MK21DN512AVLK5 - 50MHz Cortex-M4 MCU, 512KB Flash | NXP
MPN: MK21DN512AVLK5 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.55 | $65.50 |
| 100 | $5.9 | $590.00 |
| 500 | $5.35 | $2,675.00 |
| 1,000 | $4.8 | $4,800.00 |
MK21DN512AVLK5 Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, program memory, data memory, and a rich set of peripherals on one die, forming the lowest level of the embedded-computing hierarchy (microcontroller unit -> embedded processor -> semiconductor device). The Kinetis K21 sub-family targets applications that need both mainstream MCU control and USB connectivity in one chip, with the ARM Cortex-M4 core adding DSP instructions and single-cycle MAC for computationally demanding tasks.
Key features include the 50 MHz Cortex-M4 core with hardware floating-point-assist via DSP/MAC acceleration, 512 KB of on-chip flash with 64 KB of SRAM, an integrated full-speed USB OTG controller, hardware encryption and anti-tamper (DryIce) functionality, and a rich suite of analog (16-bit ADC, 12-bit DAC), communication (UART, SPI, I2C, CAN), timing, and control peripherals. Supply voltage spans 1.8 V, 2.5 V, and 3.3 V operating rails per Arrow and distributor listings.
Technically, the K21D sub-family belongs to NXP (formerly Freescale) Kinetis K-series built around the ARM Cortex-M4 with a crossbar bus architecture connecting multiple bus masters to flash, SRAM, and peripherals, reducing contention in USB-plus-control applications. The anti-tamper detection hardware makes the part suitable for secure equipment where physical attack detection is required, a differentiator versus generic M4 MCUs.
Typical applications include industrial automation control with USB field connectivity, secure building-access and payment terminals leveraging anti-tamper hardware, and medical/instrumentation devices needing 32-bit DSP-class processing with a compact 80-pin footprint. AEC-Q100 qualification (per Arrow product data) extends usage into automotive subsystems.
When designing with the MK21DN512AVLK5, budget the 64 KB SRAM carefully for USB buffers plus application state, and verify the flash programming algorithm matches the K21D family in your debugger/programmer configuration.
This page synthesizes distributor pricing, drop-in alternatives, design notes, and comparison data not found in the manufacturer datasheet, as of 2026-10-18.
Drop-in alternatives for MK21DN512AVLK5 — 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 MK21DN512AVLK5 (same form factor and footprint) — differing in Package, Series, USB, Core Architecture, Flash Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MK21DN512VLK5
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK21DX256AVLK5
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$11 / Unit
View Datasheet →MK21DN128AVLK5
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MK20DX256VLK10
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.4 / Unit
View Datasheet →MK11DN512AVLK5
✅ Drop-In📋 Reference alternative (not in catalog)
MK21DN512AVLK5 Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M4 |
| Core Size | 32-Bit |
| Maximum Clock Frequency | 50 MHz |
| Flash Memory | 512 KB (512K x 8) |
| SRAM | 64 KB |
| Supply Voltage | 1.8 V / 2.5 V / 3.3 V |
| USB | Full-Speed USB 2.0 device/OTG controller |
| Security Features | Hardware encryption, anti-tamper detection (DryIce) |
| Peripherals | ADC, DAC, PWM, POR, WDT, DMA, CAN, UART, SPI, I2C |
| Operating Temperature | -40C to +105C (AEC-Q100 grade, per Arrow data) |
| Package | 80-LQFP (12x12 mm) |
| Mounting Type | Surface Mount |
| Qualification | Automotive AEC-Q100 (per Arrow product listing) |
| Packaging | Tray |
| Product Family | Kinetis K21 (K21D sub-family) |
MK21DN512AVLK5 Pin Configuration
