Raspberry Pi - 4 Model B Full Schematic
The schematic enumerates all physical interfaces:
The LPDDR4 RAM is documented with:
When designing a HAT for the Pi 4, you cannot just copy the Pi 3 schematic. The Pi 4 has different voltage tolerances.
The Raspberry Pi Foundation publishes the official Raspberry Pi 4 Model B schematic PDF on its product documentation site; search “Raspberry Pi 4 Model B schematic” on Raspberry Pi’s documentation pages to download the official files.
The Raspberry Pi 4 is a triumph of integration. Looking at the full schematic moves you from being a user of the platform to a master of it. It demystifies the board and proves that the Pi isn't just a toy—it's a serious piece of embedded engineering.
So, download the PDF, zoom in on that PMIC block, and take a moment to appreciate the "blueprint" of the world's favorite single-board computer.
The full schematic of the Raspberry Pi 4 Model B is a masterclass in mixed-signal embedded design. It reveals the careful balance between performance, power efficiency, and cost. While not a complete blueprint for manufacturing (due to missing layout and exact BOM values), it remains an indispensable resource for anyone looking to interface deeply with the hardware. Whether you are troubleshooting a non-booting board, designing a professional expansion card, or simply learning how a modern SBC is architected, the schematic is your definitive guide.
Always remember: The schematic documents the board’s intended electrical behavior—real-world performance depends on physical layout, component quality, and operating environment.
Document version 1.0 – For use with Raspberry Pi 4 Model B (revisions 1.2, 1.4, 1.5). Raspberry Pi 4 Model B Full Schematic
Raspberry Pi 4 Model B Full Schematic is a critical resource for advanced users, hardware engineers, and developers looking to understand the intricate circuit design of the flagship single-board computer. Technical Breakdown & Layout Core Architecture : The schematic details the integration of the Broadcom BCM2711
SoC, highlighting the four Cortex-A72 CPU cores and the VideoCore VI GPU. Power Management : It maps out the transition to USB-C power
, specifying the required 5V/3A input and the internal voltage rails like the 3.3V supply for the GPIO bank. Peripheral Connectivity
: You’ll find clear diagrams for the dual micro-HDMI ports (supporting 4K), Gigabit Ethernet, and the mix of two USB 3.0 and two USB 2.0 ports. Expansion Headers : The document provides the exact pinout for the 40-pin GPIO header
, including labels for primary functions like SPI, I2C, and UART, as well as the PoE (Power over Ethernet) header. The Pi4J Project – Pin Numbering - Raspberry Pi 4B
Understanding the Raspberry Pi 4 Model B "Reduced" Schematic If you’ve ever looked for a "Full Schematic" of the Raspberry Pi 4 Model B
, you’ve likely hit a wall. Unlike early models, the Raspberry Pi Foundation now only releases Reduced Schematics. These official diagrams provide just enough detail for hardware designers and hobbyists to build add-ons without exposing proprietary design secrets. What’s Included in the Official Schematics?
The official documentation serves as a high-level technical reference for engineers. Key sections typically covered in these diagrams include: The schematic enumerates all physical interfaces: The LPDDR4
Broadcom BCM2711 SoC: The brain of the board, a 64-bit quad-core processor @ 1.8GHz.
40-pin GPIO Header: Detailed pinout for interfacing with sensors and HATs.
USB-C Power Input: Wiring for the 5V DC power supply (minimum 3A recommended).
Dual Micro HDMI Ports: Pin configurations for the two 4Kp60 supported displays.
PoE Header: Dedicated pins for using a Power over Ethernet HAT.
AV Jack: The 4-pole stereo audio and composite video port layout. Why You Won't Find a "Full" Version
The Raspberry Pi Foundation has explicitly stated in community forums that full schematics—including all component values, traces, and internal layers—are unlikely to be released. This is largely due to the proprietary nature of certain parts of the board design and the Broadcom SoC. Where to Find More Technical Details
For those looking to dive deeper than the basic schematics, you can reference these authoritative technical documents: Document version 1
Official Reduced Schematic (PDF): The most accurate starting point for hardware developers.
Raspberry Pi 4 Model B Datasheet: Includes electrical specifications, power requirements, and GPIO multiplexing modes.
Raspberry Pi 4 Product Brief: Provides physical specifications and mechanical dimensions in millimeters.
Pro Tip: If you are designing a custom PCB or carrier board, look into the Compute Module 4 (CM4) documentation. It is "loosely based" on the Pi 4 Model B
and often provides more granular interface data for industrial designers.
Are you planning to build a custom expansion board or just trying to troubleshoot a specific component on your Pi? Raspberry Pi 4 Model B specifications
For most makers, this is the most important page. The schematic maps every pin on the 40-pin header to the BCM2711 balls.
Why does this matter? Because the schematic shows the alternate functions. You can see exactly which pins can handle PWM, SPI, I2C, or UART. It also shows the pull-up/pull-down resistor configurations, which is vital for debugging why a sensor isn't working as expected.
You have a few options, though none are “official full schematics”: