MCIMX257DJM4A557 - i.MX25 ARM926EJ-S MPU, 400MHz, 400-BGA | NXP Semiconductors
MPN: MCIMX257DJM4A557 ✓ ActiveMCIMX257DJM4A557 Overview
At the system level, a microprocessor IC (often called an MPU) is a highly integrated variant of a microcontroller that combines a CPU core, memory controllers, and application-specific peripherals on a single die. The i.MX25 sits in the hierarchy: ARM926EJ-S CPU -> i.MX applications processor family -> NXP Multimedia/Communications processors -> embedded MPU -> semiconductor IC. Distinguishing it from a microcontroller, an MPU typically relies on external SDRAM and flash, and the i.MX25 exposes EIM and SDRAM controllers for exactly this purpose.
Key features of the MCIMX257DJM4A557 include ARM926EJ-S at up to 400 MHz, 16 KB I-cache and 16 KB D-cache, MMU, integrated LCD controller with touchscreen interface, 10/100 Ethernet MAC, USB 2.0 OTG with PHY, CAN 2.0B, three UARTs, two CSPI, two I²C, I²S/AC97 audio, SD/MMC, and up to six PWM channels. Voltage rails are organized into core, I/O, and PLL supplies, with the on-chip voltage regulator supporting core domains.
Architecturally, the i.MX25 uses an ARM9TDMI-compatible core with a separate 16 KB instruction cache and 16 KB data cache, a write buffer, and a standard AMBA AHB/APB peripheral bus matrix. The integrated Image Processing Unit (IPU) supports LCD displays up to VGA (640x480), enabling HMI panels without an external graphics controller. Hardware accelerators for security (HAB/SCC) provide secure boot and cryptographic engine for protected content delivery.
Typical applications for the MCIMX257DJM4A557 include industrial human-machine interface panels, point-of-sale terminals, factory automation controllers, building automation gateways, medical patient-monitoring HMIs, and portable data terminals. Designers choose this MPU for its long-term industrial temperature support, ARM ecosystem maturity, and the i.MX25 reference design footprint provided by NXP.
When designing with the i.MX25, pay close attention to the power-up sequence: the I/O supply (typically 3.3 V) must be applied before or simultaneously with the core supply to avoid latch-up, and the reset signal must remain asserted until all clocks are stable. The BGA substrate also requires a 4-6 layer PCB with buried vias for the inner-ball breakouts and matched-impedance routing for the USB and Ethernet differential pairs.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives from the i.MX25 family, and practical layout guidance that goes beyond what is included in the manufacturer's standard product overview.
Drop-in alternatives for MCIMX257DJM4A557 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MCIMX257CJM4A
✅ Drop-InContact for price
View Datasheet →MCIMX257DJM4A
✅ Drop-InContact for price
View Datasheet →MCIMX255DJM4A
✅ Drop-In📋 Reference alternative (not in catalog)
MCIMX256DJM4A
✅ Drop-In📋 Reference alternative (not in catalog)
MCIMX258CVM4B
✅ Drop-In📋 Reference alternative (not in catalog)
MCIMX257DJM4A557 Maximum Ratings & Electrical Characteristics
| Processor Family | i.MX25 Multimedia Applications Processor |
| CPU Core | ARM926EJ-S |
| CPU Architecture | 32-bit RISC |
| Maximum CPU Frequency | 400 MHz |
| L1 Instruction Cache | 16 KB |
| L1 Data Cache | 16 KB |
| Memory Management Unit | Yes (MMU) |
| Ethernet | 10/100 MAC (FEC) |
| USB | USB 2.0 OTG with on-chip PHY |
| CAN | CAN 2.0B |
| LCD Controller | Up to VGA via integrated IPU |
| Touchscreen Interface | Yes (4-wire resistive via ADC) |
| External Memory Bus | EIM + SDRAM controller |
| Operating Temperature Range | -40C to +85C (industrial) |
| Package | 400-PBGA, 17x17 mm, 0.8 mm pitch |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MCIMX257DJM4A557 400-pbga, 17x17 mm, 0.8 mm pitch Pin Configuration Guide
Pin configuration for MCIMX257DJM4A557 (400-pbga, 17x17 mm, 0.8 mm pitch 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 MCIMX257DJM4A557.
Refer to the datasheet for full pin configuration.
Typical Applications
MCIMX257DJM4A557 is suitable for 6 applications: Industrial Human-Machine Interface (HMI) Panel, Point-of-Sale (POS) Terminal, Factory Automation Controller, Building Automation Gateway, Medical Patient-Monitoring HMI, Portable Data Terminal / Handheld Scanner.
