Design and Specifications#
In this chapter, we delve into the intricate design and detailed specifications of PocketBeagle 2, offering a thorough understanding of its hardware architecture. We begin with a high-level overview, presenting block diagrams that illustrate the main components and their interconnections, including the System on Chip (SoC), power management, memory, connectivity interfaces, and peripheral components. These diagrams provide a visual representation of the I2C tree, power distribution, and boot configurations, essential for grasping the board’s functionality.
The chapter then focuses on the heart of PocketBeagle 2, the AM6232 SoC. We explore its internal architecture, highlighting the dual ARM Cortex-A53 cores, Cortex-M4F core, and various integrated peripherals. Detailed figures illustrate the SoC’s functional blocks, decoupling capacitors, DDR controller, and power management, emphasizing the importance of each component in ensuring efficient and reliable operation.
Connectivity and expansion options are also covered extensively. We discuss the USB connections, cape headers, and the MicroSD card slot, which enhance the board’s versatility and usability. Additionally, we provide insights into the debug ports, including the serial debug port and JTAG connections, which are crucial for development and troubleshooting.
The power management section details the integrated circuits responsible for stable and efficient power delivery, such as the TPS6521903 PMIC, TLV62595 step-down converter, LM73100 power path management IC, and BQ21040 battery charger. Each component’s role in maintaining power integrity and optimizing consumption is explained, supported by relevant figures.
Finally, we present the mechanical specifications of PocketBeagle 2, including its dimensions, weight, and PCB details. This comprehensive overview ensures that you have a complete understanding of PocketBeagle 2’s design, capabilities, and potential applications, making it an invaluable resource for developers and engineers.
Block Diagram and Overview#
The figure below provides a high-level overview of PocketBeagle 2 hardware architecture, illustrating the main components and their interconnections. This includes the System on Chip (SoC), power management, memory, connectivity interfaces, and other peripheral components.
System on Chip (SoC): At the core of PocketBeagle 2 is the AM6232 SoC, which integrates dual ARM Cortex-A53 cores, a Cortex-M4F core, and various peripherals. This SoC is optimized for power efficiency and performance, making it suitable for a wide range of embedded applications.
- Power Management: The diagram highlights several power management ICs:
TPS6521903 PMIC: Manages multiple power rails, including buck converters and LDOs, to supply necessary voltages.
TLV62595 Step-Down Converter: Provides a stable 3.3V power supply with high efficiency.
LM73100 Power Path Management IC: Seamlessly switches between multiple power sources (VIN_5V, USB_5V, VBAT) to ensure stable system voltage.
- Memory Components: PocketBeagle 2 includes:
512MB LPDDR4 RAM: Ensures efficient data transfer and memory access.
- Connectivity Interfaces: The board offers various connectivity options:
USB Ports: For data transfer and power supply.
Cape Headers: P1 and P2 headers for expansion and additional peripherals.
MicroSD Card Slot: For additional storage and boot options.
- Debug Ports: Essential for development and troubleshooting:
Serial Debug Port: Compatible with the Raspberry Pi Debug Probe for UART communication.
JTAG: For in-depth debugging and programming.
This comprehensive block diagram is essential for understanding the intricate design and functionality of PocketBeagle 2, providing a visual representation of how each component interacts within the system.
Fig. 184 PocketBeagle 2 Block Diagram#
The following figure illustrates the I2C tree of PocketBeagle 2, showing the connections between the I2C master and various I2C slave devices on the board. The I2C tree is crucial for understanding the communication pathways and how different components interact with each other.
Key I2C Ports and Connections:
I2C |
Connection |
|---|---|
WAUP_I2C0 |
Connected to the TPS6521903 PMIC for power management control and monitoring. |
I2C0 |
Connected to the MSPM0L1105 microcontroller, which emulates an 8-channel 12-bit ADC and a 4KB EEPROM. |
I2C1 |
Available on the P1 cape header for additional peripherals and expansion options. |
I2C2 |
Also available on the P1 cape header for additional peripherals and expansion options. |
I2C3 |
Available on the P2 cape header for user-defined peripherals and custom applications. |
MCU_I2C0 |
Not connected to anything internally, thus can be used if someone wants to modify PocketBeagle 2 design to add something like a QWIIC connector. |
These connections ensure efficient communication and control across PocketBeagle 2, enabling robust and flexible system design.
Fig. 185 I2C tree#
The following figure shows the power tree of PocketBeagle 2, detailing the power distribution from the main power sources to various components on the board. This diagram is crucial for understanding how power is managed and distributed across the board to ensure stable and efficient operation.
Key Components and Power Paths:
VIN_5V: This is the primary power input, typically supplied by an external power adapter. It is the main source of power for the board when available.
USB_5V: This input comes from a USB connection. It serves as an alternative power source when VIN_5V is not available, allowing the board to be powered via a USB connection.
VBAT: This is the battery voltage input, used when neither VIN_5V nor USB_5V is available. It ensures that the board remains powered in portable applications.
