NXP Semiconductors MK21DX256AVMC5

Overview

MK21DX256AVMC5 from NXP Semiconductors (formerly Freescale) is a 32-bit ARM Cortex-M4 microcontroller with DSP extensions, operating at up to 50 MHz, featuring 256 KB program flash, 64 KB RAM, and FlexMemory (4 KB FlexRAM + 64 KB FlexNVM). It integrates USB OTG, dual SPI/I²C, four UARTs, 16-bit SAR ADC, real-time clock, and hardware encryption (AES/SHA-256), targeting industrial control and secure embedded systems.

For engineers reviewing the MK21DX256AVMC5 datasheet, MK21DX256AVMC5 pinout, MK21DX256AVMC5 application, or MK21DX256AVMC5 equivalent, key selection considerations include its -40°C to 105°C extended temperature grade, 1.71–3.6 V supply range, low-power stop modes down to 0.36 µA, and support for secure boot via tamper detection and hardware RNG.

Technical Context

This Kinetis K21 sub-family MCU implements an ARM Cortex-M4 core with single-cycle DSP instructions and a Memory Protection Unit (MPU), paired with a multi-purpose clock generator supporting crystal oscillators (3–32 MHz and 32 kHz), internal reference, and fractional PLL. Its memory subsystem includes unified flash with EEPROM-like FlexNVM emulation and configurable FlexRAM for data logging or NV storage.

The peripheral set is optimized for deterministic real-time control: eight-channel PWM timer with motor control features, two general-purpose timers with quadrature decode, programmable delay block, and carrier modulator transmitter. Analog integration comprises a 16-bit SAR ADC with hardware averaging and two analog comparators with integrated 6-bit DACs and programmable references.

Key Specifications

Pinout & Package

Package: 121-pin MAPBGA (8 mm × 8 mm, 0.5 mm pitch, MC suffix). Pinout validated per K21 Sub-Family Data Sheet Rev. 4.1, Section 8.2 (MK21DX256VMC5 variant mapping confirmed for identical pin assignment).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MK21DX256AVMC5, MKE15Z256VLH7 offers lower cost and power but sacrifices DSP capability, USB OTG, and secure storage; MIMXRT1021DAG5A delivers orders-of-magnitude higher throughput but requires external flash and lacks integrated FlexMemory for robust data logging.

Availability

MK21DX256AVMC5 is available at Aetrix Electronics and suitable for industrial control, smart metering, and medical device applications requiring stable component supply, long-term lifecycle assurance, and extended temperature operation.

Supply support for MK21DX256AVMC5 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 deep expertise in ARM-based microcontrollers and edge AI processing.

The Kinetis K21 family was designed specifically for cost-sensitive, low-power industrial and medical applications demanding robust security, analog precision, and flexible memory architecture-exemplified by the MK21DX256AVMC5's integrated FlexMemory and hardware crypto engines.

FAQ

What is the maximum operating frequency of the MK21DX256AVMC5?

The MK21DX256AVMC5 operates at a maximum core frequency of 50 MHz, supported by its ARM Cortex-M4 core with DSP extensions. This frequency is achievable across the full -40°C to +105°C temperature range and 1.71–3.6 V supply voltage, as verified in the K21 Sub-Family Data Sheet Rev. 4.1, Table 9. The device maintains timing compliance even when USB full-speed mode is active, which constrains the system clock to ≥20 MHz.

Does the MK21DX256AVMC5 include hardware encryption capabilities?

Yes, the MK21DX256AVMC5 integrates dedicated hardware acceleration for DES, 3DES, AES (128/256-bit), MD5, SHA-1, and SHA-256 cryptographic algorithms, as documented in Section 5.5 of the K21 Sub-Family Data Sheet. This enables secure firmware updates and data-at-rest protection without consuming CPU cycles, and is complemented by a hardware random-number generator and tamper-detect circuitry for comprehensive security.

What package type does the MK21DX256AVMC5 use?

The MK21DX256AVMC5 uses a 121-pin MAPBGA package (8 mm × 8 mm, 0.5 mm pitch), identified by the "MC" suffix in its part number per Section 2.3 of the K21 Sub-Family Data Sheet. This package is footprint-compatible with other K21 devices in the MC variant (e.g., MK21DX128VMC5), enabling scalable design reuse across memory configurations.

How much FlexMemory does the MK21DX256AVMC5 provide?

The MK21DX256AVMC5 provides 64 KB of FlexNVM and 4 KB of FlexRAM, as specified in the "Memories and memory interfaces" section of the K21 Sub-Family Data Sheet. This FlexMemory subsystem allows the 64 KB FlexNVM region to be configured as data flash (emulating EEPROM) or program flash, while the 4 KB FlexRAM serves as fast, non-volatile scratchpad memory for critical variables or logging buffers.

Is the MK21DX256AVMC5 qualified for automotive applications?

The MK21DX256AVMC5 is rated for -40°C to +105°C operation and meets industrial reliability standards, but it is not AEC-Q100 qualified. Its temperature range and robust feature set (e.g., watchdogs, CRC, low-power modes) make it suitable for under-hood body control modules or infotainment peripherals where full automotive qualification is not mandated, though designers must perform system-level validation per ISO 26262 ASIL-B if used in safety-critical functions.