NXP Semiconductors MC9S08AC8CFJE

Overview

MC9S08AC8CFJE from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 microcontroller featuring a 40-MHz CPU, 8 KB on-chip FLASH, 512 B RAM, and integrated peripherals including dual SCI, SPI, I²C, 8-channel 10-bit ADC, and three 16-bit TPM timer modules. It targets cost-sensitive industrial control and consumer appliance applications requiring reliable embedded control with low-power operation.

For engineers reviewing the MC9S08AC8CFJE datasheet, MC9S08AC8CFJE pinout, MC9S08AC8CFJE application, or MC9S08AC8CFJE equivalent, key selection criteria include its 24-pin QFN package, copper-wire interconnect migration (98ASA00474D), 20-MHz bus frequency, background debug support, and compatibility within the MC9S08ACxx family for firmware reuse across AC8/AC16 variants.

Technical Context

The MC9S08AC8CFJE implements the S08CPUV2 core with HC08 instruction set extension (BGND), supporting single-breakpoint in-circuit debugging and an on-chip debug module with two comparators and nine trigger modes. Its internal clock generator (S08ICGV4) supports multiple modes - FEI, FEE, FBE - with NVM-trimmed internal reference and external crystal/resonator options up to 4 MHz.

Peripherals are tightly coupled to the 20-MHz bus: dual SCI modules support 13-bit break detection; SPI operates in master/slave mode with programmable baud rate; I²C runs at ≤100 kbps under full bus loading; and the ADC includes automatic compare function with 8 input channels and temperature sensor integration.

Key Specifications

Pinout & Package

MC9S08AC8CFJE is housed in a 24-pin QFN package (case outline 98ASA00474D) with 0.5 mm pitch and exposed thermal pad for enhanced thermal dissipation in compact industrial and appliance PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC9S08QG8CDTE and S9S08AW8AVFGE, the MC9S08AC8CFJE offers optimal balance of I²C capability, QFN thermal performance, and industrial-grade operating range (−40°C to +85°C), making it ideal for cost-sensitive non-automotive embedded systems requiring full peripheral integration.

Availability

MC9S08AC8CFJE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor nodes, smart power outlets, and LED lighting controllers requiring stable component supply across multi-year production cycles.

Supply support for MC9S08AC8CFJE 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, formed from the acquisition of Freescale Semiconductor in 2015.

The MC9S08AC8CFJE belongs to the HCS08 AC-series microcontrollers, designed specifically for cost-optimized industrial and consumer control applications demanding robustness, low power, and integrated analog/mixed-signal peripherals without automotive qualification overhead.

FAQ

What is the operating temperature range for the MC9S08AC8CFJE?

The MC9S08AC8CFJE is specified for industrial operation from −40°C to +85°C. This range supports deployment in enclosed control panels, appliance interiors, and factory-floor sensor enclosures without forced cooling. The device's internal temperature sensor and LVD circuitry remain functional across this full span, enabling reliable thermal monitoring and brown-out protection in real-world ambient conditions. All electrical characteristics in the datasheet are guaranteed within this temperature envelope.

Does the MC9S08AC8CFJE support in-circuit debugging without external hardware?

Yes, the MC9S08AC8CFJE supports full in-circuit debugging via its single-pin BKGD/MS interface using the on-chip background debug module (BDM). No external JTAG adapter or debug probe is required - a simple UART-to-BKGD converter suffices for programming, breakpoint setting, register inspection, and real-time variable monitoring. This capability is enabled by default and requires no external pull resistors beyond the internal pullup already present on the BKGD/MS pin.

What clock sources are supported by the MC9S08AC8CFJE internal clock generator?

The MC9S08AC8CFJE internal clock generator (S08ICGV4) supports four primary modes: self-clocked (SCM), FLL-engaged internal (FEI), FLL-bypassed external (FBE), and FLL-engaged external (FEE). It accepts external crystals from 32 kHz to 4 MHz, ceramic resonators, or direct CMOS clock input. Internal NVM trimming ensures ±2% bus frequency accuracy at 20 MHz without external calibration components, reducing BOM count and layout complexity.

How many I/O pins does the MC9S08AC8CFJE provide, and what configuration options are available?

The MC9S08AC8CFJE provides 18 general-purpose I/O pins across Ports A (8 pins) and B (4 pins), plus dedicated pins for RESET, IRQ, BKGD/MS, and clock. Each I/O pin supports software-selectable internal pullups (reducing external resistors), slew rate control (for EMI reduction), and drive strength selection (4 mA or 12 mA). Port pins also share functions with ADC, SCI, SPI, I²C, and TPM peripherals, enabling flexible signal routing without external multiplexers.

Is the MC9S08AC8CFJE pin-compatible with other members of the MC9S08ACxx family?

Yes, the MC9S08AC8CFJE shares identical pinout and package (24-pin QFN, 98ASA00474D) with MC9S08QG8 and MC9S08SH8 within the same family. Firmware developed for MC9S08AC8CFJE can be reused on MC9S08AC16CFJE with only minor linker script and FLASH configuration updates due to memory size differences. Peripheral register maps, interrupt vectors, and clock initialization sequences remain fully compatible across these variants, accelerating design reuse and scalability.