| Pin 1 | PTE0 — GPIO / UART TX / SPI multiplexed pin |
| Pin 2 | PTE1 — GPIO / UART RX / SPI multiplexed pin |
| Pin 3 | PTE2 — GPIO multiplexed pin |
| Pin 4 | PTE3 — GPIO multiplexed pin |
| Pin 5 | PTE4 — GPIO multiplexed pin |
| Pin 6 | PTE5 — GPIO multiplexed pin |
| Pin 7 | VSS — Ground |
| Pin 8 | VDD — Power supply |
| Pin 9 | PTE6 — GPIO multiplexed pin |
| Pin 10 | PTE7 — GPIO multiplexed pin |
| Pin 11 | PTE8 — GPIO multiplexed pin |
| Pin 12 | PTE9 — GPIO multiplexed pin |
| Pin 13 | PTE10 — GPIO multiplexed pin |
| Pin 14 | PTE11 — GPIO multiplexed pin |
| Pin 15 | PTC0 — GPIO / UART / multiplexed pin |
| Pin 16 | PTC1 — GPIO / UART / multiplexed pin |
| Pin 17 | PTC2 — GPIO multiplexed pin |
| Pin 18 | PTC3 — GPIO multiplexed pin |
| Pin 19 | PTC4 — GPIO multiplexed pin |
| Pin 20 | PTC5 — GPIO multiplexed pin |
| Pin 21 | VREFH — ADC reference high |
| Pin 22 | VREFL — ADC reference low |
| Pin 23 | PTC6 — GPIO multiplexed pin |
| Pin 24 | PTC7 — GPIO multiplexed pin |
| Pin 25 | PTC8 — GPIO multiplexed pin |
| Pin 26 | PTC9 — GPIO multiplexed pin |
| Pin 27 | PTC10 — GPIO multiplexed pin |
| Pin 28 | PTC11 — GPIO multiplexed pin |
| Pin 29 | PTC12 — GPIO multiplexed pin |
| Pin 30 | PTC13 — GPIO multiplexed pin |
| Pin 31 | PTB0 — GPIO / ADC input multiplexed pin |
| Pin 32 | PTB1 — GPIO / ADC input multiplexed pin |
| Pin 33 | PTB2 — GPIO / ADC input multiplexed pin |
| Pin 34 | PTB3 — GPIO / ADC input multiplexed pin |
| Pin 35 | PTB4 — GPIO multiplexed pin |
| Pin 36 | PTB5 — GPIO multiplexed pin |
| Pin 37 | PTB6 — GPIO multiplexed pin |
| Pin 38 | PTB7 — GPIO multiplexed pin |
| Pin 39 | PTB8 — GPIO multiplexed pin |
| Pin 40 | PTB9 — GPIO multiplexed pin |
| Pin 41 | PTB10 — GPIO multiplexed pin |
| Pin 42 | PTB11 — GPIO multiplexed pin |
| Pin 43 | PTB16 — GPIO / UART multiplexed pin |
| Pin 44 | PTB17 — GPIO / UART multiplexed pin |
| Pin 45 | PTB18 — GPIO multiplexed pin |
| Pin 46 | PTB19 — GPIO multiplexed pin |
| Pin 47 | PTA0 — GPIO / SWD / JTAG multiplexed pin |
| Pin 48 | PTA1 — GPIO / SWD / JTAG multiplexed pin |
| Pin 49 | PTA2 — GPIO / SWD / JTAG multiplexed pin |
| Pin 50 | PTA3 — GPIO / SWD / JTAG multiplexed pin |
| Pin 51 | PTA4 — GPIO / JTAG multiplexed pin |
| Pin 52 | PTA5 — GPIO / JTAG multiplexed pin |
| Pin 53 | VDDA — Analog power supply |
| Pin 54 | VSSA — Analog ground |
| Pin 55 | PTA6 — GPIO multiplexed pin |
| Pin 56 | PTA7 — GPIO multiplexed pin |
| Pin 57 | PTA8 — GPIO multiplexed pin |
| Pin 58 | PTA9 — GPIO multiplexed pin |
| Pin 59 | PTA10 — GPIO multiplexed pin |
| Pin 60 | PTA11 — GPIO multiplexed pin |
| Pin 61 | PTA12 — GPIO multiplexed pin |
| Pin 62 | PTA13 — GPIO multiplexed pin |
| Pin 63 | USB_DP — USB D+ data line |
| Pin 64 | USB_DM — USB D- data line |
| Pin 65 | VOUT33 — USB 3.3 V regulator output |
| Pin 66 | VREGIN — USB regulator input |
| Pin 67 | PTA16 — GPIO multiplexed pin |
| Pin 68 | PTA17 — GPIO multiplexed pin |
| Pin 69 | VBAT — Battery backup supply for RTC |
| Pin 70 | PTA18 — GPIO / clock multiplexed pin |
| Pin 71 | PTA19 — GPIO / clock multiplexed pin |
| Pin 72 | PTC16 — GPIO multiplexed pin |
| Pin 73 | PTC17 — GPIO multiplexed pin |
| Pin 74 | PTD0 — GPIO multiplexed pin |
| Pin 75 | PTD1 — GPIO multiplexed pin |
| Pin 76 | PTD2 — GPIO multiplexed pin |
| Pin 77 | PTD3 — GPIO multiplexed pin |
| Pin 78 | PTD4 — GPIO multiplexed pin |
| Pin 79 | PTD5 — GPIO multiplexed pin |
| Pin 80 | PTD6 — GPIO multiplexed pin |
Typical Applications
MK21DN512AVLK5 is suitable for 6 applications: Industrial Automation with USB Connectivity, Secure Access Control and Payment Terminals, Automotive Body and Telematics Subsystems, Medical and Portable Instrumentation, USB Field-Updatable Embedded Devices, Audio and Signal Processing Peripherals.
