8-bit I2C GPIO expander with POR and wide temp range
The Maxim Integrated MAX7310ATE+ is an 8-bit I/O expander that connects to a host controller via the I2C or SMBus interface, running at up to 400 kHz. It provides eight configurable I/O pins that can be set as open-drain or push-pull outputs, with a per-pin output current rating of 18 mA source and 30 mA sink. The part includes a power-on reset (POR) feature that initializes the I/O states to a known condition on power-up. The supply voltage range of 2.3 V to 5.5 V allows operation on both 3.3 V and 5 V logic rails, and the -40°C to +125°C operating temperature range makes it suitable for automotive under-hood and industrial environments where temperature extremes are common. The device is supplied in a 16-TQFN (4x4 mm) package with an exposed pad for thermal management.
Supply voltage and temperature — what they mean for your design
The 2.3 V to 5.5 V supply range is wide enough to cover the two most common digital logic rails: 3.3 V and 5 V. This eliminates the need for a separate level shifter when the I2C bus runs at a different voltage than the expander's supply, as long as the bus voltage is within the same range. The -40°C to +125°C temperature grade is a full automotive/industrial rating, not a commercial 0°C to 70°C grade. That means the part is characterized and guaranteed over the entire range, so you can use it in engine-bay electronics, outdoor telecom cabinets, or factory-floor sensors without derating concerns.
Output drive and I/O configuration
Each of the eight I/O pins can be individually programmed as open-drain or push-pull. The 18 mA source and 30 mA sink capability is enough to directly drive small LEDs, optocoupler inputs, or low-power relays without external buffer transistors. For higher-current loads, you can parallel multiple outputs, but remember that the total package dissipation limits the sum. The open-drain option is useful for wired-OR connections or when driving loads that require a pull-up to a different voltage rail.
Lifecycle and sourcing
It is ROHS3 compliant, so it meets the latest European and global environmental requirements. There is no official second-source or pin-compatible alternate listed in the Maxim portfolio, so this is a single-source component for the footprint.