NXP Semiconductors MK21DX128AVLK5

Overview

MK21DX128AVLK5 from NXP Semiconductors (formerly Freescale) is a 32-bit ARM Cortex-M4 microcontroller with DSP extensions, operating at up to 50 MHz, featuring 128 KB program flash, 64 KB RAM, and FlexMemory architecture. It integrates USB OTG, dual SPI/I²C, four UARTs, 16-bit SAR ADC, and hardware crypto engines (AES, SHA-256), targeting industrial control and connected sensor nodes requiring deterministic real-time response and secure firmware updates.

For engineers reviewing the MK21DX128AVLK5 datasheet, MK21DX128AVLK5 pinout, MK21DX128AVLK5 application, or MK21DX128AVLK5 equivalent, key selection criteria include its -40°C to 105°C extended temperature rating, 80-pin LQFP package with validated low-leakage stop modes (as low as 0.36 µA in VLLS0), and FlexNVM-based field-upgradable storage capability.

Technical Context

This MCU implements the ARMv7E-M architecture with single-cycle DSP instructions and a tightly coupled memory subsystem supporting zero-wait-state execution at 50 MHz. Its clock system combines a 3–32 MHz crystal oscillator, 32 kHz RTC crystal input, and multi-purpose clock generator with internal FLL and PLL for flexible frequency synthesis across run and low-power modes.

The device uses FlexMemory technology-dedicated 64 KB FlexNVM partitioned into EEPROM-like emulated sectors and 4 KB FlexRAM for nonvolatile data logging without flash wear leveling overhead. Security modules include tamper detection, 128-bit unique ID, and hardware-accelerated cryptographic primitives compliant with FIPS PUB 197 and 180-4 standards.

Key Specifications

Pinout & Package

Package: 80-pin LQFP (12 mm × 12 mm), RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MK21DX128AVLK5, MK22FN512VLH12 offers greater code density and speed but sacrifices FlexMemory's wear-leveling-free data logging, while K22F51212 adds floating-point capability at the cost of higher static power and package incompatibility - making MK21DX128AVLK5 optimal for cost-sensitive, battery-operated systems requiring robust nonvolatile parameter storage.

Availability

MK21DX128AVLK5 is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and automotive body electronics requiring stable component supply, long-term lifecycle assurance, and extended temperature operation.

Supply support for MK21DX128AVLK5 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, with roots in Freescale's Kinetis portfolio.

The Kinetis K21 series was designed specifically for cost-optimized, low-power industrial and consumer applications demanding rich analog integration, USB connectivity, and hardware security - positioning MK21DX128AVLK5 as a balanced solution between performance, peripheral richness, and energy efficiency.

FAQ

What is the maximum operating frequency of the MK21DX128AVLK5?

The MK21DX128AVLK5 operates at a maximum system and core clock frequency of 50 MHz, as specified in the K21 Sub-Family Data Sheet Rev. 4.1. This frequency is achievable across the full -40°C to +105°C ambient temperature range and 1.71–3.6 V supply voltage, with the MCG configured in FEI or PEE mode. The MK21DX128AVLK5 sustains this speed while running from flash with cache enabled and all peripherals active.

Does the MK21DX128AVLK5 support hardware encryption?

Yes, the MK21DX128AVLK5 includes a dedicated hardware crypto engine supporting AES-128/256, DES/3DES, SHA-1, SHA-256, and MD5 algorithms. This accelerator offloads cryptographic operations from the Cortex-M4 core, reducing execution time by over 90% compared to software-only implementations. The MK21DX128AVLK5 also features a hardware random-number generator and tamper-detect circuitry for secure key provisioning and firmware validation.

What package type and pin count does the MK21DX128AVLK5 use?

The MK21DX128AVLK5 uses an 80-pin LQFP package (12 mm × 12 mm), identified by the "LK" suffix in its part number per the K21 naming convention. This package provides full access to all peripherals including USB DP/DM, multiple UART/SPI/I²C interfaces, 16 ADC channels, and GPIO with interrupt capability on every pin. The MK21DX128AVLK5's pinout is documented in Section 8.2 of the K21 Sub-Family Data Sheet.

How much FlexMemory does the MK21DX128AVLK5 include?

The MK21DX128AVLK5 includes 64 KB of FlexNVM and 4 KB of FlexRAM, both part of its FlexMemory subsystem. FlexNVM can be partitioned to emulate EEPROM with byte-write capability and no wear leveling overhead, while FlexRAM serves as fast, nonvolatile data storage that retains values across power cycles without flash programming delays. This architecture is confirmed in the "Memories and memory interfaces" section of the K21 Sub-Family Data Sheet.

What is the lowest power consumption mode supported by the MK21DX128AVLK5?

The MK21DX128AVLK5 supports Very Low-Leakage Stop Mode 0 (VLLS0) with typical current draw of 0.36 µA at 3.0 V and -40°C to 25°C ambient, as measured with the POR detect circuit disabled. In this mode, the RTC remains active via VBAT, RAM contents are retained, and wake events include pin interrupts, RTC alarms, or LLWU inputs. This ultra-low power state makes the MK21DX128AVLK5 suitable for decade-long battery operation in remote sensor applications.