The MAX7328/MAX7329 are 2-wire serial-interfaced peripherals with eight I/O ports. Any port can be used as a logic input or an open-drain output. All input ports are continuously monitored for state changes (transition detection).
The MAX7328 and MAX7329 are general‑purpose I2C port expanders that provide eight open‑drain I/O pins. Each pin can operate as a logic input or an output, and the devices include an open‑drain interrupt output (INT) that signals any input change.
Key features include selectable 7‑bit slave addresses (0x20‑0x27 for MAX7328, 0x38‑0x3F for MAX7329), a 2.5 V‑5.5 V supply range, low standby current, and the ability to sink up to 20 mA per pin (100 mA total). The parts are offered in 16‑Pin Wide‑SO, 20‑Pin SSOP and 20‑Pin TSSOP packages and operate over an automotive temperature range of –40 °C to +125 °C.
| Operating Supply Voltage (V+) | 2.5 V to 5.5 V |
|---|---|
| Standby Current | 10 pA (max) |
| Serial Clock Frequency | 100 kHz |
| Interrupt Output Voltage Rating | 5.5 V tolerant |
| Operating Temperature Range | -40 °C to +125 °C |
The MAX7328 uses a slave ID range of 0x20 to 0x27.
The MAX7329 uses a slave ID range of 0x38 to 0x3F.
Up to eight MAX7328 devices and eight MAX7329 devices can be controlled independently, for a total of sixteen devices.
Each port can sink up to 20 mA, with a total sink capability of up to 100 mA.