Analog Devices Inc./Maxim Integrated MAX17222ELT+T

Overview

The MAX17222ELT+T from Analog Devices is an ultra-low-quiescent-current synchronous boost DC-DC converter with 500mA peak inductor current limit, True Shutdown™, and single-resistor-selectable output (1.8V–5V). It starts up from as low as 0.88V and operates down to 400mV input, delivering regulated power to optical heart-rate monitoring LEDs and supercapacitor-backed RTCs in primary-cell wearable systems.

For engineers reviewing the MAX17222ELT+T datasheet, MAX17222ELT+T pinout, MAX17222ELT+T application, or MAX17222ELT+T equivalent, key selection criteria include its 300nA quiescent supply current into OUT, 0.5nA shutdown current, 95% peak efficiency, 2mm × 2mm μDFN-6 package, and enable transient protection enabling stable regulation at 400mV input under load.

Technical Context

The MAX17222ELT+T employs a fixed-on-time, current-limited PFM control scheme with automatic mode switching between ultra-low-power mode (ULPM), low-power mode (LPM), and high-power mode (HPM) based on load current. Its 300ns maximum on-time and 500mA N-channel switch current limit enable efficient operation across microamp to ~200mA loads.

True Shutdown™ disconnects OUT from IN with no forward or reverse current path, supported by internal clamping diodes on LX and validated leakage specs: 0.5nA total shutdown current (IN + LX), 0.3nA LX leakage at 1.5V, and reverse-current blocking from 0V to 5V at OUT.

Key Specifications

Pinout & Package

The MAX17222ELT+T is packaged in a 2mm × 2mm, 6-pin μDFN (package code L622+1C) with wettable flanks, optimized for automated optical inspection and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost converter applications.

Compared with TPS61291DRVR and XC9285B18ER-G, the MAX17222ELT+T uniquely combines 0.5nA shutdown, True Shutdown isolation, and ETP-making it the only choice for primary-cell wearables requiring guaranteed 400mV-in regulation and zero reverse leakage during backup modes.

Availability

The MAX17222ELT+T is available at Aetrix Electronics and suitable for optical heart-rate monitoring, supercapacitor-backed RTCs, and primary-cell portable medical sensors requiring stable component supply across long production lifecycles.

Supply support for MAX17222ELT+T 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 (acquired Maxim Integrated in 2021) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial, automotive, and healthcare markets.

The MAX17220–MAX17225 family was designed specifically for ultra-low-power battery-operated devices-prioritizing nanoamp quiescent current, minimal solution size, and robust operation from deeply discharged primary cells.

FAQ

What is the minimum input voltage required for the MAX17222ELT+T to start up?

The MAX17222ELT+T has a typical startup input voltage of 0.88V under standard test conditions (RL ≥ 3kΩ, TA = +25°C). This allows reliable cold-start from nearly depleted primary cells such as silver-oxide or alkaline AAA batteries. The device then continues operating down to 400mV input once started, thanks to its Enable Transient Protection feature.

How does the RSEL pin work on the MAX17222ELT+T, and what resistor value sets 3.0V output?

The MAX17222ELT+T uses a single resistor from SEL to GND to set output voltage; the part samples this resistance during a ≤600µs detection window at startup. For 3.0V output, a 133kΩ ±1% resistor is required, per the official RSEL Selection Table. No current flows through RSEL during normal operation-eliminating static power loss.

Does the MAX17222ELT+T support true output disconnect in shutdown mode?

Yes-the MAX17222ELT+T implements True Shutdown™, which physically disconnects the output from the input using internal MOSFETs. This results in 0.5nA total shutdown current (IN + LX), zero forward or reverse current flow, and guaranteed reverse-current blocking from 0V to 5V at the OUT pin-critical for supercapacitor backup integrity.

What package type and dimensions does the MAX17222ELT+T use?

The MAX17222ELT+T is supplied in a 2mm × 2mm, 6-pin μDFN package (outline 21-0164, land pattern 90-0004) with wettable flanks. It features a 0.5mm pin pitch and exposes the die pad on the bottom for thermal conduction-enabling compact, thermally robust layouts in space-constrained wearables and medical patches.

Can the MAX17222ELT+T operate efficiently at very light loads, such as 1µA?

Yes-the MAX17222ELT+T automatically enters ultra-low-power mode (ULPM) below ~1.5mA load, reducing switching frequency to as low as 11.5Hz while maintaining ±2.5% output regulation. Its 300nA quiescent supply current into OUT ensures >99% of input power reaches the load even at 1µA, making it ideal for always-on environmental sensors and RTC backup rails.