Maxim Integrated MAX6809M-UR Microprocessor Reset Circuit

The MAX6809M-UR from Maxim Integrated is a highly reliable microprocessor (µP) supervisory circuit designed to monitor power supplies in µP and digital systems. It provides a significant level of system reliability through its ability to reset a system during a brownout or power failure condition, ensuring that the µP restarts in a known state.

This compact device is available in a 3-pin SOT23 package, making it an ideal fit for space-constrained applications. The MAX6809M-UR operates over a wide voltage range and features a low supply current, making it suitable for use in portable equipment and other power-sensitive designs.

The supervisory circuit monitors the system voltage and maintains a reset output until the system voltage stabilizes above the factory-set reset threshold. The reset threshold for the MAX6809M-UR variant is precisely set at the factory and maintains ±2.5% reset threshold accuracy over the full temperature range. The reset output remains asserted for a minimum reset timeout period after the system voltage exceeds the reset threshold, ensuring proper system reset. The minimum reset timeout period for this device is typically 140ms.

Key features of the MAX6809M-UR include:

• Factory-set reset threshold voltage for assured system reliability
• Low 5.5µA supply current, ideal for battery-powered applications
• Guaranteed reset valid to VCC = 1V for low-voltage operation
• Immune to short VCC transients
• Wide operating temperature range from -40°C to +85°C

Applications that can benefit from the MAX6809M-UR include:

• Computers and controllers
• Embedded systems
• Battery-powered equipment
• Industrial equipment
• Portable consumer electronics

By integrating the MAX6809M-UR into your system, you can ensure robust and reliable operation even under adverse power conditions, thereby protecting your system from unexpected failures and data corruption.