MC9S12XET256MAA - 16-bit 50MHz 256KB Flash MCU | NXP
MPN: MC9S12XET256MAA ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.66 | $8.66 |
| 10 | $8.23 | $82.30 |
| 100 | $7.79 | $779.00 |
| 500 | $7.4 | $3,700.00 |
| 1,000 | $6.98 | $6,980.00 |
MC9S12XET256MAA Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, memory, and peripherals such as timers, communication interfaces, and analog-to-digital converters. Within the power management and embedded control hierarchy, the MC9S12XE family sits in NXP's HCS12X line of automotive and industrial MCUs, descended from the widely used HC12/S12 architecture and enhanced with the XGATE co-processor for offloading interrupt-driven tasks from the main CPU.
Key features of the MC9S12XET256MAA include the enhanced HCS12X core with CISC instruction set at 50 MHz bus-compatible operation, 256 KB of flash program memory for substantial application code, an 8-channel 12-bit ADC for accurate analog acquisition, and 59 general-purpose I/O pins. The XGATE co-processor enables independent peripheral servicing, improving real-time performance without raising the main clock.
Technically, the S12XE family integrates the Enhanced Capture Timer, multiple serial interfaces (SCI, SPI, CAN via MSCAN modules typical of the family), a CRG clock and reset generator, and low-voltage detection. The 5 V supply domain provides the noise robustness that made the S12 platform a staple in automotive body electronics and industrial control, and the -40C to +125C operating range supports under-hood and harsh-environment deployments.
Typical applications include automotive body control modules, instrument clusters, HVAC control, industrial automation controllers, motor control panels, and building management systems. The combination of flash density, robust 5 V I/O, and CAN connectivity fits distributed networked control nodes.
Design consideration: budget the flash for bootloader and calibration data early, and use the XGATE to offload time-critical ISR work to keep main-core timing deterministic.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for MC9S12XET256MAA — 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 MC9S12XET256MAA (same form factor and footprint) — differing in Package, Core Processor, Operating Temperature, Flash Memory, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
S912XET256J2VAG
✅ Drop-In✓ In Stock
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View Datasheet →MC9S12XDT256MAA
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →MC9S12XDT512MAA
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →S912XET512J2VAGR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1 / Unit
View Datasheet →MC9S12XA256CAAR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$9.95 / Unit
View Datasheet →MC9S12XET256MAA Maximum Ratings & Electrical Characteristics
| Core Processor | HCS12X (16-bit CISC) |
| Core Size | 16-bit |
| Maximum Clock Frequency | 50 MHz |
| Flash Memory | 256 KB (256K x 8) |
| RAM | 16 KB |
| EEPROM | 4 KB |
| ADC Resolution | 12-bit |
| ADC Channels | 8 channels |
| GPIO Count | 59 |
| Supply Voltage | 5 V (core supports 1.8 V / 2.8 V / 5 V domains per family docs) |
| Operating Temperature | -40C to +125C |
| Package | 80-QFP (14 x 14 mm), PQFP |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Series | HCS12X, S12XE family |
| Co-processor | XGATE (per S12XE family architecture) |
| Program Memory Type | FLASH |
MC9S12XET256MAA 80-qfp (14 x 14 mm), pqfp Pin Configuration Guide
Pin configuration for MC9S12XET256MAA (80-qfp (14 x 14 mm), pqfp 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 MC9S12XET256MAA.
Refer to the datasheet for full pin configuration.
Typical Applications
MC9S12XET256MAA is suitable for 6 applications: Automotive Body Control Modules, Instrument Cluster Control, Industrial Automation Controllers, HVAC and Climate Control Systems, Motor Control Panels, Building Management and Networked Control Nodes.
Automotive Body Control Modules
Body control modules (BCM) coordinate lighting, door locks, window lifts, and wiper functions across a vehicle CAN network. The MC9S12XET256MAA fits this role with its 5 V tolerant I/O architecture, -40C to +125C operating range, and 59 GPIO - enough to drive multiple lamp and relay outputs directly. The 8-channel 12-bit ADC reads switch clusters and analog sensors such as ambient light, while the S12XE family's MSCAN connectivity links the node to the vehicle bus. Using the XGATE co-processor to service timer and CAN interrupts keeps the 50 MHz main core free for the application state machine, improving real-time determinism. The 256 KB flash accommodates full BCM firmware including diagnostics and calibration tables without external memory.
Recommended
Instrument Cluster Control
Instrument clusters require a controller that can drive stepper gauges or LCD segments, read analog fuel and temperature sensors, and communicate over CAN or LIN with the vehicle network. The MC9S12XET256MAA's 12-bit ADC provides the resolution needed for accurate fuel-level and temperature conversion, while the ample GPIO count (59 pins) drives indicators, backlighting, and warning lamps. The -40C to +125C rating covers cabin and near-dash thermal environments, and the 5 V supply simplifies interfacing with legacy automotive sensors that output 0-5 V signals. The 256 KB flash holds cluster firmware, warning logic, and localized message tables, while the XGATE offloads display-refresh timing from the main CPU for glitch-free gauge motion.
Recommended
Industrial Automation Controllers
Industrial control panels and automation nodes benefit from the MC9S12XET256MAA's combination of 5 V noise-robust I/O, 12-bit ADC for sensor feedback, and generous GPIO for driving contactors, indicators, and reading limit switches. The 256 KB flash supports ladder-logic interpreters or structured application firmware, and the 4 KB EEPROM retains configuration parameters and counters through power cycles - a practical advantage over pure-flash parameter storage in high-write industrial logging. The extended -40C to +125C temperature range supports panel mounting near drives and power electronics where ambient temperatures rise. The S12XE architecture's well-documented register model and long-standing CodeWarrior toolchain support make maintenance of long-lived industrial products straightforward.
