{"title":"Adafruit LTC4311 I2C Extender / Active Terminator - STEMMA QT / Qwiic","handle":"adafruit-ltc4311-i2c-extender-active-terminator-stemma-qt-qwiic","url":"/products/adafruit-ltc4311-i2c-extender-active-terminator-stemma-qt-qwiic","description":"The Adafruit LTC4311 Active Terminator solves a common I2C problem: running long cables. Standard I2C is designed for short PCB-level connections, but cable capacitance and resistance degrade signals over distance. The LTC4311 watches the SDA and SCL lines and actively boosts pull-up current, restoring clean square-wave signals even over multi-metre cables.\n\nSimply plug this board into your I2C bus at the start of the chain — no firmware, software, or configuration needed. In testing, it ran a 400 kHz OLED over 3 metres of phone wire with ease, and even drove a BME680 sensor over 30 metres of Ethernet cable at 100 kHz (~3000 pF round trip).\n\nKey Features\n\n\nActive I2C Termination – Boosts pull-up current on SDA and SCL for clean signal edges over long cables\n\nWide Voltage Range – Works with any bus voltage from 1.6 V to 5.5 V\n\nUp to 400 kHz – Supports standard and fast I2C clock speeds\n\nCable Capacitance up to 4000 pF – Handles very long cable runs\n\nZero Configuration – No firmware, software, or resistor tuning required; just plug in and go\n\nSTEMMA QT / Qwiic – Solderless I2C connectors on both sides for easy daisy-chaining\n\n\nIdeal For\n\nRunning I2C sensors over long cables (1–30+ metres)\nFixing unreliable I2C communication on extended buses\nRemote sensor installations connected by phone wire or Ethernet cable\nAny I2C project where cable capacitance is degrading signal quality\n\n\nPackage Contents\n\n1× Adafruit LTC4311 I2C Extender / Active Terminator (STEMMA QT)\n\n\nResources\n\nWhat is STEMMA QT?\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":3832,"title":"Default Title","sku":"AF-4756","price":14.63,"compare_at_price":0.0,"on_sale":false,"in_stock":true,"available_quantity":103,"option1":"Default Title"}]}