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Raspberry Pi 3 Model B+

Category: Raspberry Pi
Manufacturer: Raspberry Pi Foundation
SKU: SC0025
Status: Active
Release Year: 2018
Form Factor: Raspberry Pi Model B
Read Time: ~8 min read

Image Gallery

Raspberry Pi 3 Model B+ top view
Raspberry Pi 3 Model B+ bottom view
Raspberry Pi 3 Model B+ pinout
Raspberry Pi 3 Model B+ top view
Raspberry Pi 3 Model B+ bottom view
Raspberry Pi 3 Model B+ pinout

Overview

The Raspberry Pi 3 Model B+ is the final revision of the Raspberry Pi 3 series, released in March 2018. It improves on the Raspberry Pi 3 Model B with a faster 1.4 GHz processor, dual-band 802.11ac Wi-Fi, faster Ethernet, and a PoE HAT header. It remains one of the most widely used Raspberry Pi boards for education, home automation, media centers, and embedded projects.

The 3B+ is often considered the sweet spot of the Pi 3 generation — more powerful than earlier Pi 3 boards yet more affordable than the Pi 4 series. Its dual-band Wi-Fi was a first for the Raspberry Pi line, significantly improving wireless reliability in congested 2.4 GHz environments.

Key Features

  • Broadcom BCM2837B0 quad-core ARM Cortex-A53 processor at 1.4 GHz
  • 1 GB LPDDR2-900 SDRAM
  • Dual-band 802.11 b/g/n/ac Wi-Fi (2.4 GHz and 5 GHz) — first Raspberry Pi with 5 GHz Wi-Fi
  • Bluetooth 4.2 with BLE support
  • Gigabit Ethernet over USB 2.0 (real throughput ~300 Mbps)
  • 4× USB 2.0 ports
  • 40-pin GPIO header compatible with all standard Raspberry Pi HATs
  • Full-size HDMI output up to 1080p60
  • Combined 3.5mm audio and composite video jack
  • CSI camera connector and DSI display connector
  • MicroSD card slot for OS and storage
  • PoE HAT header (4-pin) — enables Power over Ethernet with an optional PoE HAT

Technical Specifications

Specification Detail
CPU Broadcom BCM2837B0, quad-core ARM Cortex-A53 at 1.4 GHz
RAM 1 GB LPDDR2-900 SDRAM
Wi-Fi 802.11 b/g/n/ac dual-band (2.4 GHz + 5 GHz)
Bluetooth Bluetooth 4.2, BLE
Ethernet Gigabit Ethernet via USB 2.0 (actual throughput ~300 Mbps)
USB 4× USB 2.0
GPIO 40-pin header
Video Output 1× full-size HDMI (up to 1080p60)
Audio Output 3.5mm audio+composite jack, HDMI audio
Camera Interface 1× CSI connector
Display Interface 1× DSI connector
Storage microSD card slot
Power Input 5V DC via micro-USB, minimum 2.5A recommended
PoE 4-pin PoE HAT header (requires PoE HAT add-on)
Dimensions 85 × 56 mm

Pinout

The Raspberry Pi 3 Model B+ uses the standard 40-pin GPIO header shared by all Raspberry Pi Model B boards from the Pi 1 B+ onward.

Power Pins

Pins 1 and 17 provide 3.3V output. Pins 2 and 4 provide 5V output. Pins 6, 9, 14, 20, 25, 30, 34, and 39 are ground. The 3.3V rail can supply up to 50 mA for external components; the 5V rail is limited only by the power supply.

GPIO Pins

General-purpose input/output pins can be configured as digital input or output. All GPIO pins operate at 3.3V logic. Do not connect 5V signals directly to GPIO pins without a level shifter.

Communication Interfaces

Interface Pins Notes
SPI0 GPIO 9, 10, 11, 8, 7 MISO, MOSI, SCLK, CE0, CE1
I2C1 GPIO 2, 3 SDA, SCL (3.3V, with 1.8kΩ pull-ups)
UART0 GPIO 14, 15 TX, RX — shared with Bluetooth on Pi 3
I2S GPIO 18, 19, 20, 21 PCM CLK, FS, DIN, DOUT
PWM GPIO 12, 13, 18, 19 Hardware PWM channels

Power

The Raspberry Pi 3 Model B+ is powered via the micro-USB port and requires a stable 5V supply. The Raspberry Pi Foundation recommends a minimum of 2.5A to avoid undervoltage warnings, especially under load with USB peripherals connected.

An official PoE HAT accessory connects to the 4-pin PoE header and draws power from an 802.3af-compliant network switch, eliminating the need for a separate power cable.

