Analog Devices Inc./Maxim Integrated MAX34446ETL+

Overview

MAX34446ETL+ from Maxim Integrated is a PMBus-compliant power-supply data logger IC that monitors up to four voltage or current channels and three temperature sensors (two remote diodes + one internal) using a differential 12-bit ADC. It detects overvoltage, undervoltage, overcurrent, and overtemperature conditions, logs fault-triggered real-time operating data into on-chip nonvolatile flash memory, and operates from 2.7V to 5.5V across –40°C to +105°C - used in server power rail health monitoring.

For engineers reviewing the MAX34446ETL+ datasheet, MAX34446ETL+ pinout, MAX34446ETL+ application, or MAX34446ETL+ equivalent, key selection considerations include its 40-pin TQFN package, PMBus 1.1 command support, 37ms nonvolatile log write time, 20,000-flash endurance, and integrated power-good/fault outputs for autonomous fault response in telecom and industrial power systems.

Technical Context

The MAX34446ETL+ implements a dedicated PMBus slave interface with SMBus 1.1 physical layer compliance, supporting PAGE-based channel addressing for independent configuration of six ADC inputs (ADC0–ADC5). Its internal 4MHz system clock drives a differential 12-bit ADC with ±0.6% full-scale drift and 300µV LSB resolution, enabling precise voltage/current measurement and thermal diode sensing with ±3.5°C remote accuracy over –40°C to +105°C.

It features dual regulated supplies (REG18 for digital logic, REG25 for analog circuitry), programmable fault thresholds per channel, and hardware-triggered logging via LOG/ENABLE pins. Fault reporting occurs through eight open-drain FAULTn outputs and six push-pull PGn outputs, each configurable for active-high or open-drain operation via PMBus commands.

Key Specifications

Pinout & Package

40-pin TQFN (6mm × 6mm, 0.75mm height) with exposed pad (EP) connected to VSS for thermal and electrical grounding.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX34447ETL+, the MAX34446ETL+ omits internal EEPROM but retains identical ADC performance, fault logging latency, and PMBus command compatibility - making it ideal for cost-sensitive, logging-centric designs. Against LTC2978B-1, it trades channel count and hot-swap capability for lower power, smaller footprint, and deterministic flash-based fault capture.

Availability

MAX34446ETL+ is available at Aetrix Electronics and suitable for base station power monitoring, industrial PLC power health, network switch rail telemetry, and server PSU health logging requiring stable component supply and long-term lifecycle support.

Supply support for MAX34446ETL+ 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, mixed-signal, and power management ICs for demanding industrial, communications, and computing applications.

The MAX34446ETL+ belongs to Maxim's PMBus power-monitoring product line, engineered specifically for autonomous, nonvolatile fault logging in high-reliability power systems where host-independent diagnostics are critical.

FAQ

What is the primary function of the MAX34446ETL+?

The MAX34446ETL+ is a PMBus-compliant power-supply data logger IC that autonomously monitors up to four voltage or current channels and three temperature sensors, detects threshold violations, and logs real-time operating data into on-chip nonvolatile flash memory. Its core function is deterministic, host-independent fault capture - the MAX34446ETL+ performs this without firmware intervention, using hardware triggers like the LOG pin or PMBus commands such as MFR_NV_FAULT_LOG.

Does the MAX34446ETL+ require an external clock source?

No, the MAX34446ETL+ does not require an external clock source. It integrates a 4MHz internal system clock (fMOSC) with ±6.5% error over –40°C to +25°C and ±4% over –20°C to +105°C, which drives the ADC, PMBus interface timing, and internal state machine. This eliminates BOM cost and layout complexity associated with external crystals or oscillators - the MAX34446ETL+ achieves full functionality with only VDD, VSS, and PMBus connections.

How many temperature sensors can the MAX34446ETL+ monitor simultaneously?

The MAX34446ETL+ can monitor three temperature sensors concurrently: one internal die sensor and two remote thermal diodes connected to ADC4 and ADC5. Remote diode accuracy is ±3.5°C over –40°C to +105°C, while internal sensor error is ±3.5°C over the same range. All temperature readings are accessible via PMBus commands including READ_TEMPERATURE_1 and MFR_TEMPERATURE_PEAK - the MAX34446ETL+ processes these natively without host-side compensation.

What is the nonvolatile memory endurance and data retention of the MAX34446ETL+?

The MAX34446ETL+ uses on-chip flash memory rated for 20,000 write cycles and 100 years of data retention at +50°C. Nonvolatile log operations - including STORE_DEFAULT_ALL, MFR_NV_FAULT_LOG writes, and automatic fault-triggered captures - complete in 37ms (write), 40ms (overwrite), or 775ms (full delete). This endurance and retention specification is guaranteed across the full operating temperature range (–40°C to +105°C), ensuring reliable logging in long-life infrastructure equipment - the MAX34446ETL+ maintains data integrity without periodic refresh or backup.

Can the MAX34446ETL+ operate with standard I²C hosts, or is a PMBus-specific master required?

The MAX34446ETL+ is fully compatible with standard I²C and SMBus hosts due to its I²C/SMBus-compatible physical interface (SDA/SCL), but full functionality requires a PMBus-aware master. While basic read/write transactions work with generic I²C controllers, PMBus-specific commands (e.g., READ_VOUT, MFR_NV_FAULT_LOG, POWER_GOOD_ON) rely on the DIRECT data format and command structure defined in PMBus 1.1. Host firmware must implement the m/b/R coefficients from Table 3 to interpret values correctly - the MAX34446ETL+ does not auto-negotiate format and expects compliant PMBus protocol handling.