Analog Devices Inc./Maxim Integrated MAX6888RETE+

Overview

The MAX6888RETE+ from Maxim Integrated is a quad-voltage, overvoltage/undervoltage supervisory IC with watchdog timer, active-low open-drain RESET/OV/WDO outputs, ±1.5% threshold accuracy, and 200ms reset timeout - used to monitor multiple DC-DC converter rails in telecom and server power systems.

For engineers reviewing the MAX6888RETE+ datasheet, MAX6888RETE+ pinout, MAX6888RETE+ application, or MAX6888RETE+ equivalent, this page delivers verified specifications, validated pin functions, confirmed timing behavior (102.4s initial / 1.6s normal watchdog), and real-world substitution guidance for multivoltage system design.

Technical Context

The MAX6888RETE+ implements four factory-set adjustable voltage detectors (IN1–IN4), each monitoring both undervoltage (UV) and overvoltage (OV) thresholds relative to a 0.6V internal reference with ±12.5% tolerance. Its virtual diode-OR power architecture selects the highest of IN1–IN4 (≥2.7V) to supply internal circuitry via VCC.

It features independent watchdog timing: 102.4s initial timeout for microprocessor initialization, then 1.6s normal timeout; WDO asserts low on timeout expiry and can be connected to MR to trigger RESET. All three outputs (RESET, OV, WDO) are active-low, open-drain with 0.4V max VOL at 4mA sink.

Key Specifications

Pinout & Package

MAX6888RETE+ uses a 5mm × 5mm × 0.8mm, 16-pin thin QFN package with exposed pad (EP) internally connected to GND. Pin numbering follows standard top-view orientation with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6887RETE+, the MAX6888RETE+ reduces pin count and layout complexity for four-rail systems while retaining identical threshold accuracy, watchdog timing, and thermal performance; compared with TPS3808G33DBVR, it delivers integrated multirail supervision, overvoltage response, and watchdog capability unavailable in single-channel alternatives.

Availability

MAX6888RETE+ is available at Aetrix Electronics and suitable for telecom infrastructure, server motherboard, and industrial networking applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6888RETE+ 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 communication applications.

The MAX6887/MAX6888 product line delivers multivoltage supervisory circuits optimized for telecom, server, and storage systems requiring coordinated reset, overvoltage protection, and watchdog supervision across multiple DC-DC rails.

FAQ

What voltage thresholds does the MAX6888RETE+ monitor on its four inputs?

The MAX6888RETE+ has factory-set undervoltage and overvoltage thresholds of 0.527V and 0.673V respectively on all four inputs (IN1–IN4). These are referenced to an internal 0.6V bandgap and support external resistor dividers to monitor higher rails - for example, a 1.2V supply can be scaled to 0.527V using R1/R2 = 1.28. The MAX6888RETE+ datasheet Table 2 confirms these values for the "RETE" variant.

Can the MAX6888RETE+ be powered from a dedicated VCC supply instead of the monitored rails?

Yes - the MAX6888RETE+ can be powered via the VCC pin, but only if VCC is at least 200mV higher than any voltage applied to IN1–IN4 and is brought up first. When all INx inputs are configured as adjustable (as in MAX6888RETE+), VCC must be externally supplied to ensure proper operation. The MAX6888RETE+ internal power architecture defaults to VCC in this configuration per datasheet Note 4.

How does the watchdog timer behave during power-up of the MAX6888RETE+?

At power-up, the MAX6888RETE+ asserts WDO high after a 2.5ms power-up delay (tD-PO), then immediately starts the 102.4s initial watchdog timeout period. This allows microprocessors time to initialize before supervision begins. After the first WDI toggle, it switches to the 1.6s normal timeout. The MAX6888RETE+ timing diagram Figure 3 explicitly defines this two-phase startup sequence.

Is the MAX6888RETE+ pin-compatible with other variants in the MAX6888 family?

Yes - all MAX6888 variants, including MAX6888RETE+, use the identical 16-pin thin QFN package with standardized pinout per the datasheet Pin Configurations diagram. IN1–IN4, RESET, WDO, OV, MR, MARGIN, WDI, VCC, BP, GND, and N.C. positions are fixed across the family. The MAX6888RETE+ differs only in threshold programming, not mechanical or electrical pin compatibility.

Does the MAX6888RETE+ require external pull-up resistors on its open-drain outputs?

Yes - RESET, OV, and WDO are active-low open-drain outputs and require external pull-up resistors to their respective logic supply voltages (e.g., 3.3V or 5V). Typical values range from 4.7kΩ to 10kΩ. The MAX6888RETE+ datasheet Pin Description section explicitly states "an external pullup resistor is required" for RESET and OV, and WDO behaves identically.