Maxim Integrated MXD1817UR29 Microprocessor Reset Circuit

The MXD1817UR29 from Maxim Integrated is a highly efficient microprocessor (µP) supervisory circuit designed to monitor power supplies in digital systems. It provides a crucial function in ensuring system reliability by asserting a reset signal whenever the VCC supply voltage drops below a preset threshold, maintaining it until the supply voltage stabilizes above the threshold. This feature helps to prevent erratic operation during power-up, power-down, and brown-out conditions.

This particular model, the MXD1817UR29, has a factory-set reset threshold voltage of 2.93V, which is suitable for 3.3V-powered systems. The reset output is active-low and comes in a push-pull configuration, which means it does not require an external pull-up resistor. The device is characterized for operation over the full industrial temperature range of -40°C to +85°C, making it versatile for various industrial applications.

One of the key benefits of the MXD1817UR29 is its low power consumption, drawing a quiescent current of only 1.6µA (typical), which is ideal for power-sensitive applications. The component is packaged in a compact, 3-pin SOT-23, which is advantageous for space-constrained designs.

Additional features of the MXD1817UR29 include:

• A minimum power-on reset pulse duration of 140ms, which ensures a reliable reset of the µP during power-up.
• Immunity to short VCC transients, avoiding unnecessary resets due to brief glitches on the power supply line.
• Manual reset capability, allowing the user to initiate a system reset by pulling the reset line low.

The MXD1817UR29 is ideal for use in a broad range of applications, including:

• Portable/battery-powered equipment
• Embedded controllers
• Intelligent instruments
• Automotive systems
• Medical devices

In conclusion, the MXD1817UR29 microprocessor reset circuit from Maxim Integrated is a reliable and power-efficient solution for managing system resets in electronic devices. Its low power consumption, compact size, and robust feature set make it an excellent choice for designers looking to enhance system reliability and performance.