NXP Semiconductors MK51DX128CLK7

Overview

MK51DX128CLK7 from NXP Semiconductors (formerly Freescale) is a Kinetis K51 32-bit ARM Cortex-M4 microcontroller with DSP extension, 128 KB flash, 72 MHz max CPU frequency, and integrated analog peripherals including dual 16-bit SAR ADCs, 12-bit DAC, and TSI for touch sensing - deployed in industrial HMI, portable medical devices, and low-power sensor nodes.

For engineers reviewing the MK51DX128CLK7 datasheet, MK51DX128CLK7 pinout, MK51DX128CLK7 application, or MK51DX128CLK7 equivalent, key selection considerations include its 72 MHz Cortex-M4 core with FPU support, -40°C to +85°C temperature grade, 32-pin QFN package, USB OTG interface, and ultra-low-power stop mode current as low as 1.47 µA.

Technical Context

The MK51DX128CLK7 implements a multi-clock architecture with three independent oscillators: a 3–32 MHz main crystal oscillator, a 32 kHz RTC crystal oscillator, and an internal 1000 µs-trimmed low-power oscillator. Its MCG (Multipurpose Clock Generator) supports multiple modes including FEE (FEI → FBE → FEE) for full-speed operation and BLPE for low-power run mode.

It integrates a 16-channel DMA controller supporting up to 63 request sources, hardware CRC module, 128-bit unique chip ID, and security features including flash protection and memory isolation. The analog subsystem includes programmable gain amplifiers (x1–x64) per ADC channel, transimpedance amplifier, and three comparators each with embedded 6-bit DAC and selectable reference.

Key Specifications

Pinout & Package

Package: 32-pin QFN (5 mm × 5 mm, 0.5 mm pitch), RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MK22FN128VLH10 and STM32L476RG, the MK51DX128CLK7 uniquely combines 72 MHz real-time control, ultra-low-power stop modes, and integrated HMI peripherals - reducing system-level component count and PCB area in compact industrial and medical devices.

Availability

MK51DX128CLK7 is available at Aetrix Electronics and suitable for industrial HMI, portable medical monitors, and smart building sensor nodes requiring stable component supply across extended product lifecycles.

Supply support for MK51DX128CLK7 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 processing.

The MK51DX128CLK7 belongs to the Kinetis K51 sub-family - designed specifically for cost-sensitive, low-power industrial and consumer HMI applications requiring integrated analog, touch, display, and USB connectivity in compact packages.

FAQ

What is the maximum operating frequency of the MK51DX128CLK7?

The MK51DX128CLK7 operates at a maximum CPU frequency of 72 MHz, achieved using the MCG in FEE mode with a 32 MHz crystal and PLL multiplication. This frequency is fully supported across the -40°C to +85°C temperature range and 1.71–3.6 V supply voltage, enabling deterministic real-time execution for motor control and audio processing tasks without external clock synthesis.

Does the MK51DX128CLK7 support USB device functionality without an external transceiver?

Yes, the MK51DX128CLK7 integrates a full-speed/low-speed USB On-The-Go controller with an on-chip transceiver. It supports USB device mode (CDC, HID, MSC classes) directly via USB_DP and USB_DM pins, eliminating the need for external PHY components. The internal regulator and termination resistors are included, requiring only standard 90 Ω differential PCB routing and proper VBUS sensing.

What analog peripherals are integrated into the MK51DX128CLK7?

The MK51DX128CLK7 integrates two 16-bit SAR ADCs (each with programmable gain amplifier up to x64), a 12-bit DAC, three analog comparators (each with embedded 6-bit DAC and programmable reference), two operational amplifiers, one transimpedance amplifier, and a precision voltage reference. These peripherals enable direct sensor interface for applications such as precision temperature measurement, current sensing, and biomedical signal acquisition without external signal conditioning.

What is the lowest power consumption mode available on the MK51DX128CLK7?

The MK51DX128CLK7 achieves its lowest active-retention power state in Very-Low-Leakage Stop Mode 1 (VLLS1), drawing just 1.47 µA at 3.0 V and -40°C to 25°C ambient. In this mode, the RTC, 128-bit ID, and selected wakeup sources remain active while the core, flash, and most peripherals are powered down - ideal for battery-powered endpoints requiring decade-long operation with periodic wake events.

Is the MK51DX128CLK7 pin-compatible with other Kinetis K51 family members?

The MK51DX128CLK7 uses a 32-pin QFN package (5 mm × 5 mm), which is distinct from larger K51 variants (e.g., 48-, 64-, or 100-pin LQFP/MAPBGA). While it shares the same K51 core architecture and peripheral register map, pin compatibility is limited to other 32-pin QFN K51 parts such as MK51DN128CLK7 (no FlexMemory) - not with MK51DX256CLK7 (same package but different flash configuration) due to differing pin multiplexing for larger memory interfaces.