NXP Semiconductors MC9S08JS8CFK

Overview

MC9S08JS8CFK from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 microcontroller with 8 KB flash, 512 bytes RAM, and integrated USB 2.0 full-speed transceiver. It operates at up to 48 MHz CPU frequency and 24 MHz bus speed, supports crystal/resonator/external clock inputs via MCG, and targets low-power embedded control in USB-connected industrial sensors and human-interface devices.

For engineers reviewing the MC9S08JS8CFK datasheet, MC9S08JS8CFK pinout, MC9S08JS8CFK application, or MC9S08JS8CFK equivalent, this page delivers verified technical context, package mapping, real-world use scenarios, and validated alternative options - all grounded in Freescale's official MC9S08JS16 Series Data Sheet Rev. 4 and QFN Addendum Rev. 0.

Technical Context

The MC9S08JS8CFK implements the HCS08 CPU core with a multi-purpose clock generator (MCG) supporting FLL and PLL modes, enabling flexible clock synthesis from internal reference (32.7 kHz trimmed), external crystal (up to 16 MHz), or square-wave input. Its USB module integrates a dedicated 3.3 V regulator (VUSB33) and full-speed transceiver compliant with USB 2.0 at 12 Mbps.

It features a 24-pin QFN package (case 1982-01, 98ASA00734D) with copper-wire interconnect, supports Wait + two Stop power-saving modes, and includes hardware CRC16-CCITT generation, real-time counter (RTC), keyboard interrupt (KBI), and dual-channel TPM with PWM and input capture. All I/O pins offer software-selectable pullups, slew rate, and drive strength.

Key Specifications

Pinout & Package

MC9S08JS8CFK uses a 24-pin QFN package (case 1982-01, 98ASA00734D) with 0.5 mm pitch and thermally enhanced exposed pad. Pin functions are identical to the MC9S08JS16 series per Freescale's MC9S08JS16 Data Sheet Rev. 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S08JS8CFK, MC9S08JS16CFK offers double flash capacity with zero hardware changes, while S9KEAZ128AMLH provides scalable 32-bit performance at the cost of firmware rework and increased power in active mode.

Availability

MC9S08JS8CFK is available at Aetrix Electronics and suitable for industrial USB sensor nodes, human-interface devices, diagnostic tools, and low-power peripheral controllers requiring stable component supply and long-term manufacturability.

Supply support for MC9S08JS8CFK 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 full technical support, documentation, and product continuity for the HCS08 portfolio.

The MC9S08JS8CFK belongs to the HCS08 JS-series, designed specifically for cost-sensitive, USB-enabled embedded control applications where integration, low power, and small footprint are critical - not general-purpose computing or high-speed signal processing.

FAQ

What is the maximum operating frequency of the MC9S08JS8CFK CPU core?

The MC9S08JS8CFK CPU core runs at up to 48 MHz, with a corresponding 24 MHz bus frequency. This is achieved in PEE (Phase-Locked Loop Enabled) mode using the internal MCG with an external crystal or resonator. The core supports multiple clock modes including FEI, FEE, FBE, PBE, BLPE, and BLPI to balance performance, accuracy, and power consumption based on system requirements. MC9S08JS8CFK achieves deterministic real-time response within its 8-bit architecture.

Does the MC9S08JS8CFK include an integrated USB transceiver and regulator?

Yes, the MC9S08JS8CFK integrates a full-speed USB 2.0 transceiver compliant with 12 Mbps operation and a dedicated on-chip 3.3 V regulator (VUSB33). This eliminates the need for external USB PHY ICs or discrete LDOs in most endpoint designs. The VUSB33 pin must be decoupled with a 1 μF ceramic capacitor, and USBDP/USBDN require 15.1 kΩ pull-down resistors per USB specification. MC9S08JS8CFK meets USB suspend current requirements at 273.3 μA.

What package type and pin count does the MC9S08JS8CFK use?

The MC9S08JS8CFK uses a 24-pin quad flat no-lead (QFN) package measuring 4 mm × 4 mm with 0.5 mm pitch and an exposed thermal pad. Its mechanical outline is defined as case 1982-01, with package document number 98ASA00734D (copper-wire version). This matches the pin assignments and electrical characteristics of the MC9S08JS16 series per Freescale's official datasheet. MC9S08JS8CFK shares identical pinout with MC9S08JS16CFK.

How much flash and RAM memory does the MC9S08JS8CFK provide?

The MC9S08JS8CFK includes 8 KB of on-chip in-circuit programmable flash memory with block protection and security options, plus 512 bytes of general-purpose RAM and 256 bytes of dedicated USB RAM. The flash supports mass erase and partial erase (excluding first 1 KB) via the built-in USB bootloader ROM. These memory resources are optimized for compact USB HID firmware, sensor drivers, and control logic. MC9S08JS8CFK delivers sufficient space for certified USB descriptors and application code without external memory.

What power-saving modes are supported by the MC9S08JS8CFK?

The MC9S08JS8CFK supports Wait mode plus two Stop modes (Stop2 and Stop3). Stop3 achieves 1.5 μA typical supply current at 5 V with all modules disabled, and adds only 300 nA for RTC operation or 106.7 μA for low-voltage detection. The COP watchdog can operate from an independent 1 kHz internal clock during Stop modes, ensuring reliable recovery without external timing sources. MC9S08JS8CFK enables battery-powered USB peripherals with multi-year operational life in duty-cycled applications.