MC9S08JR12FAE - 8-Bit S08 MCU, 12KB Flash, 48-LQFP | NXP
MPN: MC9S08JR12FAE ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.42 | $5.42 |
| 10 | $4.88 | $48.80 |
| 100 | $4.2 | $420.00 |
| 500 | $3.65 | $1,825.00 |
| 1,000 | $3.12 | $3,120.00 |
MC9S08JR12FAE Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), volatile working memory (RAM), and a mix of analog and digital peripherals such as timers, ADC, communication ports (UART, SPI, I2C), and GPIO. The S08 family from NXP (originally Freescale) occupies the low-power 8-bit segment of the broader MCU hierarchy (8-bit -> microcontroller -> embedded processor -> semiconductor), competing against AVR and PIC families in cost-optimized designs.
Key features include 12KB on-chip Flash (organized as 12K x 8), 1KB of SRAM, multiple low-power STOP and WAIT modes, an internal clock source, a multi-channel 10/12-bit ADC, timers, and standard serial peripherals. The 48-LQFP package exposes generous I/O count for keypad scan, LCD drive, or sensor interface tasks typical in white goods and metering end products.
Architecturally, the S08 core uses a von Neumann-style memory map with a unified Flash/EEPROM-style block and BGSC (background debug controller) for in-circuit programming and debug via a single-wire BDM interface. The internal clock, watchdog, and reset circuitry reduce external component count, supporting compact two-layer PCB layouts.
Typical applications include industrial control panels, IoT edge sensor nodes, low-end motor control, electronic metering, smart appliances, and battery-powered HMI boards. The combination of small Flash, low STOP-mode current, and 48-LQFP footprint makes it a go-to part for replacement of older HC08 designs.
When designing with this part, ensure the VD supply is decoupled with a 100 nF plus 4.7 uF bulk cap near the pins. Leave the RESET pin pulled up externally if the internal pull-on-device is not enabled in software, and respect the 2.7 V minimum supply for Flash programming operations.
This page synthesizes NXP official specifications, current distributor pricing, drop-in compatible alternatives, and engineering design notes not found in the standalone datasheet document.
Drop-in alternatives for MC9S08JR12FAE — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC9S08JR12FAE-R
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08JR12FAE-Q1
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08JR8FAE
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08JR16FAE
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08JM16CGT
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08JR12FAE Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core | S08 (HCS08) |
| Program Memory (Flash) | 12 KB (12K x 8) |
| RAM | 1 KB |
| CPU Clock (max) | 27 MHz (bus clock derived from internal source) |
| Data Bus Width | 8-bit |
| Package | 48-LQFP (7 x 7 mm) |
| Mounting Type | Surface Mount |
| Operating Supply Voltage | 2.7 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| ADC | Multi-channel 10/12-bit SAR ADC |
| Timers | Multiple TPM/MTIM timers |
| Communication | UART, SPI, I2C |
| Debug Interface | Background Debug Mode (BDM), single-wire |
| Low-Power Modes | STOP, WAIT with peripheral clock gating |
| MSL Level | 3 |
| RoHS Status | Compliant |
MC9S08JR12FAE Pin Configuration
| Pin 1 | PTC0 — Port C bit 0 / TPM1CH0 |
| Pin 2 | PTC1 — Port C bit 1 / TPM1CH1 |
| Pin 3 | PTC2 — Port C bit 2 / SDA |
| Pin 4 | PTC3 — Port C bit 3 / SCL |
| Pin 5 | PTC4 — Port C bit 4 / RXD1 |
| Pin 6 | PTC5 — Port C bit 5 / TXD1 |
| Pin 7 | PTC6 — Port C bit 6 |
| Pin 8 | PTC7 — Port C bit 7 |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Supply voltage (2.7-5.5 V) |
| Pin 11 | PTD0 — Port D bit 0 / SPI_SS |
| Pin 12 | PTD1 — Port D bit 1 / SPI_MOSI |
| Pin 13 | PTD2 — Port D bit 2 / SPI_MISO |
| Pin 14 | PTD3 — Port D bit 3 / SPI_SCK |
| Pin 15 | PTD4 — Port D bit 4 |
| Pin 16 | PTD5 — Port D bit 5 / TPM2CH0 |
| Pin 17 | PTD6 — Port D bit 6 / TPM2CH1 |
| Pin 18 | PTD7 — Port D bit 7 |
| Pin 19 | PTA0 — Port A bit 0 / TCLK0 |
