MAX809EUR - Microprocessor Reset Circuit

The MAX809EUR from Maxim Integrated is a compact, highly efficient microprocessor (μP) supervisory circuit designed to monitor power supplies in digital systems. It provides excellent circuit reliability and low cost by eliminating external components and adjustments when used in systems with +3V to +5V powered μPs.

This supervisory circuit asserts a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. The reset output is available in both active-low (MAX809) and active-high (MAX810) configurations, ensuring the MAX809EUR can interface with a wide range of microprocessors and microcontrollers, which require different reset signal polarities.

The MAX809EUR features an integrated voltage monitor that guards against power supply fluctuations, brownouts, and other conditions that could lead to system errors. This makes it an ideal choice for portable devices, computers, controllers, and intelligent instruments where precise power monitoring is crucial for data integrity and reliable operation.

This device is available in a small SOT-23 package, making it suitable for space-constrained applications. Its low power consumption and wide operating temperature range of -40°C to +105°C ensure that it performs reliably in a variety of harsh environments.

Key features of the MAX809EUR include:

• Precision monitoring of +3V, +3.3V, and +5V power-supply voltages
• Fully specified over temperature
• No external components needed
• 140ms (min) power-on reset pulse width
• Guaranteed reset valid to VCC = +1V
• Low power consumption
• Compact SOT-23 packaging

The MAX809EUR is an essential component for any system where reliable operation is paramount, ensuring that all processes are reset and initiated correctly upon power-up or during unwanted power dips. Its ease of integration and robust feature set make it a go-to solution for designers looking to enhance system stability without increasing complexity.