MC9S08SH8CFK - 8-Bit 40MHz S08SH MCU, 8KB Flash, 24-QFN | NXP
MPN: MC9S08SH8CFK ✗ End of LifeMC9S08SH8CFK Overview
An 8-bit MCU (microcontroller unit) is a single integrated circuit containing a CPU core, program memory, data memory and peripherals such as analog converters and serial interfaces. The MC9S08SH8CFK belongs to the HCS08 family, whose enhanced HCS08 core uses the HC08 instruction set plus a BGND background-debug instruction and supports up to 32 interrupt and reset sources, giving it more headroom than a minimal 8051-class part.
Key features include a 40 MHz maximum CPU frequency, an on-chip 12-channel 10-bit ADC with a 2.5 microsecond conversion time, an automatic compare function and an integrated temperature sensor. Serial connectivity includes SCI, SPI and I2C interfaces, so the part can host sensors, displays and transceivers without external interface expanders. The device is fabricated on a 0.25 micron process and is qualified for the 5-volt operating class typical of cost-driven consumer and industrial control products.
The 24-pin QFN-EP (4x4 mm) footprint keeps the board area small and exposes a pad for improved thermal performance, which matters because the core runs continuously. Unlike larger 8-bit devices, this part keeps pin count and cost low while retaining a fast clock for time-critical control loops, timer-driven commutation or simple sensor conditioning.
Typical applications include small motor and fan controllers, thermostat and HVAC front panels, appliance control boards, LED driver control logic, battery-powered sensor nodes using the low-power modes, and simple serial-to-digital acquisition nodes where a 10-bit ADC is sufficient.
When designing around the MC9S08SH8CFK, confirm the supply voltage range and flash endurance requirements in the manufacturer datasheet before committing firmware, and keep the exposed pad soldered with a thermal via array so the 40 MHz core does not throttle in enclosed enclosures.
This page consolidates the manufacturer product information, package and pin-count details, drop-in alternatives and practical design guidance for engineers evaluating a 5-volt 8-bit control node, adding engineering context that the raw datasheet does not provide.
Drop-in alternatives for MC9S08SH8CFK — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC9S08SH8CFK (same form factor and footprint) — differing in ADC, Mounting Type, Supply Voltage Range, Package, Product Type.
MC9S08QG8CFKE
✅ Drop-InContact for price
View Datasheet →MC9S08SH4CFK
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MC9S08SH2CFK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08SG8CFK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08QG4CFKE
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MC9S08SH8CFK Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Manufacturer | NXP Semiconductors (formerly Freescale Semiconductor) |
| Family | S08SH (HCS08 low-cost 5 V family) |
| CPU Core | Enhanced HCS08 core, HC08 instruction set with BGND instruction |
| Maximum CPU Frequency | 40 MHz |
| Program Memory (Flash) | 8 KB (8K x 8) |
| ADC | 12-channel, 10-bit resolution, 2.5 us conversion time |
| ADC Features | Automatic compare function, integrated temperature sensor |
| Serial Interfaces | SCI, SPI, I2C |
| Interrupt Sources | Up to 32 interrupt/reset sources |
| Supply Class | 5-volt range low-end S08SH positioning |
| Process Technology | 0.25 um |
| Package Type | QFN-24 with exposed pad (QFNL), 4 x 4 mm, 1 mm height |
| Package Outline | MO-220VGGD-6 |
| Pin Count | 24 pins |
| Mounting Type | Surface Mount |
| Tool and Software Compatibility | Pin, tool and software compatible with S08SG family |
MC9S08SH8CFK mo-220vggd-6 Pin Configuration Guide
Pin configuration for MC9S08SH8CFK (mo-220vggd-6 package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MC9S08SH8CFK.
Refer to the datasheet for full pin configuration.
Typical Applications
MC9S08SH8CFK is suitable for 6 applications: 5-Volt Appliance Control Board, Small Motor and Fan Controller, Thermostat and HVAC User Interface, Battery-Powered Sensor Node, LED Driver and Lighting Control, Simple Serial Data Acquisition Node.
