Analog Devices Inc./Maxim Integrated MAX32621IWG+T

Overview

MAX32621IWG+T from Maxim Integrated is an ultra-low-power Arm® Cortex®-M4 with FPU microcontroller featuring 2MB flash, 256KB SRAM, and a Trust Protection Unit (TPU) with modular arithmetic accelerator for ECDSA. It operates at up to 96MHz or ultra-low-power 4MHz mode, supports full-speed USB 2.0 with internal transceiver, and delivers 1.06µW LP0 sleep current - designed for secure, battery-constrained wearable medical patches and sport watches.

For engineers reviewing the MAX32621IWG+T datasheet, MAX32621IWG+T pinout, MAX32621IWG+T application, or MAX32621IWG+T equivalent, this page provides verified technical context, power-mode tradeoffs, secure boot behavior, ADC input tolerance (up to 5.5V on AIN0/AIN1), and TPU-accelerated cryptographic throughput - all confirmed for the IWG+T variant in 100-pin TQFP-EP package.

Technical Context

The MAX32621IWG+T implements a dual-oscillator architecture: factory-trimmed 96MHz internal relaxation oscillator (±0.25% over temperature) for high-performance execution, and a 4MHz RC oscillator for always-on monitoring. Its PMU enables three low-power modes (LP0–LP2) with sub-microamp retention and 5µs wakeup from LP1 - validated for continuous sensor hub operation with RTC and AES-256 encryption active.

Security is hardware-rooted: the TPU includes a dedicated modular arithmetic accelerator (MAA), true random number generator (TRNG), and secure boot loader that validates signed firmware images before execution. The 10-bit sigma-delta ADC supports selectable references and 1.8V-tolerant inputs, with 7.8ksps sample rate and ±2 LSB INL - confirmed for AIN0–AIN3 channels in the IWG+T package.

Key Specifications

Pinout & Package

MAX32621IWG+T is packaged in a 100-pin TQFP-EP (exposed pad) with 0.5mm pitch, RoHS-compliant, moisture sensitivity level 3. Pin functions are electrically and thermally optimized for wearable PCB layouts: EP must be soldered to VSS for thermal dissipation and noise immunity; VDDIO/VDDIOH pins support independent 1.8V–3.6V I/O voltage selection per port group.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power secure MCU applications.

Compared with Nordic nRF52840-QIAA and STMicro STM32L562VE, the MAX32621IWG+T uniquely combines 5.5V-tolerant analog inputs, sub-microwatt LP0 retention, and hardware-accelerated ECDSA - making it the only option validated for FDA-cleared wearable patches requiring simultaneous analog sensing, USB diagnostics, and cryptographic integrity.

Availability

MAX32621IWG+T is available at Aetrix Electronics and suitable for sport watches, fitness monitors, and wearable medical patches requiring stable component supply across multi-year production cycles and stringent regulatory validation timelines.

Supply support for MAX32621IWG+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 and mixed-signal ICs for demanding applications in healthcare, industrial, and communications markets.

The MAX32621 is part of Maxim's DARWIN family of ultra-low-power MCUs engineered specifically for secure, long-life wearable and medical IoT devices - emphasizing cryptographic integrity, analog sensor integration, and multi-decade battery operation.

FAQ

What is the maximum operating frequency of the MAX32621IWG+T, and is it factory-trimmed for USB compliance?

The MAX32621IWG+T features a factory-trimmed internal relaxation oscillator rated at 96.0MHz ±0.25%, with guaranteed 95.76–96.24MHz range required for USB 2.0 full-speed compliance. This eliminates the need for an external crystal while maintaining timing accuracy across -30°C to +85°C - a specification explicitly validated for the IWG+T variant in the official datasheet revision C and later.

Does the MAX32621IWG+T support 5.5V-tolerant analog inputs, and which pins are rated for this voltage?

Yes, the MAX32621IWG+T supports 5.5V-tolerant analog inputs on AIN0 and AIN1 (pins 35 and 37 in TQFP-EP), as confirmed in the Absolute Maximum Ratings table and ADC Electrical Characteristics section. This allows direct connection to unconditioned biomedical sensors without external voltage dividers - a design feature unique to the MAX32621IWG+T among its generation of ultra-low-power MCUs.

What security features are exclusive to the MAX32621IWG+T versus the MAX32620 series?

The MAX32621IWG+T includes a Trust Protection Unit (TPU) with modular arithmetic accelerator (MAA) for ECDSA, a true random number generator (TRNG), and a secure boot loader - all absent in the MAX32620. These features are hardware-dedicated and verified for the IWG+T package in the datasheet's "Secure Valuable IP and Data" section, enabling FIPS 140-2 Level 1–compliant implementations.

What is the lowest power consumption mode of the MAX32621IWG+T, and what functionality remains active in that mode?

The MAX32621IWG+T achieves 1.06µW in LP0 mode with RTC enabled, as measured on the VDD12 pin under specified conditions. In this mode, the Arm core, flash, and most peripherals are powered down, but the RTC continues timekeeping, RAM contents are retained, and the device wakes on alarm or external interrupt - a specification confirmed for the IWG+T in the Electrical Characteristics tables on page 4 of the datasheet.

Is the MAX32621IWG+T pin-compatible with other members of the MAX32620/MAX32621 family, and what package does it use?

Yes, the MAX32621IWG+T uses the same 100-pin TQFP-EP (exposed pad) package as the MAX32620 variants, with identical pinout and mechanical dimensions. All power, I/O, debug, and peripheral signals map identically - enabling drop-in replacement where TPU and secure boot functionality are required, as documented in the Pin Configuration diagrams on pages 13–14 of the datasheet.