NXP Semiconductors MCF51AC256BVLKE

Overview

MCF51AC256BVLKE from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller without CAN interface, housed in an 80-pin LQFP package (14 mm × 14 mm), operating up to 50.33 MHz at 2.7–5.5 V. It integrates 256 KB flash, 32 KB SRAM, a 12-bit 24-channel ADC, dual analog comparators, two FTM modules (6+6 channels), and SPI/I²C/SCI peripherals - deployed in industrial motor control and smart sensor nodes requiring deterministic real-time response.

For engineers reviewing the MCF51AC256BVLKE datasheet, MCF51AC256BVLKE pinout, MCF51AC256BVLKE application, or MCF51AC256BVLKE equivalent, key selection criteria include its CAN-free configuration, 80-pin LQFP footprint with 69 GPIOs, V1 ColdFire ISA_C instruction set compliance, background debug module (BDM) support, and operation across –40°C to +105°C industrial temperature range.

Technical Context

The MCF51AC256BVLKE implements the ColdFire V1 core with instruction set revision C (ISA_C), delivering 0.76 DMIPS/MHz when executing from flash and 0.94 DMIPS/MHz from SRAM. Its multipurpose clock generator (MCG) supports FLL/PLL-based frequency multiplication using external crystals (1–16 MHz) or internal reference, enabling precise system clock derivation.

It features two independent flexible timer modules (FTM1 and FTM2), each supporting input capture, output compare, edge- or center-aligned PWM, deadtime insertion for complementary outputs, and hardware-triggered ADC conversions. The absence of CAN peripheral distinguishes it from the 'A' variant while retaining full TPM3, CRC, KBI, and RGPIO functionality.

Key Specifications

Pinout & Package

Package: 80-pin LQFP, 14 mm × 14 mm, 0.5 mm pitch, RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCF51AC256AVLKE, the MCF51AC256BVLKE removes CAN hardware to reduce gate count and power, making it optimal for standalone control tasks; versus Kinetis K22FN512VLH12, it offers proven ColdFire ecosystem compatibility but lower peak throughput and no USB.

Availability

MCF51AC256BVLKE is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, PLC I/O modules, and automotive body control units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MCF51AC256BVLKE 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Freescale's microcontroller heritage.

The MCF51AC256 series belongs to NXP's ColdFire microcontroller product line, designed specifically for cost-sensitive, high-reliability embedded control applications transitioning from 8-bit MCUs like the MC9S08AC128 - emphasizing integrated analog, deterministic timing, and industrial-grade robustness.

FAQ

Does the MCF51AC256BVLKE support CAN bus communication?

No, the MCF51AC256BVLKE does not include a CAN controller. The 'B' in the part number explicitly denotes the CAN-disabled variant. Pins PTA0 (TxCAN) and PTA1 (RxCAN) are repurposed as general-purpose I/O in this version. For CAN-enabled operation, select the MCF51AC256AVLKE instead. All other peripherals - including FTM, ADC, SPI, and I²C - remain functionally identical between the two variants.

What is the maximum clock frequency and voltage range for the MCF51AC256BVLKE?

The MCF51AC256BVLKE operates at up to 50.33 MHz across a supply voltage range of 2.7 V to 5.5 V. This frequency is achievable under full industrial temperature conditions (–40°C to +105°C) when powered within specification. The multipurpose clock generator (MCG) supports multiple modes - including FEI (internal FLL), FBE (external crystal with FLL), and PBE (PLL-enabled) - allowing flexible clock source selection without external PLL components.

How many analog-to-digital converter (ADC) channels does the MCF51AC256BVLKE have, and what is its resolution?

The MCF51AC256BVLKE features a single 12-bit successive-approximation ADC with up to 24 analog input channels (AD1P0–AD1P23). Conversion results can be formatted as right-justified 12-, 10-, or 8-bit values. The ADC supports single-shot and continuous conversion modes, hardware triggering from FTM modules, and automatic comparison against programmable thresholds with interrupt generation - ideal for real-time sensor monitoring in motor control and environmental sensing.

What debug interface does the MCF51AC256BVLKE provide, and is JTAG supported?

The MCF51AC256BVLKE uses a single-wire Background Debug Mode (BDM) interface via the BKGD/MS pin. It does not support standard JTAG. BDM provides full in-circuit debugging capabilities including halt/resume, register inspection, memory read/write, and up to six hardware breakpoints (four PC, one address pair, one data). Real-time trace is enabled via the debug visibility bus (VBUS), supporting continuous or PC-profiling modes without halting program execution.

Is the MCF51AC256BVLKE pin-compatible with other members of the MCF51AC256 family?

Yes, the MCF51AC256BVLKE is pin-compatible with all 80-pin LQFP variants in the MCF51AC256 family, including MCF51AC256AVLKE and MCF51AC128xVLKE. Pin assignments, electrical characteristics, and package dimensions (14 mm × 14 mm, 0.5 mm pitch) are identical. Functional differences - such as CAN presence, flash size, or RAM configuration - do not affect physical layout, enabling hardware reuse across firmware variants during design iteration or qualification.