within 24 hours with tracking (non backordered products)
• Free Shipping: Free delivery on qualifying orders
• COD Available: Cash on Delivery, UPI, cards, net banking
• Technical Support: Expert help for setup and troubleshooting
• Easy Returns: Hassle-free replacement for defective products

Frequently Asked Questions

Does the ISO1540 support clock-stretching?

Yes. The TI ISO1540 chip fully supports I2C clock-stretching on both sides, ensuring compatibility with devices that hold the SCL line low for internal processing.

Can I use different supply voltages on each side?

Absolutely. Each side (VCC_A and VCC_B) accepts 3 V to 5.5 V independently, so you can isolate a 3.3 V microcontroller from a 5 V sensor without level-shifting issues.

How do I connect this module to my Arduino or Raspberry Pi?

Simply plug a STEMMA QT or Qwiic cable into the matching port on the ISO1540 board and the other end into your Arduino/Raspberry Pi’s I2C header. Repeat on the device side, supply power to both VCC rails, and you’re ready to communicate.