NXP Semiconductors MK51DX256CLL7

Overview

MK51DX256CLL7 from NXP Semiconductors (formerly Freescale) is a Kinetis K51-series ARM Cortex-M4 microcontroller with DSP extension, 256 KB flash, 128 KB RAM, and 72 MHz max CPU frequency. It integrates dual 16-bit SAR ADCs with PGA, 12-bit DAC, USB OTG, five UARTs, two I²C, two SPI, I²S, RTC, and segment LCD controller. Designed for low-power industrial HMI and sensor fusion applications requiring analog-rich signal acquisition and real-time control.

For engineers reviewing the MK51DX256CLL7 datasheet, MK51DX256CLL7 pinout, MK51DX256CLL7 application, or MK51DX256CLL7 equivalent, key selection considerations include its 100-pin LQFP-100 package, –40°C to +85°C temperature grade, 1.71–3.6 V supply range, integrated touch-sensing interface (TSI), and support for multiple low-power stop modes down to 1.47 µA (VLLS1).

Technical Context

The MK51DX256CLL7 implements a 32-bit ARM Cortex-M4 core with DSP instructions and no FPU. Its clock system includes a multi-purpose clock generator (MCG) supporting FEI/FBI/FEE/FBE/BLPE modes, 3–32 MHz main crystal oscillator, and 32 kHz RTC oscillator. Memory subsystem comprises 256 KB on-chip flash with FlexMemory partitioning capability and 128 KB SRAM with ECC support.

Peripherals are organized into domain-specific clock gates: analog modules (ADC, DAC, CMP, op-amps, TIA) operate from VDDA/VSSA; USB uses dedicated 3.3 V regulator input; and low-leakage wakeup unit enables sub-µA wake-from-VLLS transitions. The device supports JTAG/SWD debug via dedicated pins and includes hardware CRC, 128-bit unique ID, and programmable security features.

Key Specifications

Pinout & Package

Package: 100-pin LQFP (14 mm × 14 mm), thermally enhanced with exposed pad (LL suffix per part numbering convention). Pinout conforms to K51 Sub-Family Data Sheet Rev. 3, Section 8.2 - pin assignments validated for MK51DX256CLL7 across all signal multiplexing options.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MK51DX256CLL7, MK51DN256CLL7 removes FlexMemory but reduces cost for fixed-parameter applications, while MK52DN512CLL7 adds Ethernet and flash headroom at identical pinout - enabling scalable product families with minimal layout changes.

Availability

MK51DX256CLL7 is available at Aetrix Electronics and suitable for industrial HMI panels, portable medical sensor hubs, and smart energy meter interfaces requiring stable component supply across extended product lifecycles.

Supply support for MK51DX256CLL7 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications. Formerly Freescale Semiconductor, it acquired the Kinetis portfolio in 2015.

The Kinetis K51 series targets cost-sensitive, analog-intensive embedded systems requiring robust low-power operation and human-machine interface integration - specifically optimized for industrial control panels and portable instrumentation.

FAQ

What is the maximum operating frequency of the MK51DX256CLL7?

The MK51DX256CLL7 operates at a maximum CPU frequency of 72 MHz, achieved using the MCG in FEE mode with an external 32 MHz crystal and PLL multiplication. This frequency is sustained across the full –40°C to +85°C ambient temperature range and 1.71–3.6 V supply voltage, as verified in the K51 Sub-Family Data Sheet Rev. 3, Table 8.

Does the MK51DX256CLL7 support USB device and host functionality simultaneously?

Yes, the MK51DX256CLL7 integrates a USB On-The-Go (OTG) controller that supports both full-speed (12 Mbps) and low-speed (1.5 Mbps) operation in device, host, or OTG mode. Its on-chip transceiver eliminates external PHY components, and the USB_VREG input allows direct connection to 5 V USB power when configured as host - confirmed in Section 6.8.1 of the K51 Sub-Family Data Sheet.

How much SRAM does the MK51DX256CLL7 include, and is it ECC-protected?

The MK51DX256CLL7 includes 128 KB of on-chip SRAM, with error-correcting code (ECC) protection enabled by default for all SRAM accesses. ECC coverage applies to both read and write operations, detecting and correcting single-bit errors and detecting double-bit errors - documented in Chapter 6.4.1 of the K51 Sub-Family Data Sheet Rev. 3.

What low-power modes are available on the MK51DX256CLL7, and what is the lowest current draw?

The MK51DX256CLL7 supports seven low-power modes: RUN, WAIT, VLPR, STOP, VLPS, LLS, and three VLLS variants. The lowest active current is 1.47 µA in VLLS1 mode at 3.0 V and –40°C to 25°C ambient, retaining RAM, RTC, and selected GPIO wake sources - specified in Table 6 of the K51 Sub-Family Data Sheet Rev. 3.

Can the MK51DX256CLL7 drive a segment LCD directly, and what is the maximum configuration?

Yes, the MK51DX256CLL7 includes a dedicated segment LCD controller supporting up to 36 frontplane × 8 backplane or 40 frontplane × 4 backplane configurations, depending on enabled peripherals and pin multiplexing. This capability is implemented in hardware with built-in charge pump and contrast control registers - detailed in Section 6.9.2 of the K51 Sub-Family Data Sheet Rev. 3.