Industrial Human-Machine Interface (HMI) Panel
The MCIMX257DJM4A557 is a strong fit for industrial HMI panels because its integrated LCD controller (up to VGA via the on-chip IPU) eliminates the need for an external graphics controller and reduces BOM cost. Operating at up to 400 MHz with 16 KB I/D caches, it renders meter graphics and operator menus at low CPU load. Placed as the main MPU between the touch-panel ADC and the display, it accepts the touch coordinates via ADC channels and writes pixels directly to the LCD bus. Unlike a microcontroller-based panel that needs an external SDRAM controller, the i.MX25's integrated EIM/SDRAM controller handles a single DDR-SDRAM chip for framebuffer memory while keeping pin-count manageable. The -40C to +85C temperature rating suits factory-floor environments without additional screening.
Recommended
Point-of-Sale (POS) Terminal
The MCIMX257DJM4A557 suits POS terminals because it integrates Ethernet, USB OTG, and CAN on-chip, allowing a bill/coin validator, NFC reader, and printer to attach with minimal external glue logic. The ARM926EJ-S core at 400 MHz handles encryption for payment flows alongside LCD drawing, while the MMU allows secure Linux runtime with memory protection between applications. Mounted on the main board with the on-chip FEC routed to an external PHY, designers get a complete networking stack without extra bridges. Compared with separate MPU + graphics chip designs, the i.MX25 integration cuts PCB area roughly 30-40% for space-constrained counter-top terminals where reliability and physical security matter as much as performance.
Recommended
Factory Automation Controller
The MCIMX257DJM4A557 delivers deterministic real-time response for factory automation thanks to its ARM926EJ-S core, hardware interrupt controller, and CAN 2.0B interface for industrial fieldbus connectivity. The integrated peripherals - PWM timers, UART, I²C, SPI - drive motor pre-drivers, sensors, and HMI displays from a single chip. Industrial-grade -40C to +85C operation handles cabinet-mounted installations. Unlike a microcontroller that requires external PHY and CAN chips, the i.MX25 cuts part count - a benefit when MTBF matters for 24/7 production lines. Programmable via IEC 61131-3 runtimes, it acts as a soft-PLC with deterministic Linux or RTOS scheduling on the MMU-enabled core.
Recommended
Building Automation Gateway
The MCIMX257DJM4A557 forms the heart of a building automation gateway, aggregating BACnet/Modbus/KNX traffic from sensors and forwarding to cloud services over Ethernet. The MMU-enabled ARM926EJ-S at 400 MHz runs embedded Linux with full IPv6 and TLS stacks, while the integrated FEC provides the wired backhaul and the USB OTG port supports Wi-Fi/Bluetooth dongles. A typical design fits in a DIN-rail enclosure with the MPU, an SDRAM chip, and a small SPI flash for firmware. Compared with discrete MPU + external MAC designs, the integrated peripherals cut power consumption to 1-2 W typical and simplify EMC certification.
Recommended
Medical Patient-Monitoring HMI
The MCIMX257DJM4A557 powers medical patient-monitoring HMIs where the integrated LCD controller drives a 640x480 color TFT, and the touchscreen ADC interfaces with a 4-wire resistive panel for glove-friendly input. Operating from -40C to +85C with an industrial specification, the device supports clinical room environments without additional screening. Designers use the i.MX25's MMU to isolate the patient-data GUI process from system services, helping meet IEC 62304 software lifecycle goals. The on-chip audio I²S/AC97 interface supports alarm tones and clinician voice prompts, eliminating a separate audio codec I²C bus. Power dissipation in typical GUI workloads is under 1.5 W, allowing fanless medical-cart designs.
Recommended
Portable Data Terminal / Handheld Scanner
The MCIMX257DJM4A557 fits portable data terminals and handheld scanners with its low-power ARM926EJ-S core (1-2 W active, sub-100 mW idle) and integrated USB OTG, making it easy to attach barcode imagers and charge cradles. The on-chip LCD controller drives a small QVGA panel suitable for handheld form factors, while the keypad scan matrix and PWM timers control backlight and beeper directly. A battery-powered design typically pairs the i.MX25 with a single-cell Li-ion charger and a buck-boost regulator for the 3.3 V main rail. Compared with microcontrollers that need an external SDRAM and LCD controller, the i.MX25 cuts PCB area substantially - critical for handheld ergonomics and IP54 enclosure integration.
