MK21FX512VLQ12 - 120MHz Cortex-M4 MCU 512KB | NXP
MPN: MK21FX512VLQ12 ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.42 | $8.42 |
| 10 | $7.58 | $75.80 |
| 100 | $6.74 | $674.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.55 | $5,550.00 |
MK21FX512VLQ12 Overview
A microcontroller unit (MCU) is a single-chip embedded processor that integrates a CPU core, memory arrays, and a rich set of peripherals on one die, sitting within the broader hierarchy of semiconductor devices as a system-on-chip for embedded control. Unlike a general-purpose processor, an MCU executes dedicated firmware for real-time control, sensing, and connectivity tasks in a power-efficient manner.
Key features of the MK21FX512VLQ12 include hardware cryptography and tamper detection for security-sensitive designs, a USB full-/low-speed On-The-Go controller with on-chip transceiver and device charger-detect capability, and a floating-point unit inherited from the Cortex-M4 core for efficient DSP and motor-control mathematics.
The communication peripheral set comprises two SPI modules, two I2C modules, four UART modules, and an I2S audio interface, enabling multi-bus system designs without external expanders. Analog integration covers high-speed ADCs and comparators per the K21 sub-family datasheet, and flexible clocking supports low-power operation targets typical of cost-sensitive industrial applications.
Typical applications include industrial automation and control nodes, IoT edge devices, robotics controllers, consumer appliances, and secure portable equipment where the anti-tamper and hardware encryption engine reduces bill-of-materials cost for security.
Design consideration: as this device is listed NRND (Not Recommended for New Designs) by NXP, new designs should evaluate pin-compatible successors or confirm long-term supply before committing; the 144-LQFP requires careful decoupling of the multiple VDD/VSS pairs per the manufacturer datasheet.
This page synthesizes distributor listings, lifecycle status, drop-in alternatives, and practical design guidance not found in the manufacturer datasheet alone, with pricing verified as of 2026-10-18.
Drop-in alternatives for MK21FX512VLQ12 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MK21FX512VLQ12 (same form factor and footprint) — differing in Mounting Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MK21FX512VLQ10
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK21FN1M0VLQ12
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$9.2 / Unit
View Datasheet →MK21DX256VLQ5
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK21DN512VLQ5
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK22FX512VLQ12
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK21FX512VLQ12 Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M4 (Cortex-M4F) |
| Core Size | 32-bit |
| Maximum Clock Frequency | 120 MHz |
| Program Memory Size | 512 KB (512K x 8) Flash |
| FlexMem Size | 128 KB (configurable flash/EEPROM) |
| RAM Size | 128 KB |
| Package | 144-LQFP (20 x 20 mm) |
| Mounting Type | Surface Mount |
| USB Controller | USB full-/low-speed OTG with on-chip transceiver and charger detect |
| SPI Modules | 2 |
| I2C Modules | 2 |
| UART Modules | 4 |
| I2S Module | 1 |
| Security Features | Hardware encryption, tamper detection |
| MSL Level | 3 (168 Hours) |
| HTSUS Code | 8542.31.0001 |
| REACH Status | REACH Unaffected |
| Product Family | Kinetis K21 120 MHz (K21F sub-family) |
MK21FX512VLQ12 144-lqfp (20 x 20 mm) Pin Configuration Guide
Pin configuration for MK21FX512VLQ12 (144-lqfp (20 x 20 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MK21FX512VLQ12.
Refer to the datasheet for full pin configuration.
Typical Applications
MK21FX512VLQ12 is suitable for 6 applications: Industrial Automation and Control, IoT Edge Devices, Robotics Controllers, Secure Portable and Payment Devices, Consumer Appliances, Test and Measurement Equipment.
Industrial Automation and Control
The MK21FX512VLQ12 fits industrial control nodes where its 120 MHz Cortex-M4 with hardware FPU executes PID and field-oriented control loops deterministically, while four UARTs and two SPI modules link drives, sensors, and HMIs. The 128 KB SRAM buffers communication stacks and logging data, and industrial operating ratings support factory-floor environments. Designers should note the NRND status and plan migration paths for long-lifetime industrial programs; existing control boards benefit from the rich K21 peripheral mix without external interface chips.
Recommended
IoT Edge Devices
For IoT edge nodes, the MK21FX512VLQ12 combines a 120 MHz core with low-power operating modes typical of the Kinetis K21 family, so sensor sampling, protocol translation, and local decision logic run efficiently. The 512 KB flash holds wireless connectivity stacks and OTA bootloader code, while 128 KB FlexMem emulates EEPROM for calibration and configuration storage. Hardware encryption offloads TLS-style cipher workloads from firmware. USB OTG simplifies commissioning and firmware updates in the field via a standard connector.
