NXP Semiconductors MK51DX256CLK7

Overview

MK51DX256CLK7 from NXP Semiconductors (formerly Freescale) is a 32-bit ARM Cortex-M4 microcontroller with DSP extensions, 256 KB flash, 64 KB RAM, and 72 MHz max CPU frequency. It integrates dual 16-bit SAR ADCs with PGA, 12-bit DAC, USB OTG, LCD controller, TSI, and multiple low-power modes. Used in industrial HMI, portable medical devices, and smart sensor nodes requiring mixed-signal processing and battery longevity.

For engineers reviewing the MK51DX256CLK7 datasheet, MK51DX256CLK7 pinout, MK51DX256CLK7 application, or MK51DX256CLK7 equivalent, key selection considerations include its 72 MHz Cortex-M4 core, dual ADC architecture with integrated PGA, USB full-speed OTG capability, segment LCD support up to 36×8, and verified VLLS1 stop-mode current of 1.47 μA at –40 to 25°C.

Technical Context

The MK51DX256CLK7 implements the Kinetis K51 sub-family architecture with MCG clock generator supporting FEE/FBE/BLPE modes, enabling flexible clock source selection between internal RC, external crystal (3–32 MHz), and 32 kHz RTC oscillator. Its memory subsystem includes 256 KB program flash with FlexMemory partitioning and 64 KB SRAM with ECC-capable regions.

Peripherals are organized into domain-specific clock gates: system-level modules (DMA, watchdog, LPUART), analog subsystem (ADC/DAC/CMP/PGA/op-amps), timing resources (PDB, TPM, LPTMR, RTC), and communication interfaces (USB OTG, two SPI/I²C, four UART, I²S). All operate within 1.71–3.6 V supply and –40 to +85°C ambient range.

Key Specifications

Pinout & Package

Package: 80-pin LQFP (12 mm × 12 mm), lead-free, RoHS-compliant. Pin mapping follows K51 Sub-Family Data Sheet Rev. 3, Section 8.2 - pin assignments validated for MK51DX256CLK7 via official Freescale package diagram LK variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MK51DX256CLK7, KL27Z128VLH4 offers lower BOM cost and deeper sleep but sacrifices signal processing capability and HMI integration; MKE15Z128VLH7 matches clock speed and adds CAN FD yet omits the dual ADC+PGA architecture critical for precision analog acquisition.

Availability

MK51DX256CLK7 is available at Aetrix Electronics and suitable for industrial HMI, portable medical devices, and smart utility metering requiring stable component supply, long-term lifecycle assurance, and qualified automotive-grade traceability.

Supply support for MK51DX256CLK7 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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The Kinetis K51 series was designed for cost-optimized, low-power mixed-signal applications demanding rich peripheral integration - particularly targeting portable instrumentation, building automation controllers, and battery-operated human interface systems.

FAQ

What is the maximum operating frequency of the MK51DX256CLK7?

The MK51DX256CLK7 supports a maximum system and core clock frequency of 72 MHz, achieved using the MCG's FEE mode with external crystal or internal FLL. This frequency is validated across the full –40°C to +85°C temperature range and 1.71–3.6 V supply voltage, delivering over 100 DMIPS of processing performance for real-time control and signal processing tasks within the MK51DX256CLK7 architecture.

Does the MK51DX256CLK7 include USB functionality, and what type is supported?

Yes, the MK51DX256CLK7 integrates a full-/low-speed USB On-The-Go controller with an on-chip transceiver. It supports USB 2.0 compliance in both host and device roles, eliminating the need for an external PHY. The MK51DX256CLK7 USB module includes dedicated endpoints, descriptor handling, and suspend/resume logic - enabling direct connection to PC hosts, HID peripherals, or mass storage devices without additional silicon.

What analog peripherals are integrated into the MK51DX256CLK7?

The MK51DX256CLK7 integrates two independent 16-bit SAR ADCs, each with a programmable gain amplifier (PGA) supporting gains from ×1 to ×64; a 12-bit voltage-output DAC; three analog comparators with integrated 6-bit DAC references; two operational amplifiers; one transimpedance amplifier; and a precision voltage reference. These resources enable high-fidelity sensor signal conditioning, closed-loop actuator control, and battery monitoring directly within the MK51DX256CLK7 die.

What low-power modes does the MK51DX256CLK7 support, and what is the lowest achievable current draw?

The MK51DX256CLK7 supports seven low-power modes including VLPR, VLPW, LLS, STOP, and three VLLS variants. In VLLS1 mode, it achieves 1.47 μA typical current draw at –40°C to +25°C and 3.0 V supply; in VLLS3 mode, it draws 1.9 μA under identical conditions. These modes retain RAM, select registers, and RTC operation - making the MK51DX256CLK7 suitable for applications requiring rapid wake-up from ultra-low quiescent current states.

Is the MK51DX256CLK7 pin-compatible with other Kinetis K51 family members?

No - the MK51DX256CLK7 uses the 80-pin LQFP (LK) package, while other K51 variants use different packages (e.g., 64-pin LQFP, 100-pin LQFP, or MAPBGA). Pin assignments are specific to the LK package per Section 8.2 of the K51 Sub-Family Data Sheet. Although functional peripherals overlap across the family, direct PCB replacement requires matching package size, pin count, and validated signal mapping - which is not guaranteed between MK51DX256CLK7 and other K51 orderables.