Analog Devices Inc./Maxim Integrated MAX16050ETI+

MAX16050ETI+ Power Supply Monitor and Sequencer Product Summary

The MAX16050ETI+ from Analog Devices Inc./Maxim Integrated is a dedicated power supply monitor and sequencer tailored for complex electronic systems featuring multiple power rails. Housed in a compact 4mm x 4mm 28-TQFN package, the device is capable of monitoring up to five independent voltage sources and sequencing up to four supplies, offering advanced system reliability and startup/shutdown control. The MAX16050ETI+ brings precise control and monitoring to telecom, server, networking, and high-end workstation applications, where orderly power sequencing and robust fault detection are critical.

Highlights and Core Attributes of MAX16050ETI+

MAX16050ETI+ stands out with a rich feature set designed for demanding system power management:

Ability to monitor up to five voltages and sequence four.

Pin-selectable sequencing order, allowing up to 24 unique start-up sequences.

Reverse-sequencing for controlled shutdown scenarios.

Overvoltage monitoring with a dedicated output for system protection.

High threshold accuracy (±1.5%) for reliable voltage supervision.

Adjustable sequencing delay and reset timeouts via external capacitors.

Integrated charge pump to fully enhance external n-channel MOSFETs during sequencing.

Daisy-chain support to facilitate scalable multi-rail setups.

Internal 85mA pulldown circuits for rapid discharge of capacitive loads during shutdown.

MAX16050ETI+ Functional Analysis and Operational Principles

At its core, the MAX16050ETI+ manages the orderly progression of power supply rails during power-up, power-down, and system fault states. Upon system startup, the device maintains all sequenced rails in the off state until four critical conditions are satisfied: ABP input above undervoltage lockout, EN input above threshold, SHDN not asserted, and all monitored voltages below 250mV. Once conditions are met, the monitor begins the sequencing process according to the selected order, turning on each power supply as its predecessor reaches nominal voltage and incorporating a delay configurable via an external capacitor.

Reverse-sequencing is supported for controlled shutdowns: supplies are powered down one-by-one in the reverse of the startup sequence, each only turning off once the prior voltage falls below a defined threshold. This feature ensures proper discharge of rail capacitances and prevents latch-up or system corruption. The MAX16050ETI+ also provides a Power-On-Reset (RESET) signal, only releasing the system controller after all monitored rails achieve their specified voltages and hold them for the programmed timeout.

Power-Up and Power-Down Sequencing Strategies with MAX16050ETI+

The MAX16050ETI+ offers flexible sequencing logic via three state-capable sequence control inputs, enabling selection among 24 possible sequencing orders without changes to PCB layout—crucial for late-stage system modifications. Sequencing can be tailored for any combination of supply dependencies, supporting both performance tuning and system safety.

Reverse-sequencing is activated during power-down events when the SHDN pin is asserted. The device monitors each supply and ensures its voltage has declined below 250mV before proceeding to disable the next rail. This is particularly beneficial in systems where correct shutdown order is as important as startup, such as FPGA or processor-based platforms where improper sequencing can lead to logic faults or system instability.

Electrical Specifications of MAX16050ETI+

Engineered for robustness and precision, the MAX16050ETI+ operates from a 2.7V to 16V supply across a -40°C to +85°C temperature range. Key parameters include:

Absolute maximum VCC: -0.3V to +30V.

Input/output current capability: up to 20mA (some pins with higher ratings).

Precise undervoltage and overvoltage detection with open-drain fault notification.

Reset, discharge, and sequencing outputs managed to avoid erroneous transitions during brown-outs or power glitches.

Charge-pump output rated at VCC + 5V with a typical output current of 25μA, allowing direct MOSFET interface for switching power rails without additional drivers.

Common Use Cases for MAX16050ETI+

The versatility of the MAX16050ETI+ makes it a strong candidate for:

Server and storage equipment where orderly power sequencing prevents hardware damage during maintenance or faults.

Telecom infrastructure, benefiting from reliable power-up and reverse power-down sequencing for hot-swap high-availability designs.

Networking switches and routers requiring multi-rail power supply management for ASICs, FPGAs, or high-speed transceiver modules.

Workstations or embedded computing systems demanding robust sequencing and fault recovery to maximize system longevity and minimize service calls.

Technical Factors When Implementing MAX16050ETI+

Implementing the MAX16050ETI+ requires careful planning regarding resistor value selection for the monitored thresholds, ensuring both accuracy and manageable power loss. Input divider resistors for voltage sense should account for input leakage current to minimize threshold errors, with calculations balancing power and error as per the datasheet formulas.

External pullup resistors for open-drain outputs must be chosen based on voltage domain and expected sink currents. Special consideration is necessary when utilizing the CP_OUT charge-pump output to drive multiple MOSFET gates, as excessive load may impede reliable switching.

Unused channels should have their SET_ pins tied high and DISC_ pins grounded to maintain predictable behavior. Daisy-chaining multiple MAX16050ETI+ devices is supported and allows expansion to systems with more than four or five rails, using the REM and EN_HOLD features to coordinate inter-device handoff during both startup and shutdown.

MAX16050ETI+ Deployment in Multi-Rail Power Architectures

In multi-rail systems, the MAX16050ETI+ integrates as the central sequencing controller. In practical deployment—such as in an advanced telecom line card or high-reliability server motherboard—each power supply output (typically from a DC-DC converter) connects to the SET_ voltage monitor and OUT_ sequencer outputs. The device’s robust sequencing and power-down control help prevent data corruption and premature hardware wear, especially in systems supporting hot-swap or requiring field maintenance.

Its ability to discharge output capacitors quickly minimizes downtime and ensures the safe removal of circuit boards. The open-drain outputs and flexible delays make integration with a variety of FET types and supply configurations straightforward. In multi-board racks or large ASIC-based designs, several MAX16050ETI+ devices can be coordinated via their daisy-chain and FAULT logic to provide uniform, error-tolerant multi-rail sequencing.

Alternative and Substitute Options for MAX16050ETI+

When evaluating alternatives or second sources for the MAX16050ETI+, consider the following options within the Analog Devices/Maxim Integrated family:

MAX16051: Direct variant featuring six monitoring inputs and five sequencing outputs, suitable for larger rail counts but with fixed sequencing order.

Analog Devices ADP5024/ADP5050 families: For PMIC solutions with integrated and configurable sequencing, especially in lower-voltage, SOC-centric designs.

Texas Instruments TPS65023 or UCD90120: Multi-rail sequencers and monitors offering similar programmable sequencing and fault detection in competitive form factors.

Engineers should always match the specific sequencing count, threshold accuracy, startup/shutdown behavior, and package constraints before selecting an alternative.

Conclusion

The MAX16050ETI+ is a robust, feature-rich power supply monitor and sequencer that empowers engineers to design reliable, flexible, and safe multi-rail electronic systems. Its combination of configurable sequencing, reverse power-down, over/undervoltage monitoring, and expandability makes it an ideal choice for complex platforms. By understanding its operation, integration strategies, and relevant engineering considerations, product selection engineers and procurement specialists can confidently deploy the MAX16050ETI+ as a foundation for advanced power management in their critical designs.