NXP Semiconductors MC908LJ24CFQE

Overview

MC908LJ24CFQE from NXP (formerly Freescale) is an 8-bit HCS08 microcontroller with 24 KB on-chip Flash, 1 KB RAM, and integrated LCD driver supporting up to 32 segments. It features a real-time clock (RTC), IRSCI infrared serial interface, SPI, I²C, 10-bit ADC, and PWM-capable TIM module. Designed for low-power embedded control in portable instrumentation and industrial HMI panels.

For engineers reviewing the MC908LJ24CFQE datasheet, MC908LJ24CFQE pinout, MC908LJ24CFQE application, or MC908LJ24CFQE equivalent, key selection criteria include its 48-pin QFP package, 3.3 V/5 V operation, SuperFlash® endurance (100k erase/write cycles), RTC calendar/alarm functions, and IRSCI compliance with IrDA 1.0 physical layer timing.

Technical Context

The MC908LJ24CFQE implements the HCS08 CPU core with 16-bit address space, 8-level hardware stack, and low-power wait/stop modes. Its Clock Generator Module (CGM) integrates a PLL for flexible bus clock derivation from internal RC or external crystal sources, enabling precise timing control for RTC and IRSCI.

System integration includes a System Integration Module (SIM) managing reset sources (POR, LVI, COP), interrupt prioritization across 16 vectors, and memory protection via CONFIG registers. The IRSCI module supports both infrared encoding/decoding and standard SCI UART operation on shared pins PTB0/TxD and PTB1/RxD.

Key Specifications

Pinout & Package

MC908LJ24CFQE is housed in a 48-pin LQFP (7 mm × 7 mm, 0.5 mm pitch) package with exposed thermal pad. Pin assignments are defined per Section 1.5 ("Pin Assignments") and Section 1.6 ("Pin Functions") of the Freescale MC68HC908LJ24/LK24 Rev. 2.1 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908LJ24CFQE, the MC908LJ12CFQE offers identical peripheral functionality at lower memory cost, while the S9KEAZN64ACLH provides modern 32-bit performance but necessitates redesign for LCD and IR interfaces-making MC908LJ24CFQE optimal for cost-constrained, display-centric 8-bit control.

Availability

MC908LJ24CFQE is available at Aetrix Electronics and suitable for portable medical devices, industrial HMI panels, energy meter displays, and smart thermostat interfaces requiring stable component supply and long-term lifecycle support.

Supply support for MC908LJ24CFQE 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 MC908LJ24CFQE belongs to the HCS08 microcontroller family, engineered for ultra-low-power, mixed-signal embedded control in resource-constrained devices with integrated human interface requirements.

FAQ

What is the maximum operating frequency of the MC908LJ24CFQE?

The MC908LJ24CFQE supports a maximum bus clock frequency of 8 MHz when using the internal oscillator or external crystal. With its integrated PLL, the CGM can generate higher internal clocks for peripherals while maintaining the 8 MHz bus limit. This frequency is confirmed in Section 8.4.2 ("Phase-Locked Loop Circuit") and electrical specifications tables of the MC68HC908LJ24/LK24 Rev. 2.1 datasheet. The MC908LJ24CFQE delivers deterministic real-time response within this constraint.

Does the MC908LJ24CFQE support in-system programming (ISP)?

Yes, the MC908LJ24CFQE supports in-system programming via its Monitor ROM (MON), which occupies 1 KB of on-chip memory. MON provides flash programming routines (PRGRNGE, ERARNGE), secure entry via break signal, and baud-rate configurable serial interface-enabling field firmware updates without dedicated programmers. This capability is documented in Section 10 ("Monitor ROM") of the MC68HC908LJ24/LK24 Rev. 2.1 datasheet. The MC908LJ24CFQE leverages SuperFlash® technology to allow byte-level writes and sector erases during runtime.

How many LCD segments can the MC908LJ24CFQE drive directly?

The MC908LJ24CFQE integrates a dedicated LCD driver capable of directly controlling up to 32 segments and 4 commons, supporting static, 2-mux, 3-mux, and 4-mux configurations. This is implemented through Port F (PTF0–PTF7) and additional segment pins mapped to Port C and Port D, as specified in Section 17 ("Liquid Crystal Display (LCD) Driver") of the MC68HC908LJ24/LK24 Rev. 2.1 datasheet. The MC908LJ24CFQE eliminates need for external LCD drivers in compact display applications.

What low-power modes does the MC908LJ24CFQE offer, and what is typical current draw in each?

The MC908LJ24CFQE supports Wait Mode (CPU halted, peripherals active) and Stop Mode (all clocks stopped except RTC oscillator). Typical current in Wait Mode is 100 µA at 3.3 V; in Stop Mode with RTC running, it drops to 1.5 µA. These values are specified in Section 24.3 ("DC Electrical Characteristics") of the MC68HC908LJ24/LK24 Rev. 2.1 datasheet. The MC908LJ24CFQE achieves sub-µA wake-on-keypress via KBI module, making it ideal for battery-operated UIs.

Is the MC908LJ24CFQE RoHS compliant and lead-free?

Yes, the MC908LJ24CFQE is RoHS compliant and lead-free, as confirmed by NXP's official product change notices and packaging markings. The "FQE" suffix denotes a lead-free, halogen-free, 48-pin LQFP package conforming to JEDEC J-STD-020 moisture sensitivity level 3. This compliance is consistent with Freescale's transition to green manufacturing completed prior to 2006. The MC908LJ24CFQE meets EU Directive 2011/65/EU and subsequent amendments without exemptions.