MAX9921AUB/V+

Sensor And Detector Interfaces Overview

The MAX9921AUB/V+ is a dual, 2-wire Hall-effect sensor interface with diagnostics. It supplies and monitors current for two sensors within a 6V to 18V operating range, withstands 60V transients at the BAT supply, and features open-drain logic outputs compatible up to 5.5V. The device includes input diagnostics for open circuits, battery shorts, and ground shorts, utilizing an 80µs blanking time after power-up. It operates over the -40°C to +125°C automotive temperature range in a 10-pin µMAX package.

Sensor And Detector Interfaces Feature Summary

• Provides supply current monitoring and interfaces to two 2-wire Hall-effect sensors
• Includes error output with diagnostics of Hall inputs and battery voltage
• Protects Hall sensors from overvoltage by isolating them from supply transients
• Features low-power shutdown controlled with OE and DIAG inputs

Sensor And Detector Interfaces Applications

• Door modules
• Window lifters
• Seat movers
• Electric sunroofs
• Powered lift gate controllers

Sensor And Detector Interfaces Procurement Notes

Verify the specific suffix /V+ indicates automotive qualification when sourcing this component. Confirm the package type matches the required 10-pin µMAX footprint for your PCB layout. Ensure the ordering information aligns with the manufacturer's current production status and lead times before finalizing procurement plans.

Sensor And Detector Interfaces Selection Notes

Select this part for applications requiring dual-channel Hall sensor interfacing with integrated fault protection. Verify that the system voltage remains within the 6V to 18V operating range. Consider the 10-pin µMAX package size constraints and ensure compatibility with the target microprocessor logic levels up to 5.5V.

Sensor And Detector Interfaces Part Context

The MAX9921AUB/V+ belongs to the MAX9921 series of sensor interface ICs designed for automotive environments. It is specifically qualified for the -40°C to +125°C temperature range, making it suitable for under-hood or chassis-mounted applications where robustness against electrical noise and transient voltages is critical.

Sensor And Detector Interfaces Replacement Considerations

Check for MAX9921AUB+T as a potential alternative if tape-and-reel packaging is preferred over tube. Verify functional equivalence regarding diagnostic modes and current thresholds before substitution.

Sensor And Detector Interfaces FAQ

How does the MAX9921 handle a short-to-ground fault on a Hall input?

The device shuts off current to the corresponding Hall sensor and asserts the ERR output low. It sources 50µA pullup current to aid troubleshooting, and a falling edge at the DIAG pin initiates a restart with a blanking cycle.

What is the purpose of the DIAG input?

Driving DIAG high enables diagnostic mode, allowing OUT1 and OUT2 to output diagnostic information about faults such as open circuits or shorts. Driving DIAG low returns the device to normal operation mode.

Can the MAX9921 operate with 3-wire Hall-effect switches?

Yes, it can be used with 3-wire Hall-effect switches configured as 2-wire devices by adding a resistor to ensure the current drawn crosses the MAX9921 current threshold when the magnetic threshold is exceeded.