MCIMX281AVM4B Freescale Semiconductor, MCIMX281AVM4B Datasheet - Page 2

• Manufacturer Part Number: MCIMX281AVM4B
• Description: IC MPU I.MX28 1.2 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX281AVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

PCB Stack-up
1
At minimum, the PCB should use a 4 or 6 layer stack-up. An 8 layer board may be required for extremely
dense PCBs that have multiple DRAM components. The 4 and 6 layer PCB stack-ups below keep a GND
plane adjacent to the power planes as well as the i.MX28 processor. This increases the capacitance and
reduces the gap between the GND and power planes. It will also ensure the signals on the top layer have
a solid GND reference plane and reduces the GND via impedance between the i.MX28 processor and GND
plane. This helps to reduce PCB and i.MX28 processor radiated emissions. The 6 layer PCB stack-up has
an additional solid ground plane on layer 5. This further improves the radiated emissions performance of
the PCB by ensuring all PCB layers have an adjacent GND reference plane.
2
2.1
Use at least one internal ground plane. It is recommend to use a solid ground plane without splits for analog
and digital GND planes. This allows for a continuous GND plane and helps to avoid radiated emissions,
ESD, and noise problems that result from signal traces crossing plane splits.
2.2
Split the power plane layer into separate VDDD (digital core), VDDA (analog supply), and VDDIO
(digital I/O supply) power planes. The example layout below shows a VDDD and VDDIO plane split.
2
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•
PCB Stack-up
Recommended 4 layer PCB stack-up:
— Layer 1 (Top) - i.MX28 location - signal + ground plane fill
— Layer 2 (Inner1) - complete ground plane, no signal traces
— Layer 3 (Inner2) - power planes + few signal traces if necessary
— Layer 4 (Bottom) - signal + ground plane fill
Recommended 6 Layer PCB stack-up
— Layer 1 (Top) - i.MX28 location - signal + ground plane fill
— Layer 2 (Inner1) - complete ground plane, no signal traces
— Layer 3 (Inner2) - power plane + few signal traces if necessary
— Layer 4 (Inner3) - signal
— Layer 5 (Inner4) - complete ground plane, no signal traces
— Layer 6 (bottom) - signal + ground plane fill
PCB Planes
Ground Plane
Power Planes
i.MX28 Layout and Design Guidelines, Rev. 0
Freescale Semiconductor