NXP Semiconductors MC9S08SH8CTG

Overview

MC9S08SH8CTG from Freescale Semiconductor is an 8-bit HCS08 microcontroller featuring a 40-MHz CPU, 8 KB flash memory, and integrated peripherals including 10-bit ADC, analog comparator, SCI, SPI, I²C, two TPM modules, RTC, and low-power stop3 mode. It operates from 2.7–5.5 V, supports internal FLL clocking up to 20 MHz bus frequency, and targets cost-sensitive embedded control in industrial sensors and automotive body electronics.

For engineers reviewing the MC9S08SH8CTG datasheet, MC9S08SH8CTG pinout, MC9S08SH8CTG application, or MC9S08SH8CTG equivalent, key selection criteria include its 24-QFN package with exposed pad, single-wire background debug interface, 17 GPIOs with configurable slew rate and pull-ups, and real-time interrupt capability during stop3 mode for ultra-low-power wake-up.

Technical Context

The MC9S08SH8CTG implements the HCS08 CPU core with HC08 instruction set extension (including BGND), supporting up to 32 interrupt/reset sources and on-chip ICE debug module with two comparators and eight-deep FIFO. Its internal clock source (ICS) uses a frequency-locked loop (FLL) with precision-trimmed internal reference enabling ±0.2% resolution and ±2% deviation over voltage and temperature.

Peripherals are designed for deterministic real-time operation: the 10-bit ADC achieves 2.5 µs conversion time and runs in stop3 mode; the analog comparator supports edge-triggered interrupts and routing to TPM; the RTC uses a free-running 1-kHz on-chip low-power oscillator for cyclic wake-up without external components across all MCU modes.

Key Specifications

Pinout & Package

The MC9S08SH8CTG is housed in a 24-pin QFN package (98ASA00474D) with 4×4 mm footprint, 0.5 mm pitch, and thermally enhanced exposed pad for improved power dissipation and grounding.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S08SH8CTG, MC9S08AC16CFGE offers double flash and RAM in a larger package for expanded functionality, while S9KEAZ128AMLH delivers ARM-based performance and modern peripherals in the same 24-QFN footprint-providing either memory headroom or architectural upgrade paths without compromising board space.

Availability

MC9S08SH8CTG is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, home appliance control, and portable medical diagnostics requiring stable component supply and long-term industrial lifecycle support.

Supply support for MC9S08SH8CTG 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

Freescale Semiconductor (now part of NXP Semiconductors since 2015) is a fabless semiconductor company specializing in microcontrollers, analog, and connectivity solutions for automotive, industrial, and consumer markets.

The MC9S08SH8CTG belongs to the HCS08 family-designed specifically for cost-sensitive, low-power embedded control applications requiring robust analog integration, deterministic real-time response, and minimal external components.

FAQ

What is the maximum bus frequency supported by the MC9S08SH8CTG?

The MC9S08SH8CTG supports a maximum bus frequency of 20 MHz, achieved via its internal clock source (ICS) with frequency-locked loop (FLL) and precision-trimmed internal reference. This frequency is validated across the full operating temperature range (–40°C to 125°C) and supply voltage (2.7–5.5 V). The underlying HCS08 CPU core can execute instructions at up to 40 MHz, with instruction throughput dependent on bus speed and addressing mode. MC9S08SH8CTG maintains timing compliance under worst-case conditions without requiring external clock sources.

Does the MC9S08SH8CTG support debugging during low-power operation?

Yes, the MC9S08SH8CTG supports single-wire background debug (BDM) in run, wait, and active background modes-but not in stop2 or stop3 modes. Debug access is disabled during deep stop states to preserve power integrity and security. However, the device retains full functional operation of key peripherals like RTC, ACMP, and ADC in stop3, allowing autonomous wake-up and event handling without debug intervention. MC9S08SH8CTG provides breakpoint capability and on-chip ICE for in-circuit validation prior to entering low-power sequences.

What analog reference options are available for the ADC in the MC9S08SH8CTG?

The MC9S08SH8CTG ADC supports three reference configurations: external VREFH/VREFL pins, internal bandgap reference (1.22 V nominal), and internal VDD as reference. The internal bandgap is factory-trimmed and usable across the full temperature and voltage range, enabling stable 10-bit conversions without external components. Temperature sensor readings are internally referenced to this same bandgap, ensuring correlated accuracy. MC9S08SH8CTG allows runtime selection between references via ADCSC1 register bits, supporting flexible sensor interfacing in varying supply conditions.

Is the MC9S08SH8CTG pin-compatible with other members of the HCS08 SH-series?

No, the MC9S08SH8CTG is not fully pin-compatible with other SH-series variants such as MC9S08SH4 or MC9S08SH16 due to differences in peripheral mapping and pin function allocation-even within the same 24-QFN package. For example, PTB5–PTB7 and PTC0–PTC3 serve different peripheral functions across SH variants, and reset/debug pin behavior varies slightly. MC9S08SH8CTG must be treated as a distinct pinout configuration; PCB layout cannot be reused across SH-series parts without verification against individual device-specific pin assignment tables.

What is the purpose of the exposed thermal pad on the MC9S08SH8CTG QFN package?

The exposed thermal pad on the MC9S08SH8CTG's 24-QFN package (98ASA00474D) serves dual purposes: thermal dissipation and low-impedance ground connection. It must be soldered to a solid copper pour tied to VSS to ensure reliable operation under sustained 40-MHz CPU activity and peripheral use. Improper pad connection causes elevated junction temperature, potential timing violations, and reduced flash endurance. MC9S08SH8CTG datasheet specifies minimum solder coverage (≥90%) and recommends thermal vias to inner ground planes-critical for automotive and industrial applications where ambient temperatures exceed 85°C.