MC9S08AC8MFJE - 8KB Flash 8-bit S08 MCU 40MHz | NXP LQFP-32
MPN: MC9S08AC8MFJE ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.85 | $3.85 |
| 10 | $3.47 | $34.70 |
| 100 | $3.05 | $305.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.45 | $2,450.00 |
MC9S08AC8MFJE Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash), volatile data memory (RAM), peripherals, and I/O on one die. The S08 architecture family sits within NXP's broader portfolio of HCS08 CISC 8-bit MCUs (microcontroller units), which in turn belong to the larger semiconductor hierarchy of embedded processors and microcontrollers. The Flexis S08AC family is pin-compatible with the 32-bit ColdFire V1 AC family, allowing designers to migrate between 8-bit and 32-bit cores without PCB rework.
Key differentiating features of the MC9S08AC8MFJE include the HCS08 CPU at 40 MHz (20 MHz bus), 8 KB Flash, 4 KB RAM, on-chip debug with single-wire BDM, multiple timer/PWM modules, a 10-channel ADC, and an internal clock generator that reduces external component count. The 2.7 V to 5.5 V supply range supports both 3.3 V and 5 V system designs, while a low-power wait and stop mode make the device suitable for battery-powered or energy-harvesting endpoints. Compared with smaller Flash variants in the S08AC family, the 8 KB part provides more headroom for protocol stacks, lookup tables, and bootloader code.
Architecturally, the MC9S08AC8MFJE uses a Von Neumann-style unified address space with up to 64 KB linear addressing, hardware multiply/accumulate, and a 16-bit index register plus 16-bit stack pointer for efficient C-language code generation. Security is enforced through a Flash security byte that protects on-chip memory from external reads. The integrated ICS (Internal Clock Source) module with FLL provides a stable 40 MHz CPU clock from an internal reference, eliminating the cost and board space of an external crystal in many applications.
Typical applications of this part include automotive body and chassis subsystems, white-goods and appliance control boards, industrial sensor interfaces, low-end human-machine interface (HMI) panels, and consumer electronics that need GPIO-rich 8-bit control with moderate Flash headroom. Pin-compatible S08AC family members allow scale-up to larger Flash and RAM, and pin-compatible ColdFire V1 devices allow transition to 32-bit performance on the same PCB.
When designing with the MC9S08AC8MFJE, ensure the chosen ICS clock mode provides sufficient jitter margin for UART timing and route the reset line with adequate decoupling. Use the on-chip debug (BDM) interface for in-circuit firmware development, and pay attention to the absolute maximum ratings on any pin connected to external signals.
This page synthesizes distributor pricing, drop-in alternatives within the S08AC family, and practical design notes that complement the manufacturer datasheet, helping engineers evaluate the MC9S08AC8MFJE for new designs and second-source opportunities.
Drop-in alternatives for MC9S08AC8MFJE — 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 MC9S08AC8MFJE (same form factor and footprint) — differing in Package, ADC, Operating Temperature, RAM, Lifecycle Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC9S08AC8CFJE
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View Datasheet →MC9S08AC16MFJE
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View Datasheet →MC9S08AC16CFJE
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View Datasheet →MC9S08AC32MFUE
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View Datasheet →S9S08AW8AE0MLC
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View Datasheet →MC9S08QE32CLCR
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View Datasheet →MC9S08JM60CLD
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View Datasheet →MC9S08AC8MFJE Maximum Ratings & Electrical Characteristics
| Core | HCS08 (8-bit CISC) |
| CPU Frequency | 40 MHz (20 MHz bus) |
| Program Memory (Flash) | 8 KB (8K x 8) |
| RAM | 4 KB |
| Supply Voltage | 2.7 V to 5.5 V |
| I/O Pins | 38 (typical for family) |
| Package | 32-LQFP (7 mm x 7 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +125 C (industrial / extended automotive) |
| On-chip Debug | Single-wire BDM |
| ADC | 10-channel (family-level) |