Recommended
Robotics Controllers
Robotics motion controllers benefit from the MK21FX512VLQ12's 120 MHz Cortex-M4F floating-point core, which executes kinematics and servo loop mathematics in hardware rather than software emulation. Multiple SPI and UART channels coordinate encoders, motor drivers, and host links simultaneously, while high-speed ADCs sample current shunts for torque control. The 144-LQFP exposes ample GPIO for limit switches and safety interlocks. Its industrial portfolio heritage (Freescale Kinetis) provides mature toolchain and SDK support for robotics teams.
Recommended
Secure Portable and Payment Devices
The K21F sub-family's differentiator is on-chip hardware encryption plus tamper detection, making the MK21FX512VLQ12 attractive for portable terminals, metering, and licensed equipment that must protect keys and firmware. The USB OTG controller with charger detect enables both data transfer and charging negotiation from one port, important in battery-powered handhelds. The 128 KB FlexMem stores transaction logs in emulated EEPROM with wear leveling. Its 120 MHz core keeps cryptographic and UI response times short without a second processor.
Recommended
Consumer Appliances
Cost-sensitive appliance control boards use the MK21FX512VLQ12 for its balance of 120 MHz performance, generous 512 KB flash for UI frameworks and communication stacks, and integrated analog for temperature and current sensing. Four UARTs handle touch panels, Wi-Fi modules, and cloud gateways concurrently; I2C manages sensors and EEPROMs. The 144-LQFP package provides the I/O count for displays, relays, and keypad matrices in a single controller, reducing board-level component count versus multi-chip alternatives.
Recommended
Test and Measurement Equipment
Bench instruments and data loggers exploit the MK21FX512VLQ12's high-speed ADCs, precise timing peripherals, and USB OTG port for PC connectivity. The 120 MHz Cortex-M4 with FPU performs calibration math, FFT-based analysis, and trigger logic in real time, while 128 KB SRAM sustains deep sample buffering. Two SPI modules stream results to displays or external converters, and I2S supports audio-band measurement front ends. The 144-pin LQFP delivers the pin count needed for multi-channel analog front ends on one controller.
Recommended
Recommended Products Summary
Engineering reference data for MK21FX512VLQ12 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MK21FX512VLQ10 | MK21FN1M0VLQ12 | MK21DX256VLQ5 | MK21DN512VLQ5 | MK22FX512VLQ12 |
|---|---|---|---|---|---|---|
| Package | 144-LQFP (20 x 20 mm) | 144-LQFP - same | 144-LQFP - same | 144-LQFP - same | 144-LQFP - same | 144-LQFP - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core / Max Clock | Cortex-M4, 120 MHz | Cortex-M4, 100 MHz | Cortex-M4, 120 MHz | Cortex-M4, 100 MHz | Cortex-M4, 100 MHz | Cortex-M4, 120 MHz |
| Flash | 512 KB | 512 KB | 1 MB | 256 KB | 512 KB (split program/FlexNVM) | 512 KB |
| SRAM | 128 KB | 128 KB | 128 KB | 64 KB | 128 KB | 128 KB |
Key Differentiators
- Hardware encryption with tamper detection (vs MK21DX256VLQ5)
- Fastest K21 144-LQFP speed grade (vs MK21FX512VLQ10)
- Balanced memory without over-provisioning (vs MK21FN1M0VLQ12)
Design Notes
The 144-LQFP (20 x 20 mm) exposes multiple VDD/VSS pairs that must each be decoupled with 100 nF ceramic capacitors placed within 2-3 mm of the pins, plus bulk capacitance near the regulator. Follow the power connection guidelines in the K21 technical data sheet (K21P80M50SF4 Rev. 4.1): keep VDDA/VSSA on a quiet analog island with an RC or ferrite filter from the digital rail to preserve ADC accuracy. Use 0.5 mm pitch escape routing and allow at least 4 mil trace/space.
This part is NRND per the NXP product page. Before releasing a new PCB revision around the MK21FX512VLQ12, confirm supply lifetime with NXP and arrange a last-time-buy buffer, or pre-qualify a drop-in K21 family variant (e.g., MK21FX512VLQ10 in the same 144-LQFP footprint). Also note the SWD/JTAG debug muxing and EZPORT boot modes: pull the appropriate boot configuration pins correctly at reset or the device may enter bootloader instead of executing flash code.
Estimated: at 120 MHz with all peripherals active, K21-family core current is typically in the tens of mA (verify exact IDD from the datasheet power tables for your configuration). At 3.3 V and ~50 mA, dissipation is ~0.17 W; the 144-LQFP theta_JA of roughly 40-50 C/W over a standard JEDEC 4-layer board yields only ~8 C junction rise, so no heatsink is required. Ensure your board follows the datasheet-recommended thermal pad/via pattern if operating at the top of the industrial temperature range.
Compliance Information
REACH status: REACH Unaffected (per Rochester Electronics listing). HTSUS: 8542.31.0001. RoHS/lead-free status not stated in provided data - verify on NXP product page.