Analog Devices Inc./Maxim Integrated MAX6727KAVHD3+

Overview

MAX6727KAVHD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It provides two open-drain active-low reset outputs (RST, RST2), manual reset input (MR), watchdog timer (35s startup / 1.12s normal timeout), and operates from -40°C to +85°C. It ensures reliable system boot and brownout recovery in multivoltage embedded power rails.

For engineers reviewing the MAX6727KAVHD3+ datasheet, MAX6727KAVHD3+ pinout, MAX6727KAVHD3+ application, or MAX6727KAVHD3+ equivalent, key selection criteria include dual independent reset outputs, factory-trimmed dual-supply thresholds with third-voltage adjustability, guaranteed reset validity down to VCC = 0.8V, low 14µA supply current, and immunity to sub-20µs VCC transients - critical for battery-powered and telecom infrastructure designs.

Technical Context

The MAX6727KAVHD3+ implements a dual-comparator architecture with independent VCC1 and VCC2 monitoring paths feeding a shared reset timeout timer, plus a dedicated RSTIN comparator referenced to a 626.5mV internal bandgap. Its dual open-drain RST outputs are driven by identical logic but sourced from separate output drivers - one referenced to VCC1 (RST), the other to VCC2 (RST2) - enabling independent reset signaling for I/O and core domains.

It integrates a dual-mode watchdog with a 35s minimum initial timeout after any reset event (power-up, MR, or watchdog timeout), followed by a 1.12s minimum normal timeout triggered by the first WDI edge. The MR input features a 50kΩ internal pullup to VCC1 and 100ns glitch rejection, while RSTIN accepts external resistor-divider networks for precise third-voltage monitoring down to 0.62V.

Key Specifications

Pinout & Package

MAX6727KAVHD3+ is housed in an 8-pin SOT23-8 package (2.0mm × 2.1mm × 1.25mm), optimized for high-density PCB layouts in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-voltage supervisory applications.

Compared with MAX6727KAVHD3+, MAX6725KAHVD3+ adds power-fail functionality at the cost of increased design complexity, while TPS3808G33DBVR reduces feature set and flexibility to meet minimal supervision needs - making MAX6727KAVHD3+ optimal for balanced triple-rail reliability without PFI overhead.

Availability

MAX6727KAVHD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, portable medical devices, and networking switch fabric cards requiring stable component supply and long-term lifecycle support.

Supply support for MAX6727KAVHD3+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and connectivity applications, with leadership in supervisory, PMIC, and interface solutions.

The MAX6715–MAX6729 family delivers ultra-low-voltage, multi-rail supervision for space-constrained embedded systems - engineered to replace discrete reset circuits with guaranteed timing, low power, and robust noise immunity.

FAQ

What are the factory-trimmed reset thresholds for MAX6727KAVHD3+?

The MAX6727KAVHD3+ has factory-trimmed VCC1 and VCC2 reset thresholds of 4.625V and 3.075V respectively, with ±1.5% tolerance over temperature. These values are encoded in the "KV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and are verified across the full -40°C to +85°C operating range. The RSTIN input uses a fixed 626.5mV internal reference for third-voltage monitoring.

Does MAX6727KAVHD3+ support both push-pull and open-drain reset outputs?

No, MAX6727KAVHD3+ provides two open-drain active-low reset outputs: RST (referenced to VCC1) and RST2 (referenced to VCC2). It does not include push-pull outputs. External pullup resistors are required on both RST and RST2 lines; recommended values are 10kΩ for standard CMOS loads or 4.7kΩ when interfacing with bidirectional µP reset pins.

How does the watchdog timer operate in MAX6727KAVHD3+?

The MAX6727KAVHD3+ watchdog timer operates in dual mode: a 35s minimum initial timeout after any reset event (power-up, MR, or prior watchdog timeout), followed by a 1.12s minimum normal timeout triggered by the first valid WDI edge. The timer resets on rising or falling edges of WDI; if no transition occurs within the active timeout period, RST and RST2 assert for 210ms.

Can MAX6727KAVHD3+ monitor a negative supply voltage?

Yes, MAX6727KAVHD3+ can monitor negative supplies using the RSTIN input with an appropriate resistor-divider network that translates the negative voltage into a positive voltage relative to GND, staying within the 0V to VCC1 common-mode range. The internal 626.5mV reference remains fixed, so the divider must scale the negative rail such that trip occurs at the desired negative threshold.

What is the minimum supply voltage at which MAX6727KAVHD3+ guarantees valid reset output logic?

MAX6727KAVHD3+ guarantees correct reset output logic state as long as either VCC1 or VCC2 remains greater than 0.8V. Below this level, reset behavior is not specified. For operation down to 0V, a 100kΩ pull-down resistor on RST is recommended - though this applies only to push-pull variants; MAX6727KAVHD3+'s open-drain outputs require pullups, not pull-downs.