NXP Semiconductors MCF51EM128CLK

Overview

MCF51EM128CLK from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 RISC microcontroller in an 80-pin LQFP package, operating up to 50.33 MHz at 2.5–3.6 V and 20 MHz at 1.8–3.6 V. It integrates 128 KB flash, 16 KB RAM, ultra-low-power IRTC with calendar, 4× ADC16 modules (12 single-ended channels), and LCD driver supporting up to 288 segments. It targets battery-powered industrial HMI and metering applications requiring robust real-time control and low-power operation.

For engineers reviewing the MCF51EM128CLK datasheet, MCF51EM128CLK pinout, MCF51EM128CLK application, or MCF51EM128CLK equivalent, this page delivers verified specifications, validated 80-pin LQFP terminal mapping, confirmed low-power run/stop mode behavior, and two documented alternative parts for design continuity in embedded metering and portable instrumentation.

Technical Context

The MCF51EM128CLK implements the ColdFire V1 core (ISA_C + MAC unit), executing 32-bit instructions with hardware multiply-accumulate optimized for 16×16±32 operations. Its internal clock source (ICS) uses three frequency-locked loops (FLLs) to generate CPU clocks from internal RC or external crystals (XOSC1: 32.768 kHz for IRTC; XOSC2: primary system reference).

Peripherals are partitioned across independent power domains: the IRTC operates from VBAT with tamper detection and battery monitoring output to ADC, while the LCD controller supports blink functionality and contrast trimming via internal charge pump and programmable voltage reference. The PDB schedules ADC conversions with 8 trigger outputs (2 per ADC module), enabling deterministic sensor sampling sequences in stop3 mode.

Key Specifications

Pinout & Package

80-pin LQFP (14 mm × 14 mm), RoHS-compliant, thermal pad exposed on underside. Pins not present on 80-pin variant (e.g., PTE0–PTE3, PTE5–PTE6, LCD16–LCD20, DADP0/DADM0/AD4, DADP3/DADM3/AD7) are automatically disabled in software; no user configuration required.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCF51EM128CLK, MCF51EM128CLL offers expanded I/O and ADC resources in a larger package, while KE02Z64VQH2 provides ARM compatibility at the expense of integrated LCD, calendar RTC, and ultra-low-power stop mode performance.

Availability

MCF51EM128CLK is available at Aetrix Electronics and suitable for smart utility metering, portable medical instrumentation, industrial HMI panels, and asset tracking beacons requiring stable component supply, long-term lifecycle support, and verified low-power performance.

Supply support for MCF51EM128CLK 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 continues development of the ColdFire family for industrial and automotive applications requiring deterministic real-time performance and low-power reliability.

The MCF51EM128CLK belongs to the ColdFire EM series, designed specifically for ultra-low-power, highly integrated embedded systems in metering, portable instrumentation, and human-machine interfaces where on-chip LCD, calendar RTC, and robust flash update are critical.

FAQ

What is the maximum CPU frequency supported by the MCF51EM128CLK under 1.8 V operation?

The MCF51EM128CLK supports up to 20 MHz CPU frequency when operating across the 1.8 V to 3.6 V supply range, as specified in the electrical characteristics section of the Rev.3 datasheet. This frequency is guaranteed over the full –40 °C to +85 °C temperature range and enables deterministic real-time response in battery-powered applications without exceeding power budgets. The MCF51EM128CLK achieves this using its internal clock source (ICS) with frequency-locked-loop (FLL) stabilization.

Does the MCF51EM128CLK include an integrated LCD driver, and what is its segment capacity?

Yes, the MCF51EM128CLK includes a fully integrated LCD controller supporting up to 288 segments (8 × 36) or 160 segments (4 × 40), as confirmed in the device comparison table and functional units description. The 80-pin LQFP variant provides 37 LCD segments (LCD0–LCD36), with flexible front-plane/backplane assignments and internal charge pump for contrast control. This eliminates the need for external LCD driver ICs in compact HMI designs.

How many analog-to-digital converter (ADC) input channels does the MCF51EM128CLK support?

The MCF51EM128CLK integrates four ADC16 modules with a total of 12 single-ended analog input channels, as explicitly stated in Table 1 (Device Comparison) of the datasheet. This is two fewer than the 100-pin MCF51EM128CLL variant (16 channels) due to pin count limitations. All ADC modules support 16-bit resolution, range compare, and operation in stop3 mode, making them suitable for precision sensor interfacing in metering applications.

What power-saving modes are available on the MCF51EM128CLK, and what is the lowest current draw?

The MCF51EM128CLK supports multiple low-power modes including stop3, low-power run, low-power wait, and reduced-power wait. Its lowest operational current is less than 1.3 μA in battery mode with MCU supply off-verified in the "Power-saving modes" section of the datasheet. This ultra-low quiescent current is achieved through independent power domains for the IRTC and selective peripheral clock gating, enabling decade-long battery life in utility meters and remote sensors.

Is the MCF51EM128CLK pin-compatible with any other members of the ColdFire EM series?

No, the MCF51EM128CLK is not pin-compatible with the 100-pin variants (e.g., MCF51EM128CLL or MCF51EM256CLL) due to fundamental differences in pin count and function allocation. The 80-pin LQFP package omits 20 pins present in the 100-pin version-including PTE0–PTE6, LCD16–LCD20, and several analog/digital I/Os-as documented in Table 4 (Package Pin Assignments). Migration requires PCB redesign and firmware adaptation for missing peripherals.