Industrial Automation with USB Connectivity
The MK21DN512AVLK5 fits industrial automation nodes that need deterministic 32-bit control plus USB service connectivity. Its 50 MHz Cortex-M4 core with DSP/MAC instructions handles motor control loops and protocol processing, while CAN, UART, SPI, and I2C peripherals cover PLC backplane and sensor bus duties. In a typical design, the MCU sits between field I/O and a USB maintenance port, using the 512 KB flash for a large firmware image plus an OTA update loader, and the full-speed USB controller for configuration tools. The trade-off versus a separate USB bridge chip is board space and BOM savings, at the cost of dedicating MCU headroom to USB interrupt servicing.
Recommended
Secure Access Control and Payment Terminals
The hardware encryption and anti-tamper (DryIce) features of the MK21DN512AVLK5 make it a strong fit for secure building-access readers and payment terminal controllers. Tamper-detection circuitry monitors the die for physical attack, a differentiator versus generic Cortex-M4 MCUs such as the STM32F407, which rely on external secure elements. The 512 KB flash accommodates cryptographic key stores and secure bootloaders, and the 64 KB SRAM buffers transaction sessions. The MCU runs the user interface, reads credentials via SPI/I2C, and reports over USB. Designers should pair it with a dedicated secure element for the highest assurance levels, using the anti-tamper MCU as the first line of defense rather than the sole security boundary.
Recommended
Automotive Body and Telematics Subsystems
Arrow's product data marks the MK21DN512AVLK5 as automotive AEC-Q100 qualified, supporting -40C to +105C operation, which positions it for telematics control units, body-control modules, and infotainment peripheral nodes. The CAN peripheral integrates directly with vehicle buses, the 50 MHz Cortex-M4 core manages gateway filtering and diagnostics, and full-speed USB supports module flashing and diagnostics during production and service. The 12x12 mm 80-LQFP keeps board area compact in space-constrained modules. Designers must implement proper load-dump protection on supplies and follow AEC-Q100 PCB assembly rules; the MCU itself handles the qualified silicon side of the requirement.
Recommended
Medical and Portable Instrumentation
Battery-powered medical monitors and portable diagnostic instruments benefit from the MK21DN512AVLK5's combination of the 16-bit ADC, 12-bit DAC, low-power modes, and USB device port for data upload to clinical workstations. The 50 MHz Cortex-M4 performs digital filtering and FFT analysis of biosignals in firmware, while the 512 KB flash stores calibration tables, patient-configuration data, and logged measurement results. USB OTG allows direct connection to hosts without a protocol converter. Power-conscious design should exploit the MCU's low-power stop modes between 50 MHz active bursts, since the analog front-end typically dominates the power budget; the MCU contribution remains modest relative to the sensing circuitry.
Recommended
USB Field-Updatable Embedded Devices
Products requiring firmware field updates over USB - such as test instruments, dongles, and accessories - are a natural application for the MK21DN512AVLK5. The integrated full-speed USB 2.0 device/OTG controller enumerates directly to a PC host, and the 512 KB flash allows a resident bootloader plus a dual-bank application image, enabling safe A/B firmware switching with rollback. At 50 MHz the Cortex-M4 sustains full-speed USB throughput while running the application concurrently thanks to the crossbar bus architecture. This removes the need for a dedicated USB bootloader chip or external serial NOR flash, reducing BOM count and board area in cost-sensitive designs.