Power Method Detail
Micro-USB 5V / 2.5A recommended
PoE HAT 802.3af Power over Ethernet via optional PoE HAT
GPIO 5V Pins 5V direct input (bypasses polyfuse — use with care)

On-Board Components

Component Description
BCM2837B0 SoC Main processor with CPU, GPU, and memory bus
LPDDR2 RAM 1 GB memory stacked on SoC package
CYW43455 Dual-band Wi-Fi and Bluetooth 4.2 combo chip
LAN7515 USB 2.0 hub + Gigabit Ethernet controller
HDMI port Full-size HDMI video output
CSI connector 15-pin ribbon cable port for Pi Camera
DSI connector 15-pin ribbon cable port for Pi Display
3.5mm jack Combined audio and composite video output
microSD slot Push-push card slot for OS and user storage
PoE header 4-pin header for PoE HAT accessory

Wireless Connectivity

The Raspberry Pi 3 Model B+ was the first Raspberry Pi to feature dual-band Wi-Fi, using a Cypress CYW43455 chip with a custom RF shield. The 5 GHz band offers lower interference and improved throughput compared to the 2.4 GHz-only radios in earlier Pi models.

Wireless Feature Detail
Wi-Fi Standard 802.11 b/g/n/ac
Frequency Bands 2.4 GHz and 5 GHz (dual-band)
Bluetooth Version 4.2
Bluetooth Modes Classic and BLE (Bluetooth Low Energy)
RF Module Cypress CYW43455 under metal RF shield

Getting Started

What You Need

  • Raspberry Pi 3 Model B+
  • MicroSD card (8 GB minimum, 16 GB or larger recommended, Class 10 or UHS-1)
  • 5V/2.5A micro-USB power supply
  • HDMI cable and monitor or TV
  • USB keyboard and mouse

Step 1 — Flash the OS

Download and install the Raspberry Pi Imager on your computer. Insert the microSD card into your computer, open the Imager, select your board (Raspberry Pi 3), choose an OS (Raspberry Pi OS is recommended), select the SD card, and click Write.

Step 2 — First Boot

Insert the flashed microSD card into the slot on the underside of the Pi 3 Model B+. Connect the HDMI cable, USB keyboard, and USB mouse, then plug in the micro-USB power supply. The Pi will boot automatically — no power button is needed.

Step 3 — Initial Setup

On first boot, the Raspberry Pi OS setup wizard will guide you through selecting language, timezone, and Wi-Fi network, and setting a password. After setup completes, the desktop environment loads.

Step 4 — Update the System

Open a terminal and run the following commands to update all installed packages:

import subprocess print("Open Terminal and run:") print("sudo apt update && sudo apt full-upgrade -y")

Step 5 — GPIO Blink Example

Connect an LED with a 330Ω resistor between GPIO 18 (pin 12) and a ground pin. Then run this Python script:

import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BCM) GPIO.setup(18, GPIO.OUT) try: while True: GPIO.output(18, GPIO.HIGH) time.sleep(1) GPIO.output(18, GPIO.LOW) time.sleep(1) except KeyboardInterrupt: pass finally: GPIO.cleanup()

Programming

The Raspberry Pi 3 Model B+ supports multiple programming languages out of the box.

Python

Python is the primary and recommended language for Raspberry Pi projects. The RPi.GPIO library provides GPIO control, and gpiozero offers a higher-level interface suited to beginners.

C and C++

C and C++ offer maximum performance and direct hardware access. The wiringPi and pigpio libraries provide GPIO access from C. GCC is pre-installed on Raspberry Pi OS.

Scratch

Scratch 3 is available in Raspberry Pi OS and is designed for young learners. It supports GPIO control through extensions, making it suitable for classroom projects.

Other Languages

Node.js, Java, and Ruby are all installable via apt. The Pi 3B+ is powerful enough to run lightweight development servers and scripting environments.

Applications

  • Desktop computer replacement for everyday tasks and web browsing
  • Home automation hub (Home Assistant, openHAB)
  • Media center (Kodi, LibreELEC)
  • Retro gaming console (RetroPie)
  • Network-attached storage (NAS) server
  • VPN server or Pi-hole ad blocker
  • Learning Python, Linux, and electronics
  • Robotics and IoT prototyping

Where to Buy

Equivalent Boards

Board Key Difference
Raspberry Pi 4 Model B Faster Cortex-A72 CPU, USB 3.0, up to 8 GB RAM, more capable
Raspberry Pi 3 Model B Older revision — single-band 2.4 GHz Wi-Fi, 1.2 GHz CPU
Raspberry Pi Zero 2 W Same BCM2837B0 chip but smaller form factor, lower cost, fewer ports

Documentation

Notes

  • The Raspberry Pi 3 Model B+ is compatible with all standard 40-pin Raspberry Pi HATs, including motor driver HATs, display HATs, sensor HATs (such as the Sense HAT), and the official PoE HAT.
  • The PoE HAT requires the 4-pin PoE header present on this board and compatible PoE-capable network switches or injectors (802.3af).
  • The 5 GHz Wi-Fi band availability depends on local regulations. In some countries, certain 5 GHz channels may be restricted.
  • The BCM2837B0 SoC includes an integrated heatspreader, improving thermal performance over the BCM2837 used in the Pi 3 Model B.

Community

Revision History

Version Date Notes
v1.0 2026-06 Initial entry