Maxim Integrated MAX809LEXR+T Microprocessor Reset Circuit

The MAX809LEXR+T is a compact, highly efficient microprocessor (µP) supervisory circuit designed to monitor power supplies in digital systems. Manufactured by Maxim Integrated, a leader in analog and mixed-signal products, this device is engineered to ensure that microprocessors and other digital systems operate reliably by providing a reset signal whenever the supply voltage drops below a predetermined threshold.

Featuring a low power consumption and a small footprint, the MAX809LEXR+T is an ideal choice for portable and space-constrained applications. It comes in a 3-pin SOT-23 package, which is favored for its minimal real estate on printed circuit boards (PCBs). With its precision factory-trimmed reset thresholds, the device caters to the needs of various systems without the requirement for external components, simplifying design and reducing overall system cost.

The MAX809LEXR+T offers several key features that make it a robust solution for system stability:

• Reset Output: The reset output remains asserted for a minimum of 140ms after V<sub>CC has risen above the reset threshold level, ensuring adequate time for the system to stabilize.
• Low Power Consumption: With a typical supply current of only 20µA, this device is highly energy-efficient, making it suitable for battery-operated applications.
• High Threshold Accuracy: The reset threshold accuracy is ±2.5% at room temperature and ±3% over the full temperature range of -40°C to +85°C, providing reliable operation under varying conditions.
• Immune to Short V<sub>CC Transients: The circuit is designed to ignore fast transients on the V<sub>CC line, preventing unnecessary resets due to noise or brief voltage dips.

The MAX809LEXR+T is versatile and can be used in a wide array of applications including computers, controllers, intelligent instruments, portable/battery-powered equipment, and other microprocessor-based systems that require precise monitoring of the power supply voltage.

By integrating the MAX809LEXR+T into your design, you can enhance the reliability and performance of your digital systems, ensuring that they operate without interruption or data loss due to unexpected power supply fluctuations.