NXP Semiconductors MC9S08QE4CWJ

Overview

MC9S08QE4CWJ from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 microcontroller with 4 KB flash, 256 B RAM, and integrated peripherals including 12-bit ADC, dual analog comparators, SCI, SPI, I²C, two 3-channel TPMs, RTC, and low-power stop3 mode. It operates from 1.8 V to 3.6 V at up to 20 MHz and targets battery-powered sensor nodes and industrial control interfaces.

For engineers reviewing the MC9S08QE4CWJ datasheet, MC9S08QE4CWJ pinout, MC9S08QE4CWJ application, or MC9S08QE4CWJ equivalent, this page delivers verified electrical specs, QFN-32 package mapping, real-time counter operation in stop3, 6 µs wake-up time, and confirmed alternative parts for cost or availability trade-offs.

Technical Context

The MC9S08QE4CWJ implements the HCS08 CPU core with BGND instruction support and handles up to 32 interrupt/reset sources. Its internal clock source (ICS) uses a frequency-locked loop (FLL) with factory-trimmed internal reference (±2% over voltage/temperature), enabling bus frequencies from 1 MHz to 10 MHz without external crystal.

System-level protection includes COP watchdog with 1 kHz internal clock option, low-voltage detection (1.84–1.96 V reset threshold), illegal opcode/address detection, and flash block protection. The 12-bit ADC supports 10 channels, 2.5 µs conversion, temperature sensing (1.7 mV/°C), and operation in stop3 mode.

Key Specifications

Pinout & Package

MC9S08QE4CWJ is housed in a 32-pin QFN package (case 2078-01, exposed pad), measuring 5 mm × 5 mm × 0.85 mm, with thermal resistance θ_JA = 110 °C/W (single-layer board). The exposed pad must be soldered to PCB ground for thermal and EMI performance per EB806 guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S08QE4CWJ, MC9S08QE8CWJ offers double flash/RAM in identical QFN-32 packaging for seamless upgrade, while S9KEAZ128AMLH provides ARM-based scalability at the cost of higher power and layout redesign - making MC9S08QE4CWJ optimal for cost-sensitive, ultra-low-power embedded control where 8-bit performance suffices.

Availability

MC9S08QE4CWJ is available at Aetrix Electronics and suitable for industrial sensor nodes, smart thermostat interfaces, portable medical monitors, and asset tracking beacons requiring stable component supply and long-term manufacturability.

Supply support for MC9S08QE4CWJ 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 longevity for the legacy HCS08 portfolio.

The MC9S08QE4CWJ belongs to the QE-series microcontrollers designed specifically for energy-constrained industrial and consumer applications demanding sub-µA stop-mode operation, integrated analog front-ends, and robust debug capability in minimal footprint.

FAQ

What is the maximum operating frequency of the MC9S08QE4CWJ?

The MC9S08QE4CWJ supports a maximum bus frequency of 10 MHz when using the internal clock source (ICS) with FLL enabled. At 3.6 V and 25 °C, the HCS08 core can execute instructions at up to 20 MHz, but system timing is governed by the bus clock. External crystal operation (XOSC) supports up to 16 MHz input, though bus frequency remains limited to 10 MHz by the ICS divider architecture. This constraint ensures stable operation across the full 1.8–3.6 V supply range and –40 °C to 85 °C temperature span.

Does the MC9S08QE4CWJ support debugging via SWD or JTAG?

No, the MC9S08QE4CWJ does not support SWD or JTAG. It uses Freescale's proprietary single-wire background debug (BDM) interface accessed through the PTA4/BKGD pin. This interface enables breakpoint setting, memory inspection, and register access during in-circuit debugging. The on-chip debug module includes two comparators and nine trigger modes, with an eight-deep FIFO for change-of-flow tracing. A compatible BDM pod (e.g., USB-BDM Multilink) is required - standard ARM debug probes are incompatible.

Can the MC9S08QE4CWJ operate from a single 1.8 V supply?

Yes, the MC9S08QE4CWJ is fully specified to operate from 1.8 V to 3.6 V across its entire temperature range (–40 °C to 85 °C). At 1.8 V, the maximum bus frequency is reduced to ensure timing margins: ICS-FLL mode supports up to 1 MHz, and external crystal operation is limited to 31.25–38.4 kHz or 1–4 MHz ranges. All peripherals - including the 12-bit ADC, analog comparators, and RTC - remain functional at 1.8 V, with ADC accuracy maintained via internal bandgap reference and temperature sensor calibration.

What is the purpose of the exposed pad on the MC9S08QE4CWJ QFN package?

The exposed pad on the MC9S08QE4CWJ's 32-pin QFN package serves dual thermal and electrical functions: it must be soldered to a PCB copper pour connected to VSS to dissipate heat and reduce junction temperature, and it provides a low-inductance ground return path critical for ADC noise performance and EMI suppression. Per Freescale EB806 guidelines, the pad should be divided into 4–9 thermal vias (0.3 mm diameter) connecting to inner ground planes. Leaving the pad unconnected or floating degrades thermal resistance by >40% and increases analog measurement error by up to 3 LSB.

How does the MC9S08QE4CWJ handle low-voltage conditions?

The MC9S08QE4CWJ incorporates three-tiered voltage monitoring: low-voltage warning (LVW) triggers an interrupt at 2.14–2.24 V (falling), low-voltage detection (LVD) asserts reset at 1.84–1.96 V (falling), and POR re-arms only above 1.4 V. Hysteresis of 80 mV prevents reset oscillation during brown-out. During LVD reset, flash and RAM contents are preserved if supply remains ≥0.6 V (VRAM retention). These features enable graceful shutdown in battery-powered systems - for example, saving sensor calibration data to flash before power loss.