MAX7321AEE+

Overview

The MAX7321AEE+ is an I2C serial port expander featuring eight open-drain I/O ports with selectable internal pullups and transition detection. It operates from a supply voltage ranging from +1.71V to +5.5V, supporting a maximum clock frequency of 400kHz. The device provides overvoltage protection on all pins up to +6V independent of the supply voltage. Each open-drain output can sink up to 20mA, suitable for driving LEDs or interfacing with various logic families. The component is specified for operation across an extended temperature range of -40°C to +125°C and is housed in a 16-pin QSOP package.

Feature Summary

• Eight configurable open-drain I/O ports capable of functioning as logic inputs or outputs
• Latching transition detection interrupt (INT) alerts the host to input state changes
• Overvoltage tolerant pins protected up to +6V regardless of supply voltage
• Dynamic slave address selection via AD0 and AD2 inputs allowing sixteen unique addresses

Applications

• Cell phones
• Servers
• Notebooks
• SAN/NAS systems
• Satellite radio

Procurement Notes

Verify the specific ordering suffix EE+ confirms the lead-free and RoHS-compliant QSOP-16 package variant. Confirm that the intended application environment remains within the specified -40°C to +125°C operating temperature range. Ensure the I2C bus capacitance does not exceed the maximum rated limit to maintain signal integrity at the supported clock speeds.

Selection Notes

Select this component when eight bidirectional open-drain ports are required alongside latching interrupt capabilities. It is appropriate for designs needing level shifting between different voltage domains due to the +6V tolerance. Consider alternative family members like the MAX7320 if push-pull outputs are preferred, or the MAX7319 if input-only masking is sufficient.

Part Context

This device belongs to the MAX7319–MAX7329 family of pin-compatible I/O expanders. While other variants in the series offer push-pull outputs or input-only configurations, the MAX7321 specifically provides open-drain I/Os with transition detection. It shares the same 16-pin footprint as related parts, facilitating design flexibility across product lines requiring different output drive characteristics.

Replacement Considerations

Direct pin-compatible substitutes within the same family include the MAX7321ATE+ (TQFN package). For functional equivalents with different output types, consider the MAX7319 (input-only) or MAX7320 (push-pull outputs), noting that register maps and electrical characteristics may differ.