4-channel I2C-safe Bi-directional Logic Level Converter [BSS138]

This bi-directional logic level converter from Adafruit uses 4× BSS138 FETs with 10K pull-up resistors to safely shift signals between different voltage levels. Unlike many level shifters, this design is fully compatible with I2C's open-drain pull-up signalling, following NXP's recommended application circuit.

The converter works from 1.8V on the low side up to 10V on the high side, making it versatile for interfacing between 3.3V sensors and 5V microcontrollers, or any other voltage combination in that range. It also works with TTL serial, slow SPI (<2MHz), and other uni-directional or bi-directional digital interfaces.

Key Features

• I2C Compatible – BSS138 FET design works with I2C's pull-up signalling
• 4 Bi-Directional Channels – Level shift 4 signals simultaneously
• Wide Voltage Range – 1.8V to 10V, any combination of low and high side
• 10K Pull-Ups Included – Built-in on each channel
• Multi-Protocol – Works with I2C, TTL serial, slow SPI, and other digital interfaces

Specifications

• FET – BSS138 (×4)
• Pull-Up Resistors – 10K per channel
• Low Side Voltage – 1.8V to 3.3V (typical)
• High Side Voltage – Up to 10V
• Channels – 4 bi-directional
• Supported Protocols – I2C, TTL serial, slow SPI (<2MHz), GPIO

Ideal For

• Interfacing 3.3V sensors with 5V Arduino boards
• I2C bus level shifting
• Mixed-voltage prototyping
• Any project requiring safe voltage level conversion

Package Contents

• 1× Assembled and tested 4-channel level converter PCB
• 2× 6-pin headers (for breadboard use, soldering required)