Multi-Voltage Supervisor for Three-Rail Sequencing
The Analog Devices LTC1728ES5-5#TRMPBF is a three-channel multi-voltage supervisor that monitors up to three supply rails simultaneously, asserting a common active-low reset when any monitored voltage falls below its threshold. It is designed for systems requiring reliable power-up sequencing and brown-out detection across multiple voltage domains, such as mixed-signal boards with 5V, 3.3V, and a core logic rail. Housed in a TSOT-23-5 package, the device occupies minimal board area and is specified over the industrial temperature range of -40°C to 85°C, making it suitable for telecom infrastructure, industrial controllers, and embedded computing platforms.
Output Type and Interface Considerations
The open-drain, active-low output requires an external pull-up resistor to the monitored rail or to the system's logic supply. This topology allows the reset signal to be wire-ORed with other reset sources, and the output remains valid even if the monitored supply drops to zero, because the pull-up is referenced to a separate rail. The 140ms minimum reset timeout ensures that the system clock and PLLs have time to settle before the processor is released from reset.
Lifecycle and Compliance
It is ROHS3 compliant, meeting the latest restriction-of-hazardous-substances directive. For production BOMs, this part presents no imminent obsolescence risk, though as with any active semiconductor, periodic PCN monitoring is recommended.