P82B715 I2C Bus Extender - Overview
P82B715 I2C Bus Extender
The P82B715 I2C Bus Extender breakout board is based on the NXP/TI P82B715 chip, a bidirectional I²C bus buffer that extends the range and capacitance limits of standard I²C communication. It drives 10× lower-impedance bus wiring, so the long cable's capacitance never loads your microcontroller's bus. That's what lets I²C signals travel over twisted-pair runs of up to 50 meters and drive wiring capacitance of up to 3000 pF, well beyond the standard 400 pF I²C limit.
The board connects to your microcontroller via Qwiic (3.3V I2C) on the local side. An onboard boost converter steps 3.3V up to 5V to power the P82B715 buffer, and an onboard level shifter handles the 3.3V ↔ 5V translation transparently. The extended (remote) side is exposed via a screw terminal, making it easy to connect long cables or wired I²C runs.
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Key features
- Function: Bidirectional I²C bus buffer and extender
- Bus wiring: Drives 10× lower-impedance wiring, raising the usable wiring capacitance from 400 pF to 3000 pF
- Local side: Supports up to 400 pF bus capacitance (standard I²C)
- Extended side: Supports up to 3000 pF bus capacitance
- Max cable length: Up to 50 m over twisted-pair cable
- I²C speed: Standard-mode (100 kHz) over long runs; faster clocks work over shorter cable
- Power input: 3.3V via Qwiic (onboard boost converter generates 5V for the buffer)
- Level shifting: Onboard 3.3V ↔ 5V level shifter
- ESD protection: Onboard ESD protection on the extended bus side
- Local connector: 2 × Qwiic ports (3.3V I2C, plug-and-play)
- Extended connector: Screw terminal for long-cable connections
- Power LED: Onboard purple power indicator LED
You may also need
Qwiic cable
Qwiic compatible cables with connectors on both ends, available in various lengths.