Analog Devices Inc./Maxim Integrated MAX17270ETE+T

Overview

The MAX17270ETE+T from Maxim Integrated is a nanopower, triple-output, single-inductor multiple-output (SIMO) buck-boost DC-DC regulator designed for space-constrained wearable electronics. It delivers 1.2V/80mA, 1.8V/75mA, and 3.3V/50mA outputs from a 2.7V–5.5V input using one 2.2µH inductor, achieves up to 85% efficiency, and draws only 1.3µA quiescent current with all three outputs enabled.

For engineers reviewing the MAX17270ETE+T datasheet, MAX17270ETE+T pinout, MAX17270ETE+T application, or MAX17270ETE+T equivalent, key selection criteria include its SIMO architecture enabling battery-voltage-range coverage (output above/below/equal to input), programmable per-channel peak current limits, ultra-low shutdown current (330nA), 16-pin TQFN package (3mm × 3mm × 0.75mm), and enable-input-based output control without I²C interface.

Technical Context

The MAX17270ETE+T implements a proprietary time-interleaved SIMO control scheme that dynamically allocates switching cycles among three independent buck-boost outputs using shared LXA/LXB inductor terminals. Each output is configured via external RSEL resistors (0.8V–4.6V range), with peak current limits set by resistor tolerance (±1%) and value (e.g., 56.2kΩ → 1.1A).

It features dedicated EN1/EN2/EN3 inputs for per-output enable/disable, soft-start with 1.2mV/µs ramp rate, overload and thermal protection, and operates across –40°C to +85°C. Unlike the MAX17271, it lacks I²C, ON button, IRQB, RSTB, SDA, SCL, VIO, or active discharge-making it a fixed-function, resistor-programmed variant.

Key Specifications

Pinout & Package

Package: 16-pin TQFN (3mm × 3mm × 0.75mm, outline 21-0136, land pattern 90-0032). RoHS-compliant, moisture-sensitive level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-output power management applications.

Compared with MAX17271ETE+T, the MAX17270ETE+T trades programmability for lower BOM cost and simpler layout; versus TPS65270PWPR, it enables full Li-ion voltage utilization and 30% smaller footprint - critical for sub-1000mm² wearable PCBs.

Availability

The MAX17270ETE+T is available at Aetrix Electronics and suitable for Bluetooth headsets, fitness bands, and smart watches requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX17270ETE+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

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and power management ICs for demanding applications in industrial, medical, communications, and consumer markets.

The MAX17270ETE+T belongs to Maxim's nanoPower SIMO regulator product line, engineered specifically for ultra-low-power, space-constrained wearable devices where battery life and miniaturization are primary design constraints.

FAQ

What is the function of the RSEL pins on the MAX17270ETE+T?

The RSEL1, RSEL2, and RSEL3 pins on the MAX17270ETE+T are voltage programming inputs that set each output's regulated voltage and corresponding peak inductor current limit. Each pin connects to GND via a precision ±1% resistor; for example, a 56.2kΩ resistor on RSEL1 configures OUT1 to 0.8V with 1.1A current limit. The MAX17270ETE+T does not support I²C or digital configuration - all settings are resistor-determined at power-on.

Does the MAX17270ETE+T support output voltages above the input voltage?

Yes, the MAX17270ETE+T supports output voltages both above and below the input voltage due to its buck-boost SIMO architecture. For instance, with a 2.7V–5.5V input, it can deliver a stable 3.3V output even when the battery drops to 2.7V, and also generate 1.2V when input is 3.7V. This eliminates the need for separate boost or buck converters in single-battery wearable systems.

What is the maximum load current supported by each output of the MAX17270ETE+T?

The MAX17270ETE+T supports up to 80mA on OUT1, 75mA on OUT2, and 50mA on OUT3 under typical conditions (TJ = 25°C, VIN = 3.7V). These values assume appropriate RSEL resistor selection (e.g., 56.2kΩ → 1.1A peak limit) and proper 10µF output capacitance per rail. Load capability scales with programmed peak current limit and thermal derating above 70°C ambient.

How does the ultra-low-power mode (ULPM) operate in the MAX17270ETE+T?

The MAX17270ETE+T automatically enters ultra-low-power mode (ULPM) on any output with very light load (e.g., <100µA). In ULPM, the output voltage is biased 2.5% higher than nominal (e.g., 1.23V instead of 1.2V) to minimize undershoot during sudden load steps. This mode reduces quiescent current to sub-µA levels per channel while maintaining regulation - critical for multi-week standby in hearables and fitness trackers.

Can the MAX17270ETE+T be used with a 2.2µH inductor other than Coilcraft XFL4020-222ME?

Yes, the MAX17270ETE+T is qualified with the Coilcraft XFL4020-222ME but supports other 2.2µH shielded power inductors meeting key specifications: DC resistance ≤120mΩ, saturation current ≥1.5A, and self-resonant frequency >20MHz. Layout must maintain tight coupling between LXA and LXB traces, minimize loop area, and use solid PGND plane beneath the IC to ensure stable SIMO operation and low EMI.