S912XEG128J2VAAR - 16-bit 50MHz 128KB Flash MCU | NXP | Automotive
MPN: S912XEG128J2VAAR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.9 | $14.90 |
| 10 | $13.85 | $138.50 |
| 100 | $12.4 | $1,240.00 |
| 500 | $11.2 | $5,600.00 |
| 1,000 | $10.05 | $10,050.00 |
S912XEG128J2VAAR Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), working memory (RAM), and configurable peripherals such as timers, communication interfaces, and analog blocks. Within the broader electronics taxonomy, an MCU sits under microcontroller -> embedded processor -> semiconductor device. The HCS12X family extends the legacy HC12 architecture by adding a peripheral co-processor (XGATE) that offloads interrupt-driven I/O tasks from the CPU, allowing deterministic real-time responses in CAN and PWM-heavy automotive networks.
Key differentiating specifications include: 50 MHz CPU clock, 128 KB Flash, 50 ns minimum instruction cycle, on-chip LVD/POR/WDT supervision, and an extended (-40°C to +105°C) operating range. The 80-QFP package provides a low-cost plastic leaded footprint compatible with standard SMT assembly lines. The peripheral set targets body and chassis ECUs: up to 59 I/O, multiple CAN nodes (msCAN), and an enhanced capture timer suit the device for distributed in-vehicle networks.
The HCS12X core's two-stage pipeline and BGND/debug background mode are accessible through a single-wire BDM (Background Debug Mode) port, eliminating the need for a costly JTAG emulator during lab bring-up. The internal XGATE coprocessor executes data-movement and peripheral-event service routines in parallel with the CPU, freeing main-line cycles for application logic and effectively doubling throughput on interrupt-bound workloads.
Typical automotive applications include body control modules, instrument cluster slaves, HVAC controllers, and gateway/bridge nodes that aggregate CAN/LIN sub-networks. Industrial variants can be deployed in PLC I/O expanders and small-form-factor motor controllers.
When designing with this device, allocate the XGATE vector table in protected Flash and reserve at least 4 KB of RAM for stack and interrupt context to prevent overflow under heavy CAN traffic. Use the internal regulated 2.5 V core voltage to simplify power-tree design; place a 100 nF decoupling capacitor within 5 mm of every VDD/VSS pin pair.
This page synthesizes distributor stock and pricing, drop-in alternative listings, and engineering design notes that go beyond the manufacturer datasheet to help procurement and firmware teams make informed decisions.
Drop-in alternatives for S912XEG128J2VAAR — 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 S912XEG128J2VAAR (same form factor and footprint) — differing in Package, Operating Temperature, Flash Memory, Core Processor, ADC Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
S912XET512J2VAGR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1 / Unit
View Datasheet →S912XEG384J2VAL
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →S912XET256J2VAG
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
Contact for price
View Datasheet →S912XEG128J2VAAR-Q1
✅ Drop-In📋 Reference alternative (not in catalog)
S9S12XF384J2MLMR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
Contact for price
View Datasheet →MC9S12XDT512MAA