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Recommended Products Summary
Engineering reference data for MCIMX257DJM4A557 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCIMX257CJM4A | MCIMX257DJM4A | MCIMX255DJM4A | MCIMX256DJM4A | MCIMX258CVM4B |
|---|---|---|---|---|---|---|
| Package | 400-PBGA (17x17, 0.8 mm pitch) | 400-PBGA (17x17, 0.8 mm pitch) - same | 400-PBGA (17x17, 0.8 mm pitch) - same | 400-PBGA (17x17, 0.8 mm pitch) - same | 400-PBGA (17x17, 0.8 mm pitch) - same | 400-PBGA (17x17, 0.8 mm pitch) - same |
| Brand | NXP Semiconductors (Freescale legacy) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| CPU Core | ARM926EJ-S 32-bit | ARM926EJ-S 32-bit | ARM926EJ-S 32-bit | ARM926EJ-S 32-bit | ARM926EJ-S 32-bit | ARM926EJ-S 32-bit |
| L1 Cache (I/D) | 16 KB / 16 KB | 16 KB / 16 KB | 16 KB / 16 KB | 16 KB / 16 KB | 16 KB / 16 KB | 16 KB / 16 KB |
| Ethernet MAC | 10/100 (FEC on-chip) | 10/100 (FEC on-chip) | 10/100 (FEC on-chip) | 10/100 (FEC on-chip) | 10/100 (FEC on-chip) | 10/100 (FEC on-chip) |
| USB | 1x USB 2.0 OTG (HS, PHY on-chip) | 1x USB 2.0 OTG (HS, PHY on-chip) | 1x USB 2.0 OTG (HS, PHY on-chip) | 1x USB 2.0 OTG (HS, PHY on-chip) | 1x USB 2.0 OTG (HS, PHY on-chip) | 1x USB 2.0 OTG (HS, PHY on-chip) |
| LCD Controller | Up to VGA via IPU | Up to VGA via IPU | Up to VGA via IPU | Up to VGA via IPU | Up to VGA via IPU | Up to VGA via IPU |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C / +105C (automotive) |
Key Differentiators
- Single die integration of LCD, Ethernet, USB OTG, and CAN (vs Discrete MPU + external controller design)
- Industrial -40C to +85C temperature range on every i.MX25 variant (vs i.MX27 and i.MX28 commercial-only variants)
- Mature ARM926EJ-S ecosystem with long-term Linux BSP support (vs Newer Cortex-A5/A7 migration paths)
- 400-ball PBGA shared across i.MX25 family (vs i.MX27/i.MX28 different BGA pinouts)
- On-chip security engine (HAB/SCC) (vs i.MX25 vs other ARM7-based MPUs)
Design Notes
The 400-PBGA at 0.8 mm pitch requires a minimum 4-layer PCB with laser-drilled or 0.2 mm mechanically drilled microvias for the inner-row ball breakouts. Use via-in-pad tented with solder mask to escape inner balls; via-in-pad eliminates the dog-bone trace that would otherwise violate the 0.4 mm minimum trace/space at the BGA fan-out. Plan a 1.6 mm panel thickness to balance via aspect ratio and controlled-impedance target of 50 ohm +/- 10% for the USB differential pair (D+/D-) and 100 ohm +/- 10% for Ethernet (TDP/TDN). For the RMII PHY interface, keep trace lengths matched within 50 mil. Reference NXP application note 'Hardware Design Guidelines for i.MX25' for full stackup examples.
The i.MX25 requires a sequenced power-up: NVCC (I/O supply, typically 3.3 V) must rise first or simultaneously with the core supply VDD (typically 1.45 V internal regulator output or external), and RESET_B must remain asserted until all clock sources (32 kHz and 24 MHz reference) are stable for at least 8 cycles. Use a supervisor like TPS3823 or STM7040 to hold reset during power-up, and place 100 nF X7R decoupling caps within 2 mm of every VDD pin on the package perimeter (approximately 16 caps for this 400-ball BGA). Add a 47 uF bulk cap on VDD_AUDIO for low-noise audio playback.
Estimated: with 1.45 V core and 400 MHz operation, typical core power dissipation is 0.7-1.0 W active and 50-100 mW idle, well within the 400-BGA theta_JA of approximately 25-30 C/W on a 4-layer JEDEC test board. The industrial -40C to +85C operating range is achievable without a heatsink if the board has continuous top and bottom copper ground pours under the BGA shadow area (at least 1 square inch of each). For systems sealed in IP54 enclosures with limited convection, plan thermal verification including Tj max of 105C.
Series-stubs and unmatched impedance cause USB OTG enumeration failures above 480 Mbps and Ethernet packet errors at 100 Mbps. For the D+/D- differential pair, keep total length under 50 mm with 90 ohm differential impedance (per USB 2.0 spec, calculated as Z0=50 ohm single-ended). For the RMII/MII signals to the external PHY, match trace lengths to within 100 mil and route them on the same layer to avoid via-induced skew. Place an external ESD array (e.g., IP4220CZ6) near the USB connector - the on-chip PHY ESD cell has limited HBM rating.
Do not assume all i.MX25 variants are bit-compatible in software - the i.MX257 (industrial 400 MHz) differs from the i.MX255 (lower speed) in PLL settings and DDR timing calibration registers; NXP provides per-variant board support packages, so source BSP for the exact MCIMX257DJM4A557 marking. Also watch for layout mistakes with the DDR clock - the SDRAM clock must be routed with 50 ohm characteristic impedance and isolated from noisy digital routes like the LCD data bus. Finally, do not populate the boot-mode pull-ups until you have read the System Boot chapter of the reference manual; wrong boot modes can lock the device during production.
Compliance Information
RoHS compliance per NXP product page and distributor listings. Not AEC-Q100 qualified; choose automotive variant MCIMX258CVM4B if required. Halogen-free status not stated explicitly in the verified web data and is set to [DATA_NEEDED].
