The MAX7301 is a 4-wire serial interface I/O expander chip from MAXIM Corporation. It supports 20/28 I/O ports and can be configured as open drain output, Schmitt input, Schmitt input with internal pull-up, and supports logic transition detection. The maximum operating current is 11µA, and the operating temperature range is -40℃~+125℃
The MAX7301 is a compact, serial‑interfaced I/O expander that provides up to 28 GPIO ports. Each port can be individually configured as a push‑pull output (10 mA sink, 4.5 mA source) or a Schmitt‑trigger input with optional internal pull‑up. Seven ports support transition detection, generating an interrupt on port P31 when a change is detected.
The device operates from a 2.5 V to 5.5 V supply and functions over an industrial temperature range of –40 °C to +125 °C. It uses a standard 4‑wire SPI‑compatible interface (SCLK, CS, DIN, DOUT) and supports daisy‑chaining of multiple devices. Detailed electrical characteristics, timing parameters, pin assignments, and register maps are provided for system integration.
| Number of I/O Ports | 20 or 28 |
|---|---|
| Output Drive Capability | Sink 10 mA, Source 4.5 mA |
| Shutdown Current | 11 pA (max) |
| Operating Temperature Range | -40 °C to +125 °C |
Depending on the package, the MAX7301 provides either 20 or 28 configurable I/O ports.
Each push‑pull output can sink up to 10 mA and source up to 4.5 mA.
When a monitored port changes state, the device asserts an active‑high interrupt on port P31 (INT).