The MAX7327, a 2-wire serial-interfaced peripheral, features 12 push-pull outputs and four configurable open-drain I/O ports with selectable internal pullups and transition detection. Ports are overvoltage protected to +6V, independent of supply voltage.
The four I/O ports configured as inputs are continuously monitored for state changes (transition detection). State changes are indicated by the open-drain, +6V-tolerant active-low INT output. The interrupt is latched, detecting transient changes. When the MAX7327 is subsequently accessed through the serial interface, any pending interrupt is cleared. The 12 push-pull and the four open-drain outputs are rated to sink 20mA, and are capable of driving LEDs. The active-low RST input clears the serial interface, terminating any I²C communication to or from the MAX7327.
The MAX7327 uses two address inputs with four-level logic to allow 16 I²C slave addresses. The slave address also determines the power-up logic state for the I/O ports, and enables or disables internal 40kΩ pullups in groups of two ports.
The MAX7327 is one device in a family of pin-compatible port expanders with a choice of input ports, open-drain I/O ports, and push-pull output ports (see Table 1 in the full data sheet).
The MAX7327 is available in the 24-pin QSOP and TQFN packages, and is specified over the -40°C to +125°C automotive temperature range.