SGM809-SXN3L/TR Microprocessor Supervisory Circuit in 3-Pin SOT-23

Product Overview

The SGM809-SXN3L/TR from SGMICRO is a high-precision, low-power microprocessor supervisory circuit designed to monitor system voltages and ensure reliable system reset during under-voltage conditions. It is functionally equivalent to ADM809SARTZ and ADM809SARTZ-REEL7 from Analog Devices, both of which are also single-channel microprocessor reset monitors with active-low reset output. While all these devices fulfill the core function of voltage supervision, SGM809-SXN3L/TR provides advantages in supply current, voltage accuracy, and pricing, making it an ideal solution for power-conscious and cost-sensitive designs.

Power Consumption Advantage

The SGM809-SXN3L/TR features ultra-low supply current consumption of only 0.5μA (typical), which is significantly lower than the ADM809SARTZ, which typically draws around 3μA. This over 80% reduction in power consumption is especially advantageous for battery-powered systems, IoT devices, and portable applications, where minimizing standby current is essential for extending operational life.

Voltage Threshold Accuracy

The SGM809-SXN3L/TR offers tight voltage threshold accuracy of ±1.4% (max), ensuring more reliable and predictable reset behavior compared to the ADM809SARTZ series, which typically provides ±2.5% threshold accuracy. This improved precision in voltage detection allows system designers to better protect against marginal brown-out conditions, thereby enhancing overall system robustness and stability.

Reset Timeout Period

The SGM809-SXN3L/TR offers a typical reset timeout of 240ms, which closely matches the ADM809SARTZ/ADM809SARTZ-REEL7 reset timeout period (~240ms typical). This ensures compatibility in systems that rely on a specific reset hold time for proper initialization. The pin-for-pin compatibility and matching timing parameters allow for direct replacement without firmware or hardware changes.

Packaging and Compatibility

The SGM809-SXN3L/TR comes in a space-saving SOT-23-3 package, which is mechanically and electrically compatible with the ADM809SARTZ and ADM809SARTZ-REEL7, both of which are also offered in the SOT-23-3 form factor. This enables seamless design migration or second-sourcing for users seeking better cost-performance balance or improved procurement reliability.

Operating Voltage Range

Both the SGM809-SXN3L/TR and ADM809SARTZ series support operation from 1.0V to 5.5V, making them well-suited for modern low-voltage digital logic systems (e.g., 1.8V, 2.5V, 3.3V, and 5V rails). The SGM809-SXN3L/TR maintains stable reset assertion across the entire operating range, ensuring robust protection for both legacy and next-generation power rails.

Reliability and Sourcing Benefits

SGMICRO offers short lead times, strong domestic supply chain support, and competitive pricing, particularly valuable in high-volume production environments. In contrast, Analog Devices’ ADM809SARTZ series may be subject to longer lead times or pricing volatility, especially during supply chain constraints. This makes the SGM809-SXN3L/TR a strategically advantageous alternative for OEMs and ODMs seeking supply resilience and BOM cost reduction.

Conclusion

While the ADM809SARTZ and ADM809SARTZ-REEL7 are well-established supervisor ICs, the SGM809-SXN3L/TR delivers superior power efficiency, tighter voltage accuracy, and equal timing compatibility, all in the same industry-standard package. Coupled with excellent availability and cost competitiveness, the SGM809-SXN3L/TR is an ideal drop-in alternative that enables designers to build more efficient, reliable, and cost-effective systems without compromising performance.