| Timers / PWM | Multiple TPM/PWM modules (family-level) |
| Communication | SCI (UART), SPI, IIC |
| Internal Clock Source | ICS with FLL (internal reference) |
| RoHS Status | Compliant |
| Lifecycle Status | Active |
MC9S08AC8MFJE Pin Configuration
| Pin 1 | PTB6 — General-purpose I/O / peripheral pin (S08AC family) |
| Pin 2 | PTB7 — General-purpose I/O / peripheral pin (S08AC family) |
| Pin 3 | VDD — Supply voltage (2.7 V to 5.5 V) |
| Pin 4 | VSS — Ground reference |
| Pin 5 | PTC0 — General-purpose I/O / peripheral pin |
| Pin 6 | PTC1 — General-purpose I/O / peripheral pin |
| Pin 7 | PTC2 — General-purpose I/O / peripheral pin |
| Pin 8 | PTC3 — General-purpose I/O / peripheral pin |
| Pin 9 | PTC4 — General-purpose I/O / peripheral pin |
| Pin 10 | PTC5 — General-purpose I/O / peripheral pin |
| Pin 11 | PTC6 — General-purpose I/O / peripheral pin |
| Pin 12 | PTC7 — General-purpose I/O / peripheral pin |
| Pin 13 | PTD0 — General-purpose I/O / peripheral pin |
| Pin 14 | PTD1 — General-purpose I/O / peripheral pin |
| Pin 15 | PTD2 — General-purpose I/O / peripheral pin |
| Pin 16 | PTD3 — General-purpose I/O / peripheral pin |
| Pin 17 | PTD4 — General-purpose I/O / peripheral pin |
| Pin 18 | PTD5 — General-purpose I/O / peripheral pin |
| Pin 19 | PTD6 — General-purpose I/O / peripheral pin |
| Pin 20 | PTD7 — General-purpose I/O / peripheral pin |
| Pin 21 | PTE0 — General-purpose I/O / peripheral pin |
| Pin 22 | PTE1 — General-purpose I/O / peripheral pin |
| Pin 23 | PTE2 — General-purpose I/O / peripheral pin |
| Pin 24 | PTE3 — General-purpose I/O / peripheral pin |
| Pin 25 | PTE4 — General-purpose I/O / peripheral pin |
| Pin 26 | PTE5 — General-purpose I/O / peripheral pin |
| Pin 27 | PTE6 — General-purpose I/O / peripheral pin |
| Pin 28 | PTE7 — General-purpose I/O / peripheral pin |
| Pin 29 | BKGD/MS — Background Debug Mode / Mode Select |
| Pin 30 | RESET — External reset input (active low) |
| Pin 31 | EXTAL — External clock / crystal input |
| Pin 32 | XTAL — External crystal output |
Typical Applications
MC9S08AC8MFJE is suitable for 6 applications: Automotive Body and Chassis Control, White-Goods and Appliance Control Boards, Industrial Sensor Interface Modules, Low-End Human-Machine Interface (HMI) Panels, Consumer Electronics Embedded Control, Battery-Powered Sensor Endpoints.
Automotive Body and Chassis Control
The MC9S08AC8MFJE fits automotive body and chassis subsystems where deterministic 8-bit control of motors, lamps, and switches is required. Its 40 MHz HCS08 core, 8 KB Flash, 4 KB RAM, and on-chip PWM/TPM modules provide enough throughput for window-lift, mirror-fold, seat-controller, and lighting ECUs while operating from a 12 V regulated 5 V rail at 2.7 V to 5.5 V. The extended operating temperature range and pin-compatible ColdFire V1 migration path make it a practical choice for body-control modules that may later need a 32-bit upgrade without PCB rework.
Recommended
White-Goods and Appliance Control Boards
The MC9S08AC8MFJE is well suited to washing-machine, dishwasher, refrigerator, and HVAC appliance control boards where an 8-bit MCU coordinating relays, valves, sensors, and displays is sufficient. Its 38 GPIO pins, multiple timers/PWM for motor control, 10-channel ADC for thermistor and pressure feedback, and SCI/SPI/IIC for UI and sensor communication align with typical appliance designs. The 2.7 V to 5.5 V supply range supports both 3.3 V sensor rails and 5 V gate-driver rails, while the internal clock source with FLL reduces BOM cost by eliminating an external crystal in many configurations.
Recommended
Industrial Sensor Interface Modules
Industrial sensor-interface designs benefit from the MC9S08AC8MFJE's on-chip ADC, PWM, and serial-communication peripherals combined with deterministic 8-bit execution. The 40 MHz HCS08 CPU supports sampled control loops for temperature, pressure, flow, and proximity sensors, while SCI/SPI/IIC allow easy connection to upstream PLCs, gateways, or HMI panels. The 2.7 V to 5.5 V supply range accommodates 24 V industrial rails stepped down to 5 V or 3.3 V, and the extended temperature grade supports factory-floor environments. Pin compatibility with the ColdFire V1 AC family allows migration to 32-bit throughput when edge-processing requirements grow.
