NXP Semiconductors MC9S08QB8CWL

Overview

MC9S08QB8CWL from NXP (formerly Freescale) is an 8-bit HCS08 microcontroller designed for ultra-low-power battery-operated systems. It features 8 KB flash, 512 B RAM, 8-channel 12-bit ADC, UART, TPM, analog comparator, and keyboard interrupt module, operating from 1.8 V to 3.6 V at up to 20 MHz CPU speed across –40°C to +85°C - ideal for smoke detectors and garage door openers.

For engineers reviewing the MC9S08QB8CWL datasheet, MC9S08QB8CWL pinout, MC9S08QB8CWL application, or MC9S08QB8CWL equivalent, key selection criteria include its 6 µs wake-up time from stop mode, dual ultra-low-power stop modes with peripheral retention, 12-bit ADC operation in low-power stop, clock gating for unused peripherals, and 28-pin SOIC package compatibility with QE8 family devices.

Technical Context

The MC9S08QB8CWL implements the HCS08 CPU core with backward object-code compatibility to 68HC08/68HC05, enabling reuse of legacy firmware libraries. Its Internal Clock Source (ICS) integrates a frequency-locked loop (FLL) configurable with internal or external reference, supporting dynamic frequency scaling to reduce current draw.

Peripherals are managed via clock gating registers, and the device supports two ultra-low-power stop modes: one allowing limited peripheral operation (e.g., ADC sampling), and another with full peripheral disablement. The 16-bit Timer/PWM (TPM) module offers input capture, output compare, and edge- or center-aligned PWM, relocatable to PTA0 or PTB5.

Key Specifications

Pinout & Package

MC9S08QB8CWL is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package, 300 mil width, with 0.025 inch pitch and standard JEDEC MS-012AC footprint. Pin assignments follow the QB8 28-pin SOIC variant defined in Freescale document 9S08QB84FS REV 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S08QB8CWL, MC9S08QE8CWL trades flash capacity for SPI and debug enhancements, while MC9S08SH8CTJ sacrifices ADC resolution, KBI, and package pin count for smaller footprint - making MC9S08QB8CWL optimal for cost-sensitive, battery-life-critical applications needing 12-bit sensing and keypad support in 28-pin SOIC.

Availability

MC9S08QB8CWL is available at Aetrix Electronics and suitable for smoke detectors, garage door openers, remote window shutters, and battery-operated toys requiring stable component supply, long-term lifecycle assurance, and industrial-grade temperature performance.

Supply support for MC9S08QB8CWL 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 company formed from the spin-off of Freescale Semiconductor and Philips' semiconductor division, specializing in secure connectivity and embedded processing solutions.

The MC9S08QB8CWL belongs to the S08QB family - engineered specifically for ultra-low-power, cost-sensitive portable applications where extended battery life, small footprint, and integrated analog peripherals are essential design requirements.

FAQ

What is the minimum operating voltage for the MC9S08QB8CWL?

The MC9S08QB8CWL operates down to 1.8 V across its full industrial temperature range (–40°C to +85°C), maintaining full functionality including 20 MHz CPU speed and 12-bit ADC operation. This enables direct integration with single-cell lithium or two-cell alkaline batteries without voltage regulation, reducing bill-of-materials cost and quiescent current overhead in the MC9S08QB8CWL design.

Does the MC9S08QB8CWL support in-application programming of flash memory?

Yes, the MC9S08QB8CWL supports full read/program/erase of its 8 KB flash memory across the entire 1.8–3.6 V operating voltage range and –40°C to +85°C temperature range. This capability allows field firmware updates and parameter storage without requiring external programmers, and flash block protection prevents accidental overwrite of critical sections in the MC9S08QB8CWL application.

Can the MC9S08QB8CWL's ADC operate during low-power stop mode?

Yes, the MC9S08QB8CWL's 12-bit ADC remains fully functional in one of its two ultra-low-power stop modes, enabling continuous background sampling without waking the CPU. This feature is confirmed in Freescale document 9S08QB84FS REV 2 and directly supports battery-life-critical use cases such as smoke detector ambient monitoring in the MC9S08QB8CWL implementation.

What is the wake-up time from stop mode for the MC9S08QB8CWL?

The MC9S08QB8CWL achieves a typical wake-up time of 6 µs from ultra-low-power stop mode, measured from interrupt assertion to first CPU instruction execution. This specification is guaranteed across voltage (1.8–3.6 V) and temperature (–40°C to +85°C) ranges, ensuring deterministic real-time response in safety-critical applications like smoke alarm activation using the MC9S08QB8CWL.

Is the MC9S08QB8CWL pin-compatible with other S08 family devices?

Yes, the MC9S08QB8CWL in 28-pin SOIC package is pin-compatible with the MC9S08QE8CWL, sharing identical pin functions and electrical characteristics per Freescale documentation. This allows drop-in replacement in existing QE8-based designs, though firmware must be verified for QB8-specific register mappings and peripheral differences before deploying the MC9S08QB8CWL.