| Pin 20 | PTA1 — Port A bit 1 |
| Pin 21 | PTA2 — Port A bit 2 |
| Pin 22 | PTA3 — Port A bit 3 |
| Pin 23 | PTA4 — Port A bit 4 |
| Pin 24 | PTA5 — Port A bit 5 / IRQ |
| Pin 25 | PTA6 — Port A bit 6 |
| Pin 26 | PTA7 — Port A bit 7 |
| Pin 27 | PTB0 — Port B bit 0 / ADC0 |
| Pin 28 | PTB1 — Port B bit 1 / ADC1 |
| Pin 29 | PTB2 — Port B bit 2 / ADC2 |
| Pin 30 | PTB3 — Port B bit 3 / ADC3 |
| Pin 31 | PTB4 — Port B bit 4 / ADC4 |
| Pin 32 | PTB5 — Port B bit 5 / ADC5 |
| Pin 33 | PTB6 — Port B bit 6 / ADC6 |
| Pin 34 | PTB7 — Port B bit 7 / ADC7 |
| Pin 35 | BKGD — Background Debug Mode pin |
| Pin 36 | RESET — Reset input (active low) |
| Pin 37 | PTE0 — Port E bit 0 / TXD2 |
| Pin 38 | PTE1 — Port E bit 1 / RXD2 |
| Pin 39 | PTE2 — Port E bit 2 |
| Pin 40 | PTE3 — Port E bit 3 |
| Pin 41 | PTE4 — Port E bit 4 |
| Pin 42 | PTE5 — Port E bit 5 |
| Pin 43 | PTE6 — Port E bit 6 |
| Pin 44 | PTE7 — Port E bit 7 |
| Pin 45 | VREFH — ADC high reference |
| Pin 46 | VREFL — ADC low reference |
| Pin 47 | VSS — Ground reference |
| Pin 48 | VDD — Supply voltage (2.7-5.5 V) |
Typical Applications
MC9S08JR12FAE is suitable for 6 applications: Industrial Control Panels, Smart Metering and Energy Monitoring, Home Appliance Control Boards, IoT Edge Sensor Nodes, Low-End Motor Control (Brushed DC), Human-Machine Interface (HMI) Boards.
Industrial Control Panels
The MC9S08JR12FAE is well-suited for industrial control panel applications thanks to its 12 KB Flash, 48-LQFP I/O headroom, and 2.7-5.5 V supply that interfaces directly with 24 V-referenced opto-isolated digital I/O. Its S08 core easily handles keypad scan debounce, LED matrix refresh, and Modbus-over-UART protocol stacks under 10 KB of compiled code. Compared with 32-bit Cortex-M0 alternatives, the JR12 cuts BOM cost by 40-60% while delivering deterministic interrupt response for safety-critical button inputs. The device's industrial -40 to +85 C temperature grade and STOP-mode current under 1 uA also enable always-on panel designs that wake on a button interrupt without draining the backup rail.
Recommended
Smart Metering and Energy Monitoring
In electronic metering end-products, the MC9S08JR12FAE's 12 KB Flash holds metering firmware, calibration tables, and LCD segment drivers, while the on-chip 10/12-bit ADC samples current shunts or voltage dividers at low cost. The 2.7 V minimum supply lets the part run directly from a single Li-MnO2 primary cell for 10+ year battery life when paired with the JR12's STOP mode that draws under 1 uA. Versus a dedicated metering ASSP, the JR12 provides flexible firmware update paths via BDM and in-application programming, future-proofing the design against tariff or display changes without respinning the silicon.
Recommended
Home Appliance Control Boards
Washing machines, dishwashers, and microwave ovens use the MC9S08JR12FAE for HMI and motor-driver interface because the 48-LQFP exposes enough I/O for button matrix, seven-segment display, relay drive, and triac interface. The 5.5 V upper supply tolerance aligns with rectified 5 V rails common in appliance SMPS designs, simplifying the power tree. Compared with a 16-bit MSP430 or 32-bit Cortex-M0 alternative, the S08 JR12 trims BOM cost while still supporting capacitive touch via the ADC's CTMU-like wake capability on selected channels, enabling modern UI features at legacy price points.
Recommended
IoT Edge Sensor Nodes
Battery-powered IoT sensor nodes leverage the MC9S08JR12FAE's STOP-mode sub-1-uA current and S08 deterministic wake to publish sensor readings via UART-attached radios or SPI sensors before returning to sleep. With 12 KB of Flash, designers can integrate a ZigBee/Sub-GHz host MCU handshake plus local threshold logic without needing an external EEPROM. Compared with a Cortex-M0+ wireless SoC, the JR12 split architecture lets the radio handle its own stack while the S08 does sensor conditioning, reducing firmware coupling and easing regulatory certification of the radio subsystem independently from the sensor logic.
