Maxim Integrated DS1818R-5/T&R Microprocessor Reset Circuit

The Maxim Integrated DS1818R-5/T&R is a compact, reliable microprocessor (µP) supervisory circuit designed to monitor the power supplies in µP and digital systems. Providing a crucial function in system reliability, this reset circuit ensures that the µP boots up in a known state, free from any unpredictable conditions that could arise from power supply inconsistencies.

This device offers a precise monitoring feature for power supply voltages, with a factory-trimmed reset threshold of 4.63V, making it ideal for 5V power supply applications. The DS1818R-5/T&R actively monitors the V<sub>CC and, upon detecting an out-of-tolerance condition, asserts a reset signal to prevent system errors. The reset signal remains asserted for a minimum of 140ms after V<sub>CC has risen back to an acceptable level, providing enough time for the system to stabilize.

The DS1818R-5/T&R comes in a compact SOT-23 package, which is suitable for space-constrained applications. Its low power consumption makes it an excellent choice for portable and battery-operated devices. The device is offered in tape and reel (T&R) form, facilitating efficient assembly for high-volume production.

Key features of the DS1818R-5/T&R include:

• Precision temperature-compensated voltage reference and comparator
• 140ms (min) reset pulse width
• Factory-set reset threshold for 5V systems
• Low supply current of 4µA (typical)
• Immune to short V<sub>CC transients
• Available in SOT-23 packaging

The device is ideal for use in microprocessor systems, computers, controllers, and intelligent instruments, where it ensures that the system's microprocessor restarts in a known state during a power failure or brownout condition. By incorporating the DS1818R-5/T&R into your design, you can significantly enhance the reliability and robustness of your system.