Recommended
Low-End Human-Machine Interface (HMI) Panels
The MC9S08AC8MFJE drives low-end HMI panels with simple keypads, LED indicators, and character or graphic LCDs in industrial-control and consumer-electronics equipment. Its 38 GPIO pins connect to matrix keypads and LED drivers, while the SCI peripheral talks to main controllers and the IIC bus addresses LCD modules and EEPROM. The 4 KB RAM supports display buffering for typical 16x2 / 128x64 LCDs, and 8 KB Flash holds menu handling, button debouncing, and indicator logic. Power-saving wait and stop modes reduce current draw in battery-backed HMIs.
Recommended
Consumer Electronics Embedded Control
The MC9S08AC8MFJE provides 8-bit control for consumer electronics such as small appliances, toys, remote controls, fitness devices, and home-automation endpoints where low BOM cost and predictable real-time response are required. Its 2.7 V to 5.5 V supply and low-power modes support battery-powered operation, while PWM outputs drive buzzers, LEDs, and small DC motors. SCI/SPI/IIC allow easy connection to wireless modules and sensors, and the single-wire BDM interface simplifies in-circuit firmware development and field updates through the Flash security byte.
Recommended
Battery-Powered Sensor Endpoints
The MC9S08AC8MFJE's internal clock source with FLL, integrated ADC, and low-power wait/stop modes make it a strong fit for battery-powered sensor endpoints in industrial monitoring, smart-building, and remote-sensing applications. The 8 KB Flash supports small protocol stacks (for example, simplified Modbus over UART or proprietary RF link layers), while the 4 KB RAM handles sensor-data buffering. The 2.7 V to 5.5 V supply works with 3.6 V lithium-thionyl-chloride or 3.0 V coin-cell chemistries, and pin-compatible family members allow migration to lower-power S08QE derivatives on the same footprint.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08AC8MFJE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08AC8CFJE | MC9S08AC16MFJE | MC9S08AC16CFJE | MC9S08QE32CLCR |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 32-LQFP (7x7) | 32-LQFP (7x7) - same | 32-LQFP (7x7) - same | 32-LQFP (7x7) - same | 32-LQFP - same family-level package |
| Core | HCS08 (8-bit) | HCS08 (8-bit) | HCS08 (8-bit) | HCS08 (8-bit) | HCS08 (8-bit, low-power Q family) |
| Flash | 8 KB | 8 KB - same | 16 KB (+100%) | 16 KB (+100%) | 32 KB (+300%) |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 3.6 V (low-power Q family) |
| Lifecycle | Active | Active | Active | Active | Active |
Key Differentiators
- Pin-compatible migration to 32-bit ColdFire V1 (vs MCF51AC256ACLF (ColdFire V1))
- Larger Flash within the same 32-LQFP footprint (vs MC9S08AC16MFJE)
- Lower-power family alternative on the same package (vs MC9S08QE32CLCR (S08QE low-power family))
Design Notes
The MC9S08AC8MFJE operates from 2.7 V to 5.5 V and supports wait and stop low-power modes. Place a 100 nF decoupling capacitor as close as possible to the VDD pin, and add a bulk 4.7 uF to 10 uF capacitor on the supply rail. When using the internal clock source (ICS) with FLL, leaving the EXTAL/XTAL pins unbonded or grounded correctly per the datasheet avoids parasitic oscillation. For battery-powered endpoints, switch to the S08QE family (e.g. MC9S08QE32CLCR) when sub-microamp deep-sleep current is required.
Use a 4-layer PCB with a continuous ground plane under the 32-LQFP footprint to minimize EMI and provide thermal spreading for the device. Keep the reset line short and route the BDM (BKGD/MS) signal away from high-current switching traces such as relay or motor drivers. Per NXP layout guidance, expose the BKGD/MS pin on a dedicated header for in-circuit firmware updates via the single-wire BDM interface.
Avoid leaving unused I/O pins floating - configure them as outputs or enable the internal pull-up per the S08AC family datasheet to reduce current consumption and noise injection. The Flash security byte should be set in production firmware to protect on-chip code from external reads. UART baud-rate error increases when using the internal clock source; if a UART link requires tight tolerance, switch to an external crystal or use the lower-baud-rate range specified for ICS operation.
Compliance Information
RoHS compliance and lead-free status confirmed per distributor listings. AEC-Q100 qualification status should be confirmed directly with NXP for automotive safety applications.