NXP Semiconductors MC908LJ24CPBER

Overview

MC908LJ24CPBER from NXP Semiconductors (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 MC908LJ24CPBER datasheet, MC908LJ24CPBER pinout, MC908LJ24CPBER application, or MC908LJ24CPBER equivalent, key selection criteria include its 48-pin LQFP package, 3.3–5.5 V operating range, RTC calendar/alarm functions, IR transmit/receive capability per IrDA SIR PHY, and Flash block protection configuration.

Technical Context

The MC908LJ24CPBER implements the HCS08 CPU core with 16-bit address space, 8-level hardware stack, and COP watchdog. Its Clock Generator Module (CGM) supports internal RC oscillator (1–8 MHz), external crystal (up to 8 MHz), and PLL-based frequency multiplication for system clock scaling.

System integration includes a 16-channel 10-bit ADC with programmable reference, 8-channel PWM with buffered/unbuffered modes, and dual 16-bit timer channels with input capture and output compare. The IRSCI module integrates both infrared encoder/decoder and standard SCI UART functionality on shared pins PTB0/TxD and PTB1/RxD.

Key Specifications

Pinout & Package

MC908LJ24CPBER 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 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 MC908LJ12CPBE, the MC908LJ24CPBER provides 100% more Flash and RAM for complex state machines and data logging; versus MC9S08LG32CPBE, it offers identical pin compatibility but trades off CAN and higher-speed operation for lower cost and proven qualification in legacy designs.

Availability

MC908LJ24CPBER is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial HMI panels, and smart utility meter interfaces requiring stable component supply across multi-year production cycles.

Supply support for MC908LJ24CPBER 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 communication infrastructure markets.

The MC908LJ24CPBER belongs to the legacy HCS08 microcontroller family, designed specifically for cost-sensitive, low-power embedded control applications requiring integrated LCD, RTC, and infrared communication - especially where long-term supply stability and mature toolchain support are critical.

FAQ

What is the maximum operating frequency of the MC908LJ24CPBER?

The MC908LJ24CPBER supports a maximum system clock frequency of 8 MHz when driven by an external crystal or the internal PLL. Its HCS08 core executes instructions at one cycle per bus clock, enabling deterministic timing for real-time control loops and interrupt service routines in applications such as motor control and sensor polling.

Does the MC908LJ24CPBER support in-circuit debugging?

Yes, the MC908LJ24CPBER supports background debug mode (BDM) via the dedicated BKGD pin. This allows full non-intrusive debugging - including breakpoints, single-stepping, and memory inspection - without requiring dedicated debug hardware beyond a standard BDM interface cable and compatible IDE.

Can the MC908LJ24CPBER drive a 4×32 segment LCD directly?

Yes, the MC908LJ24CPBER's integrated LCD driver supports up to 4 commons and 32 segments (128 segments total) with internal VLCD generation. It requires only external resistors for contrast control and does not need external charge pumps or bias generators - simplifying layout and reducing bill-of-materials cost.

What is the purpose of the CGMXFC pin on the MC908LJ24CPBER?

The CGMXFC pin on the MC908LJ24CPBER connects an external filter capacitor to stabilize the PLL's loop filter. It is required when the Clock Generator Module operates in PLL mode to ensure reliable lock acquisition and low-jitter output - typically populated with a 10 nF ceramic capacitor to VSSA near the pin.

How does the MC908LJ24CPBER handle power-on reset and brown-out conditions?

The MC908LJ24CPBER incorporates a built-in Low-Voltage Inhibit (LVI) circuit that asserts a reset when VDD drops below 2.7 V (typical). Combined with Power-On Reset (POR), this ensures reliable initialization and prevents erratic behavior during power ramp-up or supply sag - critical for systems deployed in unregulated environments.