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 40k pullups in groups of four ports. Eight ports are push-pull outputs and eight I/Os may be used as a logic input or an opendrain output. Ports are overvoltage protected to +6V. All I/O ports configured as inputs are continuously monitored for state changes (transition detection). 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). The MAX7325 is available in 24-pin QSOP and TQFN packages and is specified over the -40°C to +125°C automotive temperature range. 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. State changes are indicated by the 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 RST input clears the serial interface, terminating any I2C communication to or from the MAX7325.

The features of MAX7325 can be summarized as (1)400kHz I2C serial interface; (2)+1.71V to +5.5V operation; (3)8 push-pull outputs; (4)8 open-drain I/O Ports, rated to 20mA Sink Current; (5)I/O ports are overvoltage protected to +6V; (6)selectable I/O port power-up default logic states; (7)transient changes are latched, allowing detection between read operations; (8)INT output alerts change on inputs; (9)AD0 and AD2 inputs select from 16 slave addresses; (10)low 0.6A (typ)standby current; (11)-40°C to +125°C temperature range.

The absolute maximum ratings of MAX7325 are (1)supply voltage V+:-0.3V to +6V; (2)SCL, SDA, AD0, AD2, RST, INT, P0P7:-0.3V to +6V; (3)O8O15:-0.3V to (V+ + 0.3V); (4)O8O15 output current:±25mA; (5)P0P7 sink current:25mA; (6)SDA sink current: 10mA; (7)INT sink current:10mA; (8)total V+ current:50mA; (9)total GND current:100mA; (10)continuous power dissipation (TA = +70°C)24-Pin QSOP (derate 9.5mW/°C over +70°C):761.9mW/ 24-Pin TQFN (derate 20.8mW/°C over+70°C):1666.7mW; (11)operating temperature range:-40°C to +125°C; (12)junction temperature:+150°C; (13)storage temperature range:-65°C to +150°C; (14)lead temperature (soldering, 10s):+300°C.