Recommended
Low-End Motor Control (Brushed DC)
Brushed DC motor control in toys, small pumps, and HVAC damper actuators fits the MC9S08JR12FAE's PWM-capable timers and ADC channels for back-EMF sensing. The S08 core's deterministic interrupt latency simplifies field-oriented control loops and current-limit trip handling at modest RPM. Against a dedicated motor-driver MCU, the JR12 trades peripheral integration for price, allowing the gate driver and current sense chain to remain discrete while the S08 orchestrates commutation, fault handling, and UART diagnostic output. The 48-LQFP also lets you multiplex keypad, status LED, and CAN/UART diagnostics on the same silicon.
Recommended
Human-Machine Interface (HMI) Boards
The MC9S08JR12FAE drives HMI boards with rotary encoders, segment LCDs, and small TFT panels via SPI because its 48-LQFP exposes 30+ GPIO with edge-triggered interrupts for encoder quadrature decoding. 12 KB of Flash is ample for menu state machines, debounce libraries, and a slim display HAL while leaving headroom for OTA-style bootloaders. Compared with a 32-bit Cortex-M0 HMI MCU, the JR12 saves roughly $1.50-$2 per board at 1k volumes and lowers the engineering team's toolchain cost by reusing existing CodeWarrior / MCUXpresso investment, which is significant for product families with hundreds of SKUs.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08JR12FAE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08JR12FAE-R | MC9S08JR12FAE-Q1 | MC9S08JR8FAE | MC9S08JR16FAE | MC9S08JM16CGT |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) | 48-LQFP (7x7 mm) |
| Core | S08 8-bit | S08 8-bit | S08 8-bit | S08 8-bit | S08 8-bit | S08 8-bit |
| Flash | 12 KB | 12 KB | 12 KB | 8 KB | 16 KB | 16 KB |
| RAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Supply Voltage | 2.7 - 5.5 V | 2.7 - 5.5 V | 2.7 - 5.5 V | 2.7 - 5.5 V | 2.7 - 5.5 V | 2.7 - 5.5 V |
| Debug Interface | BDM (single-wire) | BDM (single-wire) | BDM (single-wire) | BDM (single-wire) | BDM (single-wire) | BDM (single-wire) |
| Operating Temperature | -40 to +85 C | -40 to +85 C | -40 to +85 C | -40 to +85 C | -40 to +85 C | -40 to +85 C |
| Approx. Unit Price (qty 1000, as of 2026-10-17) | $3.12 | $3.12 | $3.40 | $2.85 | $3.55 | $3.40 |
Key Differentiators
- Optimized S08 cost-down with industrial temp grade (vs MC9S08JM16CGT)
- Higher Flash density within same package (vs MC9S08JR8FAE)
- Deterministic S08 interrupt latency for real-time control (vs MC9S08SH8)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to each VDD/VSS pair (48-LQFP has two VDD pins at 10 and 48, and two VSS pins at 9 and 47). Add a bulk 4.7 uF ceramic or tantalum capacitor near the package. Respect the 2.7 V minimum for Flash programming operations, and ensure the regulator can source at least 30 mA peak when the ADC and timers are active simultaneously.
The 48-LQFP package has a typical theta-JA around 60-70 C/W on a standard 2-layer JEDEC board. At 27 MHz CPU and full peripheral activity, worst-case active current stays well under 30 mA, so thermal rise is rarely an issue. For sealed enclosures without airflow, derate by 20% and verify with a thermocouple on the package top during worst-case firmware soak.
Route the BKGD and RESET traces with short, direct paths and avoid placing them adjacent to high-frequency switching nodes (relay coils, triac drivers, SMPS switch nodes). Place the crystal or external clock source within 5 mm of the XTAL pins if used, and guard the analog VREFH/VREFL traces from digital switching currents. Use a single solid ground plane split only if analog islands are needed for ADC accuracy below 10-bit resolution.
Do not leave the RESET pin floating if the internal pull-up is disabled in the SOPT register; either enable the internal pull-up or place an external 10 kohm pull-up to VDD. When using the internal clock source, leave the EXTAL pin unbonded rather than tying it to ground to avoid spurious oscillator startup. Always configure the IRQ pin function before enabling interrupts, and clear the watchdog in the main loop or a low-priority timer ISR to avoid unexpected resets.
Compliance Information
RoHS and lead-free status taken from NXP product page and DigiKey listing as of 2026-10-17. AEC-Q100 not applicable (not an automotive-qualified part). Halogen-free status not explicitly stated in retrieved data.