MAX7324

The MAX7324 uses two address inputs with four-level logic to allow 16 I2C slave addresses. The slave address also enables or disables internal 40k pullups in groups of four ports. The interrupt is latched, allowing detection of transient changes. Any combination of inputs can be selected using the interrupt mask to assert the INT output. When the MAX7324 is subsequently accessed through the serial interface, any pending interrupt is cleared. The push-pull 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 MAX7324. The MAX7324 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 MAX7324 is available in 24-pin QSOP and TQFN packages, and is specified over the -40°C to +125°C automotive temperature range. The MAX7324 2-wire serial-interfaced peripheral features 16 I/O ports that are divided into eight push-pull outputs and eight inputs. Each input features selectable internal pullups, overvoltage protection to +6V, and transition detection with an interrupt output. All input ports are continuously monitored for state changes (transition detection).

The features of MAX7324 can be summarized as (1)400kHz, +6V-tolerant I2C serial interface; (2)+1.71V to +5.5V operating voltage; (3)eight push-pull outputs; (4)eight input ports with maskable, latching transition detection; (5)input ports are overvoltage protected to +6V; (6)transient changes are latched, allowing detection between read operations; (7)INT output alerts change on any selection of inputs; (8)AD0 and AD2 inputs select from 16 slave addresses; (9)low 0.6A standby current; (10)-40°C to +125°C temperature range.

The absolute maximum ratings of MAX7324 are (1)supply voltage V+:-0.3V to +6V; (2)SCL, SDA, AD0, AD2, RST, INT, I0I7:-0.3V to +6V; (3)O8O15: -0.3V to (V+ + 0.3V); (4)O8O15 Output Current:±25mA; (5)SDA sink current: 10mA; (6)INT sink current:10mA; (7)total V+ Current:50mA; (8)total GND Current:100mA; (9)continuous power dissipation 24-Pin QSOP (derate 9.5mW/°C over TA = +70°C):761.9mW; (10)24-Pin TQFN (derate 20.8mW/°C over TA = +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.