NXP Semiconductors MCF51AC128ACPUE

Overview

MCF51AC128ACPUE from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller with CAN interface, 128 KB flash, 32 KB SRAM, and 64-pin LQFP package operating up to 50.33 MHz. It integrates dual analog comparators, 24-channel 12-bit ADC, two FTM modules, SCI/SCI2, SPI1/SPI2, IIC, and CRC engine - deployed in industrial motor control, automotive body electronics, and embedded gateway applications.

For engineers reviewing the MCF51AC128ACPUE datasheet, MCF51AC128ACPUE pinout, MCF51AC128ACPUE application, or MCF51AC128ACPUE equivalent, key selection criteria include CAN 2.0A/B compliance at up to 1 Mbps, 64-pin LQFP thermal performance (–40°C to +85°C), on-chip BDM debug support, and compatibility with MC9S08AC128 migration paths.

Technical Context

The MCF51AC128ACPUE implements the ColdFire V1 core with ISA_C instruction set, delivering 0.76 DMIPS/MHz when executing from flash and supporting background debug via single-wire BDM interface. Its MCG includes FLL/PLL clock synthesis with trimmable internal reference (0.2% resolution), external crystal oscillator (1–16 MHz), and LPO for COP/RTI.

Peripherals are tightly coupled to the local bus: RGPIO provides CPU-clock-speed I/O toggling; FTM1/FTM2 offer 6- and 4-channel PWM with deadtime insertion and ADC hardware triggering; MSCAN supports five receive buffers with FIFO, three prioritized transmit buffers, and programmable wakeup filtering.

Key Specifications

Pinout & Package

64-pin LQFP (10 mm × 10 mm, 0.5 mm pitch), RoHS-compliant, with exposed thermal pad. Pin functions validated per Figure 3 (64-Pin QFP/LQFP) in MCF51AC256 Rev.7 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCF51AC128AVPUE, the MCF51AC128ACPUE trades extended temperature rating for lower cost and same functional capability in milder environments; versus S9KEAZ128AMLH, it delivers superior deterministic I/O timing and legacy peripheral compatibility at the expense of ARM toolchain adoption.

Availability

MCF51AC128ACPUE is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, and embedded gateway applications requiring stable component supply, long-term lifecycle support, and verified CAN 2.0A/B interoperability.

Supply support for MCF51AC128ACPUE 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 acquired Freescale in 2015 and maintains the ColdFire portfolio for legacy industrial and automotive designs requiring deterministic real-time performance and long product lifecycles.

The MCF51AC series targets cost-sensitive 32-bit upgrades from 8-bit MCUs (e.g., MC9S08AC128), emphasizing integrated analog, CAN, and low-power operation for body electronics and motor control.

FAQ

What is the maximum operating frequency of the MCF51AC128ACPUE?

The MCF51AC128ACPUE operates at up to 50.33 MHz across its full voltage range (2.7 V to 5.5 V). This frequency is achievable using the MCG's PLL mode with an external 8 MHz crystal, enabling precise CAN bit timing at 1 Mbps and high-resolution PWM generation for motor control applications. The ColdFire V1 core delivers 0.76 DMIPS/MHz when running code from flash memory.

Does the MCF51AC128ACPUE support hardware debugging?

Yes, the MCF51AC128ACPUE includes a single-wire Background Debug Module (BDM) accessible via the BKGD/MS pin. It supports real-time debugging with six hardware breakpoints (four PC, one address pair, one data), on-chip trace buffer, and debug visibility bus (VBUS) for program flow analysis - all without requiring additional JTAG pins or external debug probes beyond standard BDM interfaces.

How many analog-to-digital converter channels does the MCF51AC128ACPUE have?

The MCF51AC128ACPUE features a 24-channel, 12-bit successive approximation register (SAR) ADC. Channels are mapped across Ports A, B, D, G, and H (e.g., AD1P0–AD1P23), supporting configurable resolution (12/10/8-bit), right-justified output, and hardware triggering from FTM modules - essential for synchronized current sensing in motor control systems.

Is the MCF51AC128ACPUE pin-compatible with other members of the MCF51AC family?

The MCF51AC128ACPUE shares the same 64-pin LQFP package and pinout as MCF51AC128AVPUE and MCF51AC128CVPUE, differing only in temperature grade and CAN enablement. However, it is not pin-compatible with 80-pin or 44-pin variants (e.g., MCF51AC128ACLKE or MCF51AC128CCFGE) due to differing pin counts and signal allocations per Table 4 in the datasheet.

What power supply requirements does the MCF51AC128ACPUE have?

The MCF51AC128ACPUE requires a 2.7 V to 5.5 V supply on VDD, with separate analog supplies VDDA and VSSA for the ADC and comparators. Decoupling capacitors (0.1 µF ceramic + 4.7 µF tantalum) are mandatory per datasheet Section 2.5. The device draws 25 mA typical in run mode at 50 MHz and less than 10 µA in stop3 mode - enabling energy-efficient operation in battery-powered data loggers.