8-bit MCU for cost-sensitive control — 40 MHz, 16 KB Flash, 20-TSSOP
The NXP MC9S08SH16CTJ is an 8-bit microcontroller from the S08 family, built around the S08 core processor. It runs at 40 MHz and carries 16 KB of Flash program memory with 1K x 8 of RAM — a configuration sized for embedded control loops, sensor readout, and simple communication bridges rather than data-heavy applications. The 20-TSSOP package keeps board area small, and the wide supply range (2.7 V to 5.5 V) lets it sit on a regulated 3.3 V rail or a direct 5 V logic bus without a separate level shifter for the MCU itself. On-chip peripherals include a 12-channel 10-bit ADC, PWM, watchdog timer, and low-voltage detect (LVD) with power-on reset (POR). Connectivity covers I²C, SCI (UART), SPI, and LINbus — enough for a LIN slave node in an automotive body module or a sensor hub in an industrial sensor pod. The operating temperature range is -40°C to 85°C, which qualifies it for factory-floor enclosures, outdoor telecom cabinets, and under-hood automotive auxiliary modules where the ambient stays below the 85°C ceiling.
Supply and temperature — what the ratings mean for the BOM
The 2.7 V to 5.5 V supply range means this MCU can run directly from a 3.6 V Li-ion cell or a 5 V industrial rail without an external regulator, saving a BOM line. At the low end, 2.7 V is above the typical brownout threshold of a 3.3 V system, so a 3.3 V rail with 5% tolerance (3.135 V min) still holds margin. The -40°C to 85°C industrial temperature grade covers most factory automation, outdoor telecom, and automotive cabin-zone applications. If the end system sees sustained junction temperatures above 85°C, this part is not the fit — the 85°C ceiling is the absolute operating limit, not a derating target.
Lifecycle — active, no LTB risk
The MC9S08SH16CTJ carries an Active lifecycle status from NXP. The part is ROHS3 compliant, which covers the current EU exemption regime for lead-free assembly.