IC Port Expander with 8 Push-Pull and 8 Open-Drain I/Os

The MAX7325 2-wire serial-interfaced peripheral features 16 I/O ports. Ports are divided into eight push-pull outputs and eight I/Os with selectable internal pullups and transition detection. Eight ports are push-pull outputs and eight I/Os may be used as a logic input or an open-drain output. Ports are overvoltage protected to +6V.

All I/O ports configured as inputs are continuously monitored for state changes (transition detection). State changes are indicated by the active-low INT output. The interrupt is latched, allowing detection of transient changes. When the MAX7325 is subsequently accessed through the serial interface, any pending interrupt is cleared. The 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 MAX7325.

The MAX7325 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 four ports.

The MAX7325 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 of the full data sheet).

The MAX7325 is available in 24-pin QSOP and TQFN packages and is specified over the -40°C to +125°C automotive temperature range.

Applications

* Automotive * Cell Phones * Notebooks * SAN/NAS * Satellite Radio * Servers

* 400kHz I2C Serial Interface

* +1.71V to +5.5V Operating Voltage

* 8 Push-Pull Output Ports

* 8 Open-Drain I/O Ports, Rated at 20mA Sink Current

* I/O Ports are Overvoltage Protected to +6V

* Selectable I/O Port Power-Up Default Logic States

* Transient Changes are Latched, Allowing Detection Between Read Operations

* Active-Low INT Output Alerts Changes on Inputs

* AD0 and AD2 Inputs Select from 16 Slave Addresses

* Low 0.6µA (typ) Standby Current

* -40°C to +125°C Temperature Range