2025-08-02 12:33 PM
We are designing a benchtop device with an LCD, battery, and wireless capabilities and have chosen the STM32H7A3ZIT6 MCU and ST67W611M WiFi/BT SoC. It's intended to use TouchGFX for the graphics. The board is complete and ready to order but I'd like a review of the hardware and schematic beforehand if possible as re-ordering and re-assembly with a mistake would take a while.
MCU schematic:
Power Section of MCU
Signals of MCU
The schematic symbol was manually created with the nucleo hardware files as reference.
MCU PCB:
PCB routing for MCUThe yellow plane is a 3v3 digital power pour. USB is the differential signal coming from the top left of the MCU. Most of the signals are going to the LCD connector to the right. I have placed capacitors on pins as follows:
Pin | Label | Capacitor |
6 | VBAT | None, connected to 3v3d |
30 | VDD_5 | 4.7uF |
32 & 33 | VDDA & VREFP | Tied together. 100nF and 1uF |
39, 52, 62, 72, 84, 108, 144 | VDD_7, VDD_9, VDD_11, VDD_16, VDD_2, VDD_13 | Separate. 100nF |
71, 106 | VCAP1 & VCAP2 | Tied together. 2.2uF near each pin. |
95 | VDD33_USB_1 | 100nF and 1uF |
131 | VDD_26 | 100nF in parallel with 100nF |
It is unclear to me exactly which of these are necessary. For example why pin 131 needs parallel 100nF capacitors as in the nucleo hardware.
Wireless schematic:
Wireless SoC Schematic
Wireless PCB:
Wireless SoC PCB routingST67W611M is placed on the top edge of the board such that the antenna is unobstructed. A ground pour is on layer 2 (not shown in images) underneath the entire board.
Thanks for any help
2025-08-07 2:09 AM
Hello @AuFries and welcome to the community;
I recommend you referring