Power Management ICs:
TPS6521903 PMIC: Manages multiple power rails, including buck converters and LDOs, to supply necessary voltages to various components. It ensures stable and efficient power delivery.
TLV62595 Step-Down Converter: Provides a stable 3.3V power supply with high efficiency, powering critical components on the board.
LM73100 Power Path Management IC: Seamlessly switches between VIN_5V, USB_5V, and VBAT to ensure a stable system voltage (VSYS). It prioritizes the highest available power source and transitions smoothly between sources to prevent power interruptions.
BQ21040 Battery Charger: Manages the charging of a single-cell Li-Ion or Li-Polymer battery. It features high-accuracy voltage regulation, programmable charge current, and thermal protection, ensuring safe and efficient battery charging.
Power Distribution:
3.3V Rail: Powers various components, including the SoC, memory, and peripheral interfaces. The TLV62595 step-down converter ensures a stable 3.3V supply.
1.8V and 1.2V Rails: These lower voltage rails are generated by the TPS6521903 PMIC and are used to power specific components that require lower operating voltages.
VDDA 0.85V: This rail powers the analog components of the SoC, ensuring precise analog signal processing.
VDD Core: Powers the core logic of the SoC, ensuring stable operation of the processor and integrated peripherals.
The power tree diagram provides a comprehensive overview of how power is distributed and managed across PocketBeagle 2, highlighting the role of each power management component in maintaining system stability and efficiency.
Fig. 186 Power tree#
System on Chip (SoC)#
PocketBeagle 2 is powered by the AM6232 SoC, which is a high-performance, low-power processor designed for embedded applications. The AM6232 integrates dual ARM Cortex-A53 cores, a Cortex-M4F core, and various peripherals to support a wide range of functionalities. It is optimized for power efficiency and performance, making it suitable for applications requiring robust processing capabilities while maintaining low power consumption. The AM6232 SoC functional block diagram below provides a detailed view of the internal architecture of the System on Chip. It highlights the various functional blocks such as the CPU cores, memory controllers, peripheral interfaces, and other integrated components. This diagram is essential for understanding how the SoC manages data flow and interacts with other hardware components on PocketBeagle 2 board.
Fig. 187 SoC functional block diagram#
Decoupling capacitors are used to filter out noise and provide a stable power supply to the SoC. They help in maintaining the integrity of the power signals by smoothing out voltage fluctuations and transient spikes, ensuring reliable operation of the SoC and preventing potential malfunctions due to power instability.
Fig. 188 SoC decoupling capacitors#
The following figure shows the DDR controller of the SoC, which manages the communication between the processor and the DDR memory. It ensures efficient data transfer and memory access, playing a crucial role in the overall performance of the system.
Fig. 189 SoC DDR controller#
The following figure shows the power capacitors used for the SoC. These capacitors are crucial for maintaining stable power delivery to the SoC, filtering out noise, and ensuring reliable operation by smoothing out voltage fluctuations.
Fig. 190 SoC power capacitors#
The following figure shows the power distribution for the SoC, detailing how power is supplied to various components within the SoC to ensure stable and efficient operation.
Fig. 191 SoC power#
The following figure shows the VSS (Ground) connection for the SoC. This connection is crucial for providing a common reference point for all the electrical signals and ensuring the proper operation of the SoC by stabilizing the voltage levels.
Fig. 192 SoC VSS (Ground) connection#
Boot Modes#
The following figure shows the boot configuration of PocketBeagle 2 for eMMC and microSD card versions of the board. Only the microSD version of the board is available, but someone customizing the design might make use of the eMMC boot capability by using the eMMC boot configuration.
By default, PocketBeagle 2 will boot from microSD card. If not present, PocketBeagle 2 attemps to boot via USB device firmware upgrade (DFU) mode.
If the USER button is held at power-up, PocketBeagle 2 will still attempt to boot from microSD card, but, if not present, will attempt to boot via UART.
Fig. 193 Boot configuration#
The following figure illustrates the bootstrap pins connection, which are used to select the boot mode during the power-up sequence.
Fig. 194 Bootstrap pins connection#
SoC GPIOs#
Power Management#
PMIC#
The TPS6521903 is a power management integrated circuit (PMIC) designed to provide efficient power management for PocketBeagle. It integrates multiple power rails, including buck converters and LDOs, to supply the necessary voltages to various components on the board. The PMIC ensures stable and reliable power delivery, optimizing power consumption and extending battery life.
Fig. 205 PMIC#
3V3 power#
The TLV62595 is a high-efficiency, synchronous step-down converter that provides a stable 3.3V power supply to various components on PocketBeagle 2. It features a wide input voltage range, low quiescent current, and excellent transient response, making it suitable for powering sensitive electronics and ensuring reliable operation.
Fig. 206 3V3 power#
Power path#
The LM73100 is a power path management IC that can be used to seamlessly switch between multiple power sources to generate a stable system voltage (VSYS). In this design, we have three power sources: VIN_5V, USB_5V, and VBAT. Here’s how each of these sources is utilized:
VIN_5V: This is typically the main power input, which could come from an external power adapter. The LM73100 prioritizes this input when it is available, ensuring that the system is powered by this stable and higher current source.
USB_5V: This input comes from a USB connection. When VIN_5V is not available, the LM73100 switches to USB_5V to power the system. This allows the device to be powered or charged via a USB connection when an external adapter is not connected.
VBAT: This is the battery voltage input. When neither VIN_5V nor USB_5V is available, the LM73100 switches to VBAT to ensure that the system remains powered. This is crucial for portable devices that need to operate on battery power when no external power sources are connected.
The LM73100 manages these inputs and switches between them to provide a stable VSYS output. It ensures that the highest priority power source is used first, and seamlessly transitions to the next available source if the current one is disconnected or falls below a certain threshold.
This power path management ensures that the system remains powered without interruption, providing a reliable and efficient power solution for various applications.
Fig. 207 Power path#
Battery charging#
The BQ21040 is a highly integrated Li-Ion and Li-Polymer linear battery charger device targeted at space-limited portable applications. The device operates from either a USB port or AC adapter and supports high input voltage. It features a high-accuracy voltage regulation, programmable charge current, and thermal regulation. The BQ21040 is designed to charge single-cell Li-Ion and Li-Polymer batteries and includes a power path management feature to power the system while charging the battery.
Key Features: - Input voltage range: 4.5V to 28V - Programmable charge current up to 800mA - High-accuracy voltage regulation - Thermal regulation and protection - Power path management - Status indication for charge and fault conditions
Applications: - Wearable devices - Fitness accessories - Portable medical devices - Bluetooth headsets - Other space-limited portable applications
On PocketBeagle 2, the BQ21040 is used to manage the charging of a single-cell Li-Ion or Li-Polymer battery. The BQ21040’s status indication feature provides feedback on the charging status and any fault conditions, making it easier to monitor the charging process. This integration of the BQ21040 in PocketBeagle 2 design enhances the device’s portability and reliability, making it suitable for various applications that require battery power.
Fig. 208 Battery charging#
Decoupling capacitors#
Fig. 209 VDD 1.2V capacitors#
Fig. 210 VDD 1.8V capacitors#
Fig. 211 VDD 3.3V capacitors#
Fig. 212 VDDA 0.85V capacitors#
Fig. 213 VDD core capacitors#
General connectivity and expansion#
USB connections#
Fig. 214 USB connections#
Cape headers#
P1 cape header#
Fig. 215 P1 cape headers#
P2 cape header#
Fig. 216 P2 cape headers#
MicroSD card slot#
Fig. 217 MicroSD card slot#
Fig. 218 MicroSD card power#
Todo
Add MicroSD card slot information
Buttons & LEDs#
User & Power Button#
Fig. 219 Buttons#
Todo
Add button details
LED Indicators#
Todo
Add information about LED indicators
Fig. 220 LED indicators#
Memory, Media, and storage#
Described in the following sections are the memory devices found on the board.
eMMC (not populated)#
The design includes a footprint for including eMMC flash storage, but it is not populated. For people who want to modify the design, this should be a helpful feature in the layout.
Fig. 221 eMMC flash storage (not populated)#
512MB LPDDR4#
Fig. 222 512MB LPDDR4 RAM#
Fig. 223 DDR power#
MSPM0 ADC & EEPROM#
The MSPM0L1105 is a versatile microcontroller that we are utilizing to emulate an 8-channel 12-bit ADC and a 4KB EEPROM. This microcontroller is connected to PocketBeagle via the I2C interface, allowing for efficient communication and data transfer.
1. The 8-channel 12-bit ADC provides high-resolution analog-to-digital conversion, enabling precise measurement of analog signals from various sensors and inputs. This is particularly useful for applications requiring accurate data acquisition and monitoring. 2. The 4KB EEPROM emulation offers non-volatile storage for configuration data, calibration parameters, and other critical information. This ensures that important data is retained even when the system is powered off, enhancing the reliability and functionality of PocketBeagle 2.
By integrating the MSPM0L1105, we can leverage its capabilities to expand the analog input and storage options of PocketBeagle 2, making it suitable for a wider range of applications and use cases.
Fig. 224 MSPM0L1105 as 8ch 12bit ADC & 4KB EEPROM#
Debug Ports#
Serial debug port#
PocketBeagle 2 features a JST-SH 1.00mm connector for UART, which is compatible with the Raspberry Pi Debug Probe. This connector allows for easy and reliable serial communication for boot time debugging purposes.
Fig. 225 Serial debug port#
TagConnect (JTAG)#
Fig. 226 JTAG#
Fig. 227 TagConnect (JTAG)#
Mechanical specifications#
Dimensions & Weight#
Parameter |
Value |
|---|---|
Size |
56 x 35mm |
Max heigh |
13.6 |
PCB Size |
55 x 35mm |
PCB Layers |
10–layers |
PCB Thickness |
1.6mm |
RoHS compliant |
Yes |
Net Weight |
12.7g |
Gross Weight |
19g |
Board Dimensions#
Fig. 228 PocketBeagle 2 RevA Dimensions#