5-Volt Appliance Control Board
The MC9S08SH8CFK fits appliance control boards that need a handful of digital outputs, a few analog inputs and reliable low-cost logic on a 5-volt rail. At 40 MHz the HCS08 core executes motor-timer and state-machine code quickly, while the 12-channel 10-bit ADC with 2.5 us conversion time reads thermistors or level sensors without an external converter. The 24-QFN (4x4 mm) package with exposed pad saves board area next to relays and triacs, and SCI or SPI connects to a display or keypad daughter board. With 8 KB of Flash there is room for a bootloader stub plus application code, and the S08SH family's low-cost positioning keeps the bill of materials aligned with consumer appliance budgets.
Recommended
Small Motor and Fan Controller
For small fan, pump and stepper-motor control the MC9S08SH8CFK combines a fast core with timer-driven PWM output in a compact package. A 40 MHz clock allows precise edge timing and closed-loop duty adjustment, and the on-chip 10-bit ADC closes the loop on current or speed feedback without an external analog front end. Because the exposed pad of the 24-QFN (4x4 mm) package can be tied to a ground pour, the device dissipates its internal drive and timer power with a modest thermal footprint, which matters in a sealed appliance. The S08SH family's SCI link is useful for reporting speed or fault status to a parent controller, while I2C can host an external sensor or EEPROM for calibration storage.
Recommended
Thermostat and HVAC User Interface
Thermostat front panels demand accurate ambient sensing, a stable display and a simple keypad scan, all on a 5-volt budget. The MC9S08SH8CFK supplies a 12-channel 10-bit ADC whose 2.5 us conversion time supports multi-channel thermistor scanning, and its integrated temperature sensor gives a convenient internal reference for offset calibration. The 40 MHz core leaves ample cycles for debounce, hysteresis and PID-style setpoint control, while the 8 KB of Flash holds the control algorithm and display routines. Its 24-QFN (4x4 mm) footprint with exposed pad allows a slim wall-plate PCB, and the SCI or I2C interface can drive an LCD module or link to a building automation board.
Recommended
Battery-Powered Sensor Node
Distributed sensing nodes need low standby current, compact area and a serial link back to a gateway. The MC9S08SH8CFK suits these designs because the S08SH family targets cost-driven low-power systems with a 5-volt class supply and multiple serial interfaces; SPI suits a digital sensor, I2C suits a low-rate sensor bus and SCI provides a simple uplink. The 24-QFN (4x4 mm) package with exposed pad keeps the node compact, and the 40 MHz clock lets the firmware sleep between samples, wake, acquire and transmit quickly, which shortens the active window and reduces average energy. Its 8 KB of Flash is sufficient for a sampling routine, a simple filtering chain and a compact protocol stack.
Recommended
LED Driver and Lighting Control
LED lighting modules often need accurate current regulation, dimming and fault reporting in a small, inexpensive controller. The MC9S08SH8CFK pairs a 40 MHz HCS08 core with a 12-channel 10-bit ADC, letting it monitor several LED string voltages or thermistor sensors for thermal derating, and timer outputs can generate the PWM dimming signal. Because the device is a low-cost 5-volt-class part in a 4 x 4 mm QFN with an exposed pad, it can sit directly on a small driver board alongside the switching stage without dominating the layout. The SCI interface allows dimming commands and status reporting from a remote controller, and the S08 family BGND debug instruction supports in-circuit debugging without consuming extra pins.