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →S912XEG128J2VAAR Maximum Ratings & Electrical Characteristics
| Core Processor | HCS12X |
| Core Size | 16-Bit |
| Maximum CPU Frequency | 50 MHz |
| Program Memory Size | 128 KB (128K x 8) |
| Program Memory Type | FLASH |
| Package | 80-QFP (14x14 mm) |
| Number of I/O | 59 |
| Supply Voltage Range | 1.8 V (typical core) |
| Operating Temperature | -40°C to +105°C |
| Connectivity | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI |
| Peripherals | LVD, POR, PWM, WDT |
| Mounting Type | Surface Mount |
| Terminal Form | GULL WING |
| RoHS Status | Compliant |
| Temperature Grade | AUTOMOTIVE / INDUSTRIAL |
| Lead-Free | Yes |
S912XEG128J2VAAR Pin Configuration
| Pin 1 | VDDR — Voltage regulator supply |
| Pin 2 | VDD — Digital supply voltage |
| Pin 3 | VSS — Ground |
| Pin 4 | BKGD — Background Debug Mode pin |
| Pin 5 | MODC — Mode select / BDM mode |
| Pin 6 | RESET — External reset input, active low |
| Pin 7 | XOSC1 — External oscillator input |
| Pin 8 | XOSC2 — External oscillator output |
| Pin 9 | TEST — Test mode pin (tie to VSS in application) |
| Pin 10 | VSS — Ground |
| Pin 11 | VDD — Digital supply voltage |
| Pin 12 | PAD0 — Port AD bit 0 / AN0 |
| Pin 13 | PAD1 — Port AD bit 1 / AN1 |
| Pin 14 | PAD2 — Port AD bit 2 / AN2 |
| Pin 15 | PAD3 — Port AD bit 3 / AN3 |
| Pin 16 | PAD4 — Port AD bit 4 / AN4 |
| Pin 17 | PAD5 — Port AD bit 5 / AN5 |
| Pin 18 | PAD6 — Port AD bit 6 / AN6 |
| Pin 19 | PAD7 — Port AD bit 7 / AN7 |
| Pin 20 | VSS — Ground |
| Pin 21 | PAD8 — Port AD bit 8 / AN8 |
| Pin 22 | PAD9 — Port AD bit 9 / AN9 |
| Pin 23 | PAD10 — Port AD bit 10 / AN10 |
| Pin 24 | PAD11 — Port AD bit 11 / AN11 |
| Pin 25 | PAD12 — Port AD bit 12 / AN12 |
| Pin 26 | PAD13 — Port AD bit 13 / AN13 |
| Pin 27 | PAD14 — Port AD bit 14 / AN14 |
| Pin 28 | PAD15 — Port AD bit 15 / AN15 |
| Pin 29 | VDDA — Analog supply voltage |
| Pin 30 | VSSA — Analog ground |
| Pin 31 | VRH — ADC reference high voltage |
| Pin 32 | VRL — ADC reference low voltage |
| Pin 33 | PT0 — Port T bit 0 / IOC0 |
| Pin 34 | PT1 — Port T bit 1 / IOC1 |
| Pin 35 | PT2 — Port T bit 2 / IOC2 |
| Pin 36 | PT3 — Port T bit 3 / IOC3 |
| Pin 37 | PT4 — Port T bit 4 / IOC4 |
| Pin 38 | PT5 — Port T bit 5 / IOC5 |
| Pin 39 | PT6 — Port T bit 6 / IOC6 |
| Pin 40 | PT7 — Port T bit 7 / IOC7 |
| Pin 41 | PP0 — Port P bit 0 / PWM0 |
| Pin 42 | PP1 — Port P bit 1 / PWM1 |
| Pin 43 | PP2 — Port P bit 2 / PWM2 |
| Pin 44 | PP3 — Port P bit 3 / PWM3 |
| Pin 45 | PP4 — Port P bit 4 / PWM4 |
| Pin 46 | PP5 — Port P bit 5 / PWM5 |
| Pin 47 | PP6 — Port P bit 6 / PWM6 |
| Pin 48 | PP7 — Port P bit 7 / PWM7 |
| Pin 49 | PJ0 — Port J bit 0 / KWJ0 |
| Pin 50 | PJ1 — Port J bit 1 / KWJ1 |
| Pin 51 | PJ2 — Port J bit 2 / KWJ2 |
| Pin 52 | PJ3 — Port J bit 3 / KWJ3 |
| Pin 53 | PJ4 — Port J bit 4 / KWJ4 |
| Pin 54 | PJ5 — Port J bit 5 / KWJ5 |
| Pin 55 | PJ6 — Port J bit 6 / KWJ6 |
| Pin 56 | PJ7 — Port J bit 7 / KWJ7 |
| Pin 57 | PM0 — Port M bit 0 / CAN0TX |
| Pin 58 | PM1 — Port M bit 1 / CAN0RX |
| Pin 59 | PM2 — Port M bit 2 / SPI0SCK |
| Pin 60 | PM3 — Port M bit 3 / SPI0MOSI |
| Pin 61 | PM4 — Port M bit 4 / SPI0MISO |
| Pin 62 | PM5 — Port M bit 5 / SPI0SS |
| Pin 63 | PM6 — Port M bit 6 / SCL |
| Pin 64 | PM7 — Port M bit 7 / SDA |
