Analog Devices Inc./Maxim Integrated MAX6887HETE+

Overview

MAX6887HETE+ from Maxim Integrated is a hex-voltage supervisory IC with six factory-configured undervoltage/overvoltage detectors, 1% threshold accuracy, 180ms reset timeout, and integrated watchdog timer (102.4s initial / 1.6s normal). It operates from -40°C to +85°C in multivoltage server power systems where simultaneous monitoring of 3.3V, 1.8V, and three adjustable rails is required.

For engineers reviewing the MAX6887HETE+ datasheet, MAX6887HETE+ pinout, MAX6887HETE+ application, or MAX6887HETE+ equivalent, key selection criteria include confirmed 3.3V/1.8V fixed thresholds (IN1=3.06V UV / 3.54V OV; IN2=1.67V UV / 1.93V OV), six-input supervision architecture, open-drain active-low outputs (RESET/OV/WDO), and 16-pin 5mm×5mm thin QFN-EP package compatibility with high-density PCB layouts.

Technical Context

The MAX6887HETE+ implements independent voltage-detection comparators for each of its six inputs, with factory-trimmed thresholds referenced to a 0.6V internal reference and ±1% accuracy over temperature. Its virtual diode-OR power architecture selects the highest valid input (IN1–IN4) ≥2.7V to supply internal circuitry, eliminating need for external VCC biasing in most configurations.

It integrates a dual-mode watchdog timer with programmable initial timeout (102.4s) for processor initialization and shorter normal timeout (1.6s) for runtime supervision. All three outputs-RESET, OV, and WDO-are active-low open-drain with 0.4V max VOL at 4mA sink current and require external pullups; RESET remains asserted for 200ms after fault clearance, while OV deasserts after only 25µs.

Key Specifications

Pinout & Package

MAX6887HETE+ uses a 16-pin 5mm × 5mm thin QFN-EP package with exposed pad (EP) internally connected to GND. The package supports thermal dissipation up to 1667mW at +70°C and is RoHS-compliant (lead-free).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power-supply supervisory applications.

Compared with MAX6888HETE+, the MAX6887HETE+ provides two additional voltage-monitoring channels and greater design flexibility for evolving power architectures, while TPS3808G33DBVR offers lower unit cost at the expense of system-level integration, reliability, and feature completeness.

Availability

MAX6887HETE+ is available at Aetrix Electronics and suitable for server/workstation power sequencing, telecom line card monitoring, and industrial storage controller applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for MAX6887HETE+ 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 demanding industrial, communications, and computing applications.

The MAX6887/MAX6888 family was engineered specifically for multivoltage digital systems requiring consolidated supervision of six or four independent power rails with integrated watchdog safety features.

FAQ

What are the exact undervoltage and overvoltage thresholds for MAX6887HETE+?

The MAX6887HETE+ has factory-set thresholds: IN1 = 3.06V UV / 3.54V OV, IN2 = 1.67V UV / 1.93V OV, and IN3–IN6 = 0.557V UV / 0.643V OV. These values are specified in Table 1 of the datasheet with ±1% accuracy over -40°C to +85°C. The MAX6887HETE+ does not support user-adjustable thresholds on IN1 or IN2-only IN3–IN6 are configured as "Adj" inputs.

Can MAX6887HETE+ be powered solely from IN1 and IN2, or is VCC required?

MAX6887HETE+ can be powered exclusively from IN1 or IN2-no external VCC connection is required. Its virtual diode-OR architecture automatically selects the highest valid voltage among IN1–IN4 (≥2.7V) to supply internal circuitry. Since IN1 = 3.06V and IN2 = 1.67V, only IN1 meets the 2.7V minimum; thus, IN1 must be present and stable for operation. VCC is an internal node, not an input.

How does the MARGIN input affect RESET, OV, and WDO outputs in MAX6887HETE+?

When MARGIN is pulled low, MAX6887HETE+ freezes the states of RESET, OV, and WDO regardless of subsequent voltage faults or watchdog timeouts. This allows system-level stress testing under out-of-spec conditions without triggering spurious resets. MARGIN overrides MR if both are asserted simultaneously, and it is internally pulled up to BP via a 10µA current source when unused.

What is the recommended bypassing scheme for MAX6887HETE+?

Each voltage-detector input (IN1–IN6) requires a 0.1µF ceramic capacitor to GND placed as close as possible to the pin. VCC and BP each require a 1µF ceramic capacitor to GND, also placed adjacent to their respective pins. The exposed pad (EP) must be soldered to a solid GND plane. These capacitors ensure noise immunity and stable internal regulation-omitting them risks false trips or erratic watchdog behavior in MAX6887HETE+.

Is MAX6887HETE+ pin-compatible with other variants in the MAX6887 family?

Yes, all MAX6887 variants-including MAX6887HETE+-share identical 16-pin thin QFN-EP packaging and pinout. Differences exist only in factory-programmed thresholds (e.g., MAX6887AETE+ monitors 5V/3.3V/2.5V/1.8V rails), but mechanical and electrical interface compatibility is maintained across the family. This allows drop-in replacement during design iteration or qualification without PCB changes.