NXP Semiconductors MCF51AC256ACLKE

Overview

MCF51AC256ACLKE from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller with CAN interface, 256 KB flash, 32 KB SRAM, and 80-pin LQFP package operating up to 50.33 MHz at 2.7–5.5 V. It integrates dual analog comparators, 24-channel 12-bit ADC, dual FTM modules, CRC engine, and I²C/SCI/SPI peripherals - deployed in industrial motor control and automotive body electronics.

For engineers reviewing the MCF51AC256ACLKE datasheet, MCF51AC256ACLKE pinout, MCF51AC256ACLKE application, or MCF51AC256ACLKE equivalent, key selection factors include CAN 2.0A/B compliance, 80-pin LQFP thermal performance at –40°C to +85°C, ColdFire V1 ISA_C instruction set compatibility, and on-chip BDM debug support for real-time trace and breakpoint debugging.

Technical Context

The MCF51AC256ACLKE implements the ColdFire V1 core with background debug module (BDM), supporting single-wire real-time tracing via VBUS and six hardware breakpoints. Its multipurpose clock generator (MCG) combines FLL/PLL with trimmable internal reference (0.2% resolution) and supports crystal (1–16 MHz) or ceramic resonator inputs.

System-level integration includes two flexible timer modules (FTM1/FTM2) with deadtime insertion for complementary PWM, MSCAN controller with five receive buffers and programmable wakeup, and a 12-bit ADC with asynchronous clocking for low-noise operation - all accessible through 69 GPIOs including 16 Rapid GPIO pins tied directly to the 32-bit platform bus.

Key Specifications

Pinout & Package

Package: 80-pin LQFP (14 mm × 14 mm), lead-free, RoHS-compliant, thermal pad optional per Freescale packaging specification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 32-bit microcontroller applications.

Compared with MCF51JM128CLK, the MCF51AC256ACLKE provides essential CAN 2.0B support and double flash capacity; versus Kinetis K22FN512VLH12, it retains ColdFire toolchain continuity and deterministic BDM debug but trades off ARM ecosystem scalability.

Availability

MCF51AC256ACLKE is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical infusion pumps, and energy metering gateways requiring stable component supply across extended temperature ranges.

Supply support for MCF51AC256ACLKE 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 delivering secure, scalable solutions for automotive, industrial, IoT, and mobile applications.

The MCF51AC256 series belongs to NXP's ColdFire microcontroller product line, designed specifically to bridge 8-bit MCUs (e.g., S08AC128) to 32-bit performance while maintaining code compatibility and debug continuity for cost-sensitive industrial upgrades.

FAQ

What is the maximum operating frequency of the MCF51AC256ACLKE?

The MCF51AC256ACLKE operates at up to 50.33 MHz across its full 2.7–5.5 V supply range and –40°C to +85°C temperature grade. This frequency is achieved using the on-chip MCG with FLL/PLL enabled and a stable crystal or external clock source. Performance is verified per Freescale Document Number MCF51AC256 Rev.7, Section 2.11.1.

Does the MCF51AC256ACLKE support CAN FD or only classical CAN?

The MCF51AC256ACLKE implements the MSCAN module compliant with CAN 2.0A/B only - it does not support CAN FD. Its MSCAN controller handles standard and extended frames up to 8 bytes per message at bit rates up to 1 Mbps, with programmable filters and bus-off recovery. CAN FD capability was introduced in later NXP families such as S32K.

How many analog-to-digital converter channels does the MCF51AC256ACLKE have?

The MCF51AC256ACLKE features a 12-bit SAR ADC with 24 analog input channels (AD1P0–AD1P23), as confirmed in Table 1 and Section 1.3.1 of the MCF51AC256 Rev.7 datasheet. Inputs are distributed across Ports A, B, D, G, H, and J, with dedicated VREFH/VREFL references and asynchronous clocking for noise reduction.

Is the MCF51AC256ACLKE pin-compatible with other members of the MCF51AC256 family?

Yes - the MCF51AC256ACLKE shares identical 80-pin LQFP pinout with MCF51AC256AVLKE and MCF51AC256BVLKE. All three use the same mechanical outline (Figure 2, Rev.7) and pin function mapping. Differences are limited to CAN presence (A vs. B suffix) and temperature grade (C = –40°C to +85°C, V = –40°C to +105°C).

What debug interface does the MCF51AC256ACLKE provide?

The MCF51AC256ACLKE provides a single-wire Background Debug Mode (BDM) interface via the BKGD/MS pin, supporting real-time program trace, six hardware breakpoints (4 PC, 1 address pair, 1 data), and on-chip trace buffer with PC-profiling mode. This is part of the integrated ColdFire V1 core and documented in Section 1.3.1 and Figure 1 of the MCF51AC256 Rev.7 datasheet.