The SGM809-ZXN3/TR is a voltage supervisory circuit, often referred to as a reset IC, manufactured by SG Micro Corp. Its primary function is to monitor the supply voltage of microprocessors (MCUs), microcontrollers, digital signal processors (DSPs), and other digital systems. The device is designed to detect undervoltage conditions, and when the supply voltage falls below a predefined threshold, it asserts a reset signal to prevent the system from operating incorrectly or corrupting data. This makes it an essential component for ensuring reliable system operation, particularly in environments with fluctuating power supplies or during power-up and power-down sequences.

Applications

• Microprocessor/Microcontroller Reset: Providing a reliable reset signal for MCUs and other digital systems during power-up, power-down, and brown-out situations.
• Power-On Reset (POR): Generating a reset signal upon initial power application to ensure proper system initialization.
• Brown-Out Protection: Preventing system errors and data loss due to low voltage conditions.
• Voltage Monitoring: Continuously monitoring the power supply voltage to detect deviations from the expected range.
• Embedded Systems: Employed in a wide array of embedded systems requiring robust voltage monitoring and reset capabilities.

Features

• Precision Voltage Monitoring: Accurately monitors the supply voltage to ensure reliable detection of undervoltage conditions.
• Reset Output: Generates a reset signal when the monitored voltage falls below the specified threshold. The reset output is typically active-low.
• Fixed Threshold Voltage: The threshold voltage is pre-set, providing a specific undervoltage detection point.
• Low Quiescent Current: Minimizes power consumption, making it suitable for battery-powered and energy-sensitive applications.
• Small Package: Available in a compact XN3 package, conserving valuable board space.
• Active-Low Reset Output: Outputs a logic low signal when a reset condition is detected.

Benefits

• Enhanced System Reliability: Prevents system malfunction and data corruption resulting from low voltage conditions.
• Simplified Design: Integrates voltage monitoring and reset generation into a single device, reducing component count and simplifying circuit design.
• Reduced Power Consumption: Low quiescent current extends the operating life of battery-powered devices.
• Space Saving: Compact package enables high-density circuit layouts, suitable for applications with limited space.
• Automatic Reset: Automatically resets the system during power-up and brown-out scenarios, eliminating the need for manual intervention.

Additional Details

The SGM809-ZXN3/TR incorporates a precision voltage reference, a comparator, and a reset output driver to achieve its voltage monitoring and reset generation functionality. When the monitored voltage remains above the specified threshold, the reset output is de-asserted (high). Upon detecting an undervoltage condition, the reset output is asserted (low). The reset output typically remains asserted for a predetermined reset timeout period after the voltage recovers above the threshold, ensuring that the system has sufficient time to properly initialize. The specific threshold voltage and reset timeout period for the SGM809-ZXN3/TR variant can be found in the manufacturer's datasheet. The device is supplied in tape and reel packaging for automated assembly. Proper decoupling capacitors should be employed to ensure stable operation and mitigate noise. Detailed electrical characteristics, timing diagrams, and application notes can be found in the product datasheet.