MAX7321ATE+TG104

Overview

The MAX7321ATE+TG104 is an I2C port expander featuring eight open-drain I/O ports with selectable internal pullups and transition detection. It operates from a supply voltage of +1.71V to +5.5V and supports a 400kHz serial interface. Each port can function as a logic input or an open-drain output rated to sink 20mA, with overvoltage protection up to +6V independent of the supply voltage. The device utilizes AD0 and AD2 inputs to select one of 16 slave addresses, which also determines power-up logic states and enables internal 40kΩ pullups in groups of four. It includes a latching interrupt output (INT) for transient change detection and is specified over an operating temperature range of -40°C to +125°C.

Feature Summary

• Eight open-drain I/O ports capable of sinking 20mA each
• I/O ports are overvoltage protected to +6V independent of supply voltage
• Latching transition detection interrupt alerts on input state changes
• Selectable internal pullups and configurable power-up default logic states

Applications

• Cell Phones
• SAN/NAS
• Servers
• Notebooks
• Satellite Radio

Procurement Notes

Verify the component authenticity by checking the marking code 'ADC' on the TQFN-EP package against official Maxim Integrated documentation. Confirm the suffix '+TG104' corresponds to the lead-free/RoHS-compliant 16-pin Thin Quad Flatpack No-Lead (TQFN) package with an exposed pad. Ensure the ordering information matches the specific revision required for your design implementation.

Selection Notes

Select this part when eight bidirectional open-drain I/Os with hardware transition detection are required. It is suitable for applications needing level shifting between different logic voltages due to its +6V tolerant inputs. Consider the 16-addressable options if multiple expanders must share a single I2C bus. Verify that the 20mA sink current per port meets the load requirements for connected peripherals.

Part Context

The MAX7321 belongs to the MAX7319–MAX7329 family of pin-compatible port expanders. It serves as the I/O variant within this series, offering open-drain outputs unlike the input-only MAX7319 or push-pull output MAX7320. It shares the same 16-pin QSOP and TQFN packages and electrical characteristics as other family members, allowing for flexible design upgrades without PCB layout changes.

Replacement Considerations

Pin-compatible alternatives include the MAX7319 (input-only), MAX7320 (push-pull outputs), MAX7322 (4 inputs/4 outputs), and MAX7323 (4 I/O/4 outputs). For higher port counts, consider the 16-port MAX7324–MAX7327 series. Ensure the replacement maintains the required open-drain architecture and I2C compatibility.