Recommended
Simple Serial Data Acquisition Node
When a compact acquisition module must gather a handful of analog channels and forward them, the MC9S08SH8CFK integrates everything needed on one board. The 12-channel 10-bit ADC with 2.5 us conversion time can sample a full scan in well under a millisecond, and the 40 MHz core handles scaling, filtering and framing without offloading to an external processor. The on-board SCI and SPI interfaces allow a host to pull data over a simple UART or a sensor to feed data in through SPI, while I2C supports configuration EEPROMs. Packaged in a 24-QFN (4x4 mm) outline with an exposed pad, the device supports very small remote telemetry nodes that must run from a 5-volt line or regulated supply.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08SH8CFK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08QG8CFKE | MC9S08SH4CFK | MC9S08SH2CFK | MC9S08SG8CFK | MC9S08QG4CFKE |
|---|---|---|---|---|---|---|
| Package | 24-QFN-EP (4x4 mm) | 24-QFN-EP (4x4 mm) - same | 24-QFN-EP (4x4 mm) - same | 24-QFN-EP (4x4 mm) - same | 24-QFN-EP (4x4 mm) - same | 24-QFN-EP (4x4 mm) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Maximum CPU Frequency | 40 MHz | 40 MHz class | 40 MHz | 40 MHz | 40 MHz class | 40 MHz class |
| Flash Program Memory | 8 KB (8K x 8) | 8 KB | 4 KB (-50%) | 2 KB (-75%) | 8 KB | 4 KB (-50%) |
| Pin Count | 24 pins | 24 pins | 24 pins | 24 pins | 24 pins | 24 pins |
Key Differentiators
- Full 8 KB of Flash in the 24-pin QFN footprint (vs MC9S08SH4CFK)
- Pin, tool and software compatibility with the S08SG family (vs MC9S08SG8CFK)
- 12-channel 10-bit ADC with integrated temperature sensor on-chip (vs MC9S08QG8CFKE)
- Up to 32 interrupt and reset sources for time-critical control (vs MC9S08SH2CFK)
- 24-QFN (4x4 mm) area versus 20-pin SOIC options in the same family (vs MC9S08SH8CWJ)
Design Notes
The 24-QFN-EP (4x4 mm) package exposes a thermal pad that must be soldered to a ground plane, not left floating. Estimate the internal dissipation from the core and I/O activity at 40 MHz, then spread heat through a via array under the pad into an inner ground plane; keep exposed-pad vias within the manufacturer's land-pattern limits to avoid solder wicking during reflow. In an enclosed appliance with limited convection, this copper path is the only heat sink the device has.
Place the 0.1 uF decoupling capacitors from each supply pin directly to the ground plane, with the shortest possible via path, and reserve a bulk capacitor near the supply entry point. Because the device can be clocked at 40 MHz, keep the supply loop area minimal: route VDD and its return current as a tight pair rather than letting the return path wander through the board. Place the exposed pad via array on a solid, uninterrupted ground region to avoid thermalspilling.
The most common migration error is substituting a lower-Flash sibling without auditing code size: MC9S08SH4CFK and MC9S08SH2CFK share the 24-QFN footprint but halve and quarter the program memory. Verify the linked image size, vector table placement and bootloader assumptions after any swap. A second common error is assuming 5-volt-only logic tolerance on every I/O; check the individual pin voltage limits in the manufacturer datasheet before connecting a 3.3-volt sensor to a 5-volt rail.
For designs using the on-chip 10-bit ADC, route the analog inputs away from the SCI and SPI pins and keep the analog ground return tight to the device ground pad. Use a dedicated via stitch from the analog section into the ground plane and avoid routing switching-node or relay-coil traces beneath the QFN. Since the ADC converts in 2.5 us, sampling-capacitor settling is the real accuracy limit, so give the source impedance a buffer when driving it from a high-impedance divider.
Decide early whether the board runs the MCU directly at 5 volts or steps down to a lower rail. If the system uses a 5-volt-only rail, the S08SH family's 5-volt positioning matches it and few external components are needed; if a 3.3-volt rail is used elsewhere, budget for a regulator and check the I/O levels that cross between domains. Keep the regulator's switching node physically separated from the analog inputs and from the ADC reference path.
Compliance Information
The NXP product page lists Environmental Quality and Shipping information for this part; individual compliance declarations should be confirmed on that page for the specific ordering code and date.
