Analog Devices Inc./Maxim Integrated MAX17320G22+

Overview

MAX17320G22+ from Analog Devices is a stand-alone 2S–4S lithium-ion/polymer battery fuel gauge IC with integrated protector, internal self-discharge detection, SHA-256 authentication, and ModelGauge m5 EZ algorithm. It delivers ±1% state-of-charge accuracy over life, monitors voltage/current/temperature across up to four cells, and controls external high-side N-FETs for overvoltage, overcurrent, short-circuit, and thermal protection in smart battery packs.

For engineers reviewing the MAX17320G22+ datasheet, MAX17320G22+ pinout, MAX17320G22+ application, or MAX17320G22+ equivalent, key selection considerations include its 38μA quiescent current in active FET-enabled mode, internal cell balancing capability, configurable always-on LDO (AOLDO*), dynamic power estimation, and SBS 1.1-compatible register set for seamless integration into portable medical and consumer battery systems.

Technical Context

The MAX17320G22+ implements a dual-sensing architecture: coulomb counting for short-term capacity tracking and voltage-based OCV modeling for long-term SoC stability, fused via Maxim's ModelGauge m5 EZ algorithm. It supports JEITA-compliant charging prescriptions and prequal charge control using the CHGFET for safe zero-volt recovery.

Protection logic operates independently of host communication via dedicated comparators and fault timers, enabling autonomous response to overvoltage (temperature-dependent thresholds), over/undertemperature, SmartEmpty™ undervoltage, and internal self-discharge events. Authentication uses a 160-bit secret key with per-device 64-bit ID for pack-level security.

Key Specifications

Pinout & Package

The MAX17320G22+ is packaged in a lead-free, 2.4mm × 2.6mm, 30-bump, 0.4mm pitch Wafer-Level Package (WLP), optimized for space-constrained battery pack PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fuel gauge with protection applications.

Compared with BQ40Z50-R1 and ISL94203, the MAX17320G22+ uniquely combines ±1% SoC accuracy, internal cell balancing, SHA-256 authentication, and dynamic power estimation in a 2.4mm × 2.6mm WLP-making it optimal for compact, secure, high-precision battery packs in regulated markets.

Availability

MAX17320G22+ is available at Aetrix Electronics and suitable for smartphones, medical wearables, and drone battery packs requiring stable component supply, long-term lifecycle support, and compliance with IEC 62133 and UL 2054 safety standards.

Supply support for MAX17320G22+ 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The MAX17320G22+ belongs to Analog Devices' ModelGauge™ m5 fuel gauge product line, engineered specifically for secure, high-accuracy, stand-alone battery management in space- and safety-constrained portable electronics.

FAQ

What is the primary function of the MAX17320G22+ in a battery pack?

The MAX17320G22+ serves as a stand-alone fuel gauge and protector for 2S–4S lithium-ion/polymer battery packs. It provides highly accurate state-of-charge estimation using the ModelGauge m5 EZ algorithm, enforces safety protections (overvoltage, overcurrent, temperature faults), detects internal self-discharge, and performs SHA-256 authentication. The MAX17320G22+ operates autonomously without host intervention and supports both I²C/SMBus and 1-Wire interfaces.

Does the MAX17320G22+ require external components for cell balancing?

No, the MAX17320G22+ integrates balancing FETs and performs passive cell balancing internally during charging. It does not require external balancing resistors or driver circuitry. Balancing thresholds and timing are programmable via registers such as nBalTh (1D4h), and the IC automatically sequences balancing across cells based on voltage differentials. This simplifies PCB layout and reduces BOM cost compared to solutions requiring discrete balancing components.

How does the MAX17320G22+ achieve ±1% state-of-charge accuracy?

The MAX17320G22+ achieves ±1% SoC accuracy by combining coulomb counting for short-term precision with voltage-based open-circuit voltage (OCV) modeling for long-term stability-fused intelligently via the ModelGauge m5 EZ algorithm. It continuously compensates for cell aging, temperature effects, and discharge rate variations using real-time measurements from up to four thermistors and precision current sensing. Calibration is not required, and accuracy is maintained across the full life cycle of the battery.

What protection features does the MAX17320G22+ provide, and how are they enforced?

The MAX17320G22+ provides autonomous hardware-based protection against overvoltage, undervoltage (SmartEmpty™), overcurrent (fast/slow modes), short-circuit, overtemperature, undertemperature, overcharge, and internal self-discharge. These protections are enforced using dedicated analog comparators and fault timers that operate independently of the host interface. When triggered, the IC asserts CHG/DIS signals to disable external high-side N-FETs-ensuring fail-safe behavior even if the host MCU is unresponsive or powered down.

Can the MAX17320G22+ be used in battery packs with fewer than four cells?

Yes, the MAX17320G22+ supports 2S, 3S, and 4S lithium-ion/polymer configurations. Its pinout and internal logic are designed to scale across this range: unused CELLx pins (e.g., CELL3/CELL4 in a 2S pack) are simply left unconnected or tied appropriately per layout guidelines. Protection thresholds, balancing behavior, and fuel gauge modeling automatically adapt to the configured cell count via the nPackCfg register (1B5h), ensuring correct operation without firmware rework.