The MAX7327 is a 2-wire serial interface peripheral that 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 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 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). 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. Application Features ♦ 400kHz I2C Serial Interface ♦ +1.71V to +5.5V Operating Voltage ♦ 12 Push-Pull Output Ports, Rated at 20mA
The MAX7327 is a 2‑wire serial‑interfaced I2C port expander that provides twelve push‑pull output ports and four open‑drain I/O ports. It includes over‑voltage protection to +6 V, selectable internal pull‑ups, and an interrupt output that flags input state changes. The device operates over an automotive temperature range of –40 °C to +125 °C and is offered in 24‑pin QSOP and TQFN packages.
Key functional blocks include address selection via ADO and AD2 inputs, a power‑on reset circuit, standby mode for low power consumption, and configurable default logic states. The datasheet also contains absolute maximum ratings, detailed DC electrical characteristics, timing diagrams, pin descriptions, and package drawings.
| I2C Serial Interface Frequency | 400 kHz |
|---|---|
| Push‑Pull Output Current | 20 mA sink |
| Open‑Drain Over‑Voltage Protection | +6 V |
| Standby Current (typ) | 0.6 µA |
| Operating Temperature Range | -40 °C to +125 °C |
| Package Options | 24‑pin QSOP, TQFN (4 mm × 4 mm) |
The MAX7327 supports an I2C serial interface up to 400 kHz.
It provides twelve push‑pull output ports, each rated for a 20 mA sink current.
Yes, the open‑drain ports are over‑voltage protected to +6 V.
The device is offered in 24‑pin QSOP and TQFN (4 mm × 4 mm) packages.