Recommended
HVAC and Climate Control Systems
Commercial and automotive HVAC controllers must read multiple temperature sensors, drive blower and damper outputs, and support network communication. The MC9S12XET256MAA's 8-channel 12-bit ADC digitizes NTC thermistor and pressure-sensor inputs with adequate accuracy for closed-loop temperature control, while 59 GPIO handle damper actuators, valve drivers, and user-interface buttons. The 5 V I/O tolerance interfaces directly with industry-standard HVAC sensors without level shifting. Its -40C to +125C range accommodates both rooftop-unit environments and automotive under-dash installations. The 256 KB flash stores control algorithms, duty-cycle scheduling, and fault-logging code, and the EEPROM bank safely holds setpoint and runtime-hour data across power interruptions.
Recommended
Motor Control Panels
The MC9S12XET256MAA serves motor control panel applications requiring PWM generation, current and voltage feedback, and protective logic. The S12XE family's enhanced capture timer modules generate PWM outputs for inverter or DC drive stages, while the 12-bit ADC samples phase currents and bus voltage for closed-loop control and overcurrent protection. The 50 MHz HCS12X core executes FOC-lite or scalar control algorithms within the bandwidth needed for fans, pumps, and conveyors, and the XGATE can service fast fault interrupts independently. Operating from a 5 V rail with 125C junction capability, the MCU survives drive-enclosure thermal conditions. The 256 KB flash accommodates control firmware plus parameter menus and fieldbus protocol stacks.
Recommended
Building Management and Networked Control Nodes
Distributed building automation nodes - lighting controllers, access panels, energy meters - use the MC9S12XET256MAA as a cost-effective networked controller. Family-typical CAN/serial interfaces connect nodes to building buses, the 12-bit ADC measures current and temperature for energy metering functions, and the large GPIO allocation drives relays and reads keypads. The 4 KB EEPROM provides wear-tolerant storage for configuration, schedules, and cumulative counters, which is critical in metering products. The -40C to +125C range covers unconditioned plant rooms, and the 256 KB flash holds protocol stacks plus application logic. Long product lifecycles on the S12 platform simplify 10+ year service commitments common in building infrastructure.
Recommended
Recommended Products Summary
Engineering reference data for MC9S12XET256MAA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | S912XET256J2VAG | MC9S12XDT256MAA | MC9S12XDT512MAA | S912XET512J2VAGR | MC9S12XA256CAAR |
|---|---|---|---|---|---|---|
| Package | 80-QFP (14 x 14 mm) | 80-QFP (14 x 14 mm) - same | 80-QFP (14 x 14 mm) - same | 80-QFP (14 x 14 mm) - same | 80-QFP (14 x 14 mm) - same | 80-QFP (14 x 14 mm) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HCS12X 16-bit CISC | HCS12X 16-bit CISC | HCS12X 16-bit CISC | HCS12X 16-bit CISC | HCS12X 16-bit CISC | HCS12X 16-bit CISC |
| Max Clock Frequency | 50 MHz | 50 MHz | 50 MHz | 50 MHz | 50 MHz | 50 MHz |
| Flash Memory | 256 KB | 256 KB | 256 KB | 512 KB | 512 KB | 256 KB |
| Family Generation | S12XE | S12XE | S12XD | S12XD | S12XE | S12XA |
Key Differentiators
- Current-generation S12XE silicon (vs MC9S12XDT256MAA)
- Flash headroom in the same footprint (vs S912XET512J2VAGR)
- Trade-off: XE peripheral support vs XA legacy continuity (vs MC9S12XA256CAAR)
Design Notes
The 80-pin QFP (14 x 14 mm) uses 0.5 mm pitch leads. For reliable reflow assembly, specify a 0.45 mm-wide stencil aperture per lead with ~1:1 area ratio, and extend pads 0.3-0.4 mm beyond the lead toe per standard QFP land-pattern practice. Place a decoupling network of at least one 100 nF ceramic per supply pin pair plus one bulk 10 uF capacitor close to the package. Route the crystal traces short and guard them from high-dV/dt GPIO switching to keep the 50 MHz system oscillator stable.
When substituting the S912XET256J2VAG (current ordering PN) or an XD-generation part for the MC9S12XET256MAA, do not assume register-level identity: the S12XD and S12XA generations configure EEPROM partitioning and XGATE differently from S12XE. Re-run flash programming algorithms and verify EEPROM erase/write code against the specific family reference manual. Also confirm the exact temperature and package suffix of the replacement ordering code - suffix letters (MAA, MAL, CAG) encode package and grade, and MAL is LQFP112, which is NOT footprint-compatible.
Run the MCU from a clean 5 V rail with local LDO-quality regulation; automotive 12 V rails require a transient-suppressed supply stage (reverse-polarity protection plus TVS clamping) ahead of the regulator. Estimated: at moderate GPIO loading (say 30 outputs at 10 mA equivalent switching load), internal plus I/O dissipation typically stays under a few hundred milliwatts, so a QFP-80 on a standard 2-layer board with adequate ground pour keeps junction rise small - but verify with your actual I/O switching profile at -40C to +125C extremes.
Compliance Information
Compliance status not stated in the provided web data. Consult the NXP product page (nxp.com/part/MC9S12XET256MAA) for current RoHS/REACH declarations and environmental quality documentation.