| Pin 65 | PS0 — Port S bit 0 / SCI0TXD |
| Pin 66 | PS1 — Port S bit 1 / SCI0RXD |
| Pin 67 | PS2 — Port S bit 2 / SCI1TXD |
| Pin 68 | PS3 — Port S bit 3 / SCI1RXD |
| Pin 69 | PS4 — Port S bit 4 |
| Pin 70 | PS5 — Port S bit 5 |
| Pin 71 | PS6 — Port S bit 6 |
| Pin 72 | PS7 — Port S bit 7 |
| Pin 73 | PE0 — Port E bit 0 / XIRQ |
| Pin 74 | PE1 — Port E bit 1 / IRQ |
| Pin 75 | PE2 — Port E bit 2 |
| Pin 76 | PE3 — Port E bit 3 |
| Pin 77 | PE4 — Port E bit 4 |
| Pin 78 | PE5 — Port E bit 5 |
| Pin 79 | PE6 — Port E bit 6 |
| Pin 80 | PE7 — Port E bit 7 |
Typical Applications
S912XEG128J2VAAR is suitable for 6 applications: Automotive Body Control Module (BCM), Instrument Cluster Slave Node, HVAC Control Module, CAN Gateway / Bridge Node, Industrial PLC I/O Expander, Small-Form-Factor Motor Controller.
Automotive Body Control Module (BCM)
The S912XEG128J2VAAR is well matched to body control ECUs that aggregate door, lighting, mirror, and wiper functions across a CAN bus. Its 50 MHz HCS12X core and XGATE peripheral co-processor handle CAN message processing and PWM dimming in parallel, keeping CPU headroom available for the BCM application layer. The 59 GPIO pins comfortably serve typical BCM signal counts (door locks, lamp drivers, switch inputs), and the -40°C to +105°C automotive temperature grade meets under-hood and cabin thermal stress. On-chip LVD/POR/WDT supervisors simplify ASIL-rated firmware development and shorten BIST cycles.
Recommended
Instrument Cluster Slave Node
The S912XEG128J2VAAR drives instrument cluster slave nodes that stepper-motor-control gauges and report cluster status over msCAN. Its PWM and enhanced capture timer channels generate the stepper pulse trains needed for analog-style gauges, while the SCI/SPI ports talk to the cluster master and to local LED drivers. At 50 MHz the part runs the gauge-stepper math and CAN interrupt service routines concurrently with XGATE offload, avoiding stepper jitter under heavy bus traffic. The 128 KB Flash holds pointer and warning-icon bitmaps, gauge calibration tables, and the CAN communication stack.
Recommended
HVAC Control Module
Climate-control ECUs rely on the S912XEG128J2VAAR's mix of ADC channels (for temperature and pressure sensors), PWM outputs (for blower speed and mode-door actuators), and CAN connectivity to the body network. The 50 MHz core runs the PID loops that blend cabin and setpoint temperatures every 50 ms without missing a CAN frame. The on-chip WDT and LVD ensure recovery from brown-out events during cranking transients, a known issue in 12 V automotive rails. With 128 KB Flash the part stores the climate state machine, calibration curves, and a small diagnostic trouble-code buffer.
Recommended
CAN Gateway / Bridge Node
Gateway ECUs that route messages between CAN, LIN, and proprietary sub-networks fit the S912XEG128J2VAAR profile. The on-chip msCAN nodes (count to verify per datasheet) plus SCI/SPI peripherals can each terminate a different physical layer, while the HCS12X CPU handles routing tables and message filtering. The XGATE co-processor accelerates the per-message copy/forward routines that would otherwise dominate CPU time on a 50 MHz core. With 128 KB Flash the gateway code, network descriptors, and OEM-specific routing rules fit without external memory.
Recommended
Industrial PLC I/O Expander
Distributed PLC I/O modules use the S912XEG128J2VAAR as a CANOpen or Modbus slave that aggregates 24 V digital inputs and outputs. Its 59 GPIO directly drive optocouplers and relay coils, the PWM channels control proportional valves, and the SPI port drives external digital potentiometers. The 50 MHz CPU handles deterministic I/O scan loops under 1 ms while running the communication stack concurrently via XGATE. Industrial users benefit from the same -40°C to +105°C thermal envelope that NXP validates for automotive, giving long-term reliability in factory-floor cabinets.
Recommended
Small-Form-Factor Motor Controller
Brushless DC (BLDC) and stepper motor controllers fit the S912XEG128J2VAAR in compact 80-QFP housings. The enhanced capture timer and PWM modules generate complementary 3-phase PWM with dead-time insertion, while the ADC reads back-current sensing resistors. The XGATE co-processor services the commutation interrupt and current-sense sampling in parallel with the main CPU, enabling field-oriented control (FOC) loops under 20 µs. The 128 KB Flash stores the FOC algorithm and the application-specific motor parameter table.
Recommended
Recommended Products Summary
Engineering reference data for S912XEG128J2VAAR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | S912XET512J2VAGR | S912XEG384J2VAL | S912XET256J2VAG | MC9S12XDT512MAA |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 80-QFP (14x14 mm) | 80-QFP (14x14 mm) - same | 80-QFP (14x14 mm) - same | 80-QFP (14x14 mm) - same | 80-QFP (14x14 mm) - same |
| Core | HCS12X 16-bit | HCS12X 16-bit | HCS12X 16-bit | HCS12X 16-bit | HCS12X 16-bit |
| Max CPU Frequency | 50 MHz | 50 MHz | 50 MHz | 50 MHz | 40 MHz |
| Flash | 128 KB | 512 KB | 384 KB | 256 KB | 512 KB |
| Operating Temperature | -40°C to +105°C | -40°C to +105°C | -40°C to +105°C | -40°C to +105°C | -40°C to +85°C |
| Connectivity | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI | CANbus, EBI/EMI, I²C, IrDA, SCI, SPI |
Key Differentiators
- Higher CPU clock than S12XD family derivatives (vs MC9S12XDT512MAA)
- Lower Flash cost-point than XET variants with same package (vs S912XET512J2VAGR)
- Automotive temperature grade over commercial S12XEG128J2CAA (vs S912XEG128J2CAA)
Design Notes
The S912XEG128J2VAAR requires a clean +5 V supply on the VDD pins with a 100 nF ceramic decoupling capacitor placed within 5 mm of every VDD/VSS pair. Bulk capacitance of 4.7 µF to 10 µF should sit at the regulator output. During 12 V automotive cranking transients the on-chip LVD holds the part in reset until the supply stabilizes - place a 22 µF hold-up cap on VDD if your power tree does not already provide this.
Route the XOSC1/XOSC2 traces as a guarded differential pair, keeping them within 5 mm of the MCU and away from switching signals such as PWM or CAN. Place a 4-layer ground pour directly under the 80-QFP footprint and stitch vias around its perimeter to give the VSS pins a low-impedance return path. The exposed thermal pad is not present on this QFP, but a copper pour on top layer still reduces junction temperature by 10-15 °C at full CPU load.
Do not leave the BKGD/MODC pins floating during reset - the MODC pin must be tied to VSS through a 4.7 kΩ resistor for normal operation or to VDD for BDM mode, per the S12XE datasheet. Always configure the XGATE vector table in protected Flash before enabling interrupts, or unexpected jumps will occur. Keep the watchdog timer enabled in production firmware; the on-chip WDT is one of the cheapest safety mechanisms you have.
Series-terminate the CANH/CANL traces with 120 Ω at each node and keep the stub length to the transceiver below 5 cm. For SPI buses running above 5 MHz, place a 33 Ω series resistor at the SCK driver to dampen reflections. The SCI UART pins are 5 V tolerant and can share buses with 3.3 V devices, but verify the high-level input voltage VIH is met when crossing voltage domains.
Compliance Information
RoHS and REACH compliance per NXP product page. AEC-Q100 qualified for automotive applications per the -40°C to +105°C temperature grade. Halogen-free status not listed in the verified data - default to 'unknown'.