Maxim Integrated MAX812REUS+T Microprocessor Reset Circuit

The MAX812REUS+T is a compact and efficient microprocessor (µP) supervisory circuit designed by Maxim Integrated to monitor power supplies in digital systems. It provides a crucial function in ensuring system reliability by asserting a reset signal whenever the V<sub>CC supply voltage drops below a preset threshold, maintaining it until the supply voltage stabilizes and an internal timer has expired. This component is particularly ideal for portable and space-constrained applications due to its small size and low power consumption.

Encased in a 4-pin SOT-143 package, the MAX812REUS+T offers a precise factory-set reset threshold voltage, which allows designers to tailor the reset function to the specific requirements of their microprocessor system. The device is capable of asserting a reset signal for a minimum of 140ms (typical) after V<sub>CC has risen above the reset threshold, ensuring that the system has ample time to stabilize before normal operation resumes.

One of the key features of the MAX812REUS+T is its ability to operate with a wide range of supply voltages, from 1.2V to 5.5V, making it versatile for use in various applications, from battery-powered devices to embedded systems. The low supply current draw of only 6µA (typical) at V<sub>CC = 3.3V ensures minimal impact on the overall power consumption of the system it is monitoring.

This supervisory circuit includes additional features such as a manual reset input, which allows for an external trigger to initiate the reset sequence. This feature is particularly useful for system testing and debugging. The MAX812REUS+T operates over a wide temperature range, from -40°C to +85°C, making it suitable for industrial applications where temperature extremes are common.

In summary, the Maxim Integrated MAX812REUS+T is a reliable and versatile microprocessor supervisory circuit that offers designers a compact solution for monitoring system power supplies, ensuring that digital systems operate with greater stability and reliability.