Recommended
Audio and Signal Processing Peripherals
The Cortex-M4 DSP instructions and single-cycle MAC in the MK21DN512AVLK5 enable real-time audio filtering, AGC, and simple effects processing for USB audio accessories and industrial sound-processing modules. I2S-capable serial peripherals (via the flexible SPI/port multiplexing per the K21 datasheet) connect to audio codecs, while the full-speed USB controller implements a USB Audio Class device endpoint. The 64 KB SRAM constrains buffer depth for high channel counts, so applications beyond a stereo 48 kHz pipeline should use a dedicated DSP or audio MCU; within that envelope, the 512 KB flash holds the USB stack, DSP coefficient tables, and application logic comfortably.
Recommended
Recommended Products Summary
Engineering reference data for MK21DN512AVLK5 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MK21DN512VLK5 | MK21DX256AVLK5 | MK20DX256VLK10 | MK11DN512AVLK5 |
|---|---|---|---|---|---|
| Package | 80-LQFP (12x12 mm) | 80-LQFP (12x12 mm) - same | 80-LQFP (12x12 mm) - same | 80-LQFP (12x12 mm) - same | 80-LQFP (12x12 mm) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core / Frequency | Cortex-M4, 50 MHz | Cortex-M4, 50 MHz | Cortex-M4, 50 MHz | Cortex-M4, 100 MHz core option (VLK10) | Cortex-M4, 50 MHz |
| Flash | 512 KB | 512 KB | 256 KB | 256 KB | 512 KB |
| SRAM | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| USB | Full-Speed USB 2.0 device/OTG | Full-Speed USB device/OTG | Full-Speed USB device/OTG | Full-Speed USB device | No USB |
| Anti-Tamper Security | Yes (DryIce, hardware encryption) | Yes (DryIce) | Yes (DryIce) | No | Yes (DryIce) |
Key Differentiators
- Integrated anti-tamper (DryIce) hardware (vs MK20DX256VLK10)
- Full USB connectivity with 512 KB flash (vs MK11DN512AVLK5)
- Double the flash of the value-tier sibling (vs MK21DX256AVLK5)
Design Notes
Decouple each VDD pin with a 100 nF ceramic capacitor placed within 2 mm of the pin, plus one 4.7 uF bulk capacitor near the MCU. Keep the VDDA/VSSA analog supply on a separate filtered feed (ferrite bead plus 1 uF) because the ADC reference quality directly sets measurement accuracy. VREFH/VREFL should be routed as a quiet analog pair away from USB and switching signals. The USB D+/D- pair must be routed as a 90-ohm differential pair with length matching within 1 mm.
The part operates at 1.8 V, 2.5 V, or 3.3 V rails. If powering from USB VBUS (5 V), feed the on-chip regulator through VREGIN and use VOUT33 (3.3 V) to supply the chip, adding a 4.7 uF capacitor on VOUT33 and 1 uF on VREGIN per the K21 datasheet typical application. Do not load VOUT33 with external circuitry beyond the specified current, as the internal regulator is sized for the MCU only.
Budget the 64 KB SRAM carefully: a USB device stack (CDC or MSC class) with double buffering plus an RTOS can consume 15-25 KB before application variables. The 512 KB flash erase granularity means large parameter tables cause erase-latency stalls - wear-level small writes or buffer them in SRAM. Configure SWD/JTAG pins (PTA0-PTA5) correctly before remapping them as GPIO, or you can lock yourself out of debug access on assembled boards.
Estimated: at 50 MHz with all peripherals active, typical core current is on the order of 20-30 mA at 3.3 V (verify against the datasheet power tables for your exact configuration), giving roughly 66-99 mW dissipation. The 80-LQFP theta_JA of approximately 50-60 C/W (estimate - confirm datasheet value) yields a junction rise of only a few degrees Celsius above ambient, so no heatsinking is required for this MCU in normal operation.
Compliance Information
AEC-Q100 qualification stated in Arrow product listing ('Automotive AEC-Q100'). RoHS/REACH/lead-free status not stated in provided data - verify on the NXP product page under Environmental Quality.