Analog Devices Inc./Maxim Integrated MAX6878ETG+

Overview

MAX6878ETG+ from Maxim Integrated is a triple-voltage power-supply tracker/sequencer/supervisor that monitors IN1, IN2, and IN3 (0.5V–5.5V), controls three external n-channel FETs via GATE1–GATE3, enforces ±125mV tracking accuracy during ramp-up/down, supports capacitor-adjustable slew rate (via SLEW pin), and delivers a programmable power-good timeout (via TIMEOUT pin) for system reset coordination in multivoltage server and telecom power rails.

For engineers reviewing the MAX6878ETG+ datasheet, MAX6878ETG+ pinout, MAX6878ETG+ application, or MAX6878ETG+ equivalent, this device is selected when precise voltage tracking across three supplies-such as 3.3V, 1.8V, and 0.7V-is required with fault detection, autoretry/latch-off mode selection, and internal charge-pump-driven gate drive for low R_DS(on) enhancement of external FETs.

Technical Context

The MAX6878ETG+ implements independent comparator-based tracking control per channel, comparing each OUT_ against a shared internal ramp generator while simultaneously monitoring differential deviation (±125mV tracking window, ±250mV fault threshold). Its TRK/SEQ pin selects between simultaneous tracking (low) or sequential turn-on (high/unconnected), with DELAY and SLEW pins enabling capacitor-programmed startup delay and slew-rate control respectively.

It integrates three independent charge pumps (one per GATE output) to boost GATE voltage to VINx + 5V, ensuring full enhancement of low-threshold n-channel FETs even at sub-1V input rails. The FAULT output asserts low on tracking violation or supply collapse, activating internal 100Ω pulldowns on all OUT_ pins to rapidly discharge capacitive loads.

Key Specifications

Pinout & Package

MAX6878ETG+ uses a 4mm × 4mm 24-pin thin QFN package with exposed paddle (EP) connected to GND. Pin count and layout match the MAX6877/MAX6879 family but differ functionally at PIN 10 (TIMEOUT present), PIN 14 (PG/RST present), and absence of SET3 (PIN 3), confirming MAX6878-specific dual-tracking + PG/RST capability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power-supply tracking and sequencing applications.

Compared with MAX6877ETG+ and MAX6879ETG+, the MAX6878ETG+ uniquely balances dual-input tracking capability (SET1/SET2) with integrated PG/RST and TIMEOUT programmability-making it optimal for systems needing reliable reset coordination without third-rail complexity.

Availability

MAX6878ETG+ is available at Aetrix Electronics and suitable for server power sequencing, telecom line card supervision, network switch ASIC power management, and industrial PLC multirail control requiring stable component supply and long-term lifecycle support.

Supply support for MAX6878ETG+ 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 management, sensing, and interface applications in industrial, communications, and computing markets.

The MAX6877/MAX6878/MAX6879 product line targets multivoltage digital systems requiring deterministic power-up/down behavior-specifically engineered for servers, storage, and telecom infrastructure where rail coordination prevents functional failure.

FAQ

What is the maximum number of voltage rails the MAX6878ETG+ can supervise?

The MAX6878ETG+ supervises up to two primary input rails (IN1 and IN2) with dedicated SET1 and SET2 pins for independent undervoltage threshold configuration. While IN3 is physically present on the 24-pin QFN package, the MAX6878ETG+ does not include a SET3 pin or associated internal circuitry-confirming its design as a dual-input tracker/sequencer. This distinguishes it from the MAX6879ETG+, which supports full triple-input operation.

Does the MAX6878ETG+ support both tracking and sequencing modes?

Yes, the MAX6878ETG+ supports both modes via the TRK/SEQ pin: driving it low enables simultaneous voltage tracking across all enabled outputs, while connecting it to ABP (or leaving it open) configures the device for sequential power-up (OUT1 → OUT2 → OUT3) with capacitor-adjustable inter-step delay via the DELAY pin. Power-down always follows tracking behavior regardless of mode selection.

How does the MAX6878ETG+ handle fault conditions during power-up?

During power-up, the MAX6878ETG+ continuously compares each OUT_ voltage against an internal reference ramp. If any OUT_ deviates by more than ±250mV from the ramp, the FAULT pin asserts low, all GATE outputs are disabled, and internal 100Ω pulldowns on OUT1–OUT3 rapidly discharge connected capacitance. This action terminates the power-up sequence and prevents downstream damage from uncontrolled rail collapse.

What is the role of the ABP pin on the MAX6878ETG+?

The ABP pin on the MAX6878ETG+ serves as the internal analog supply bypass node, powered by the highest voltage among IN1, IN2, IN3, or VCC. It must be decoupled to GND with a 1µF ceramic capacitor placed adjacent to the package. ABP maintains stable internal bias during fast power transitions and enables tracking of IN_ voltages below 2.7V when VCC is used-but it must never be used to power external circuitry.

Can the MAX6878ETG+ drive n-channel MOSFETs with input rails below 1V?

Yes, the MAX6878ETG+ can drive n-channel MOSFETs with input rails as low as 0.5V thanks to its integrated charge pumps. Each GATE output (GATE1–GATE3) is boosted to VINx + 5V, ensuring sufficient gate-source voltage (V_GS) to fully enhance low-threshold n-FETs-even when IN1, IN2, or IN3 operate near 0.7V. This capability enables efficient, low-dropout regulation in modern sub-1V digital systems.