Are you designing a custom hat, hacking your hardware, or just dying to know how the Broadcom BCM2711 talks to the USB 3.0 controller? While the full, "no-secrets" BOM (Bill of Materials) is rarely released for Raspberry Pi flagship boards, the official Reduced Schematics
Technical Analysis of the Raspberry Pi 4 Model B Hardware Design
Unlike its predecessors, which stacked RAM directly on top of the SoC (Package-on-Package), the Pi 4 features a discrete LPDDR4 RAM chip placed adjacent to the SoC. The schematic highlights a high-speed, 32-bit memory bus capable of addressing 1GB, 2GB, 4GB, or 8GB RAM variants. 2. Power Delivery Network (PDN) and the MaxLinear PMIC
The Raspberry Pi 4 Model B represents a monumental shift in the single-board computer (SBC) landscape. For hardware engineers, embedded developers, and advanced makers, understanding the official schematics is crucial for troubleshooting, custom hardware design, and optimization. Raspberry Pi 4 Model B Full Schematic
The Wi-Fi subsystem communicates with the BCM2711 via a dedicated SDIO (Secure Digital Input Output) interface. The Bluetooth module utilizes a high-speed UART interface.
Used for analog-to-digital sections, Wi-Fi chip, and specific SoC I/O blocks. The USB Type-C "CC" Resistor Fix
: The Pi 4 lacks the polyfuse found on older models, meaning users must ensure their power supply does not exceed the recommended 5.25V. High-Speed I/O and Connectivity Are you designing a custom hat, hacking your
The schematic shows two independent HDMI blocks connected directly to the BCM2711's video core.
: Power is typically supplied via a USB-C connector. The official schematic shows the CC1 and CC2 lines used for power negotiation. Early revisions (v1.1) had a known design flaw in this circuit where they shared a single pull-down resistor, which was corrected in revision 1.2 .
The Raspberry Pi 4 requires a stable 5V, 3A power source. The power subsystem on the schematic handles conversion, sequencing, and protection. The Wi-Fi subsystem communicates with the BCM2711 via
The heart of the Raspberry Pi 4 is the . This chip manages the main processing, graphics, and many peripheral interfaces. Processor: Quad-core Cortex-A72 (ARM v8) 64-bit SoC.
Analyzing the reveals an incredibly dense, world-class piece of electronic engineering. From the implementation of PCIe lanes for high-speed USB storage to the precision design of the dual-output micro-HDMI structures and flexible PMIC voltage routing, the hardware is built for robust compute operations. By understanding these electrical layouts, you can securely build custom enclosures, debug intricate communication protocols, and design stable, high-performance embedded systems.
The BCM2711 maps multiple hardware peripherals across the header. While older Pis were limited in concurrent hardware serial lines, the Pi 4 features up to four additional UARTs, four extra SPI buses, and four extra I2C buses accessible through alternate (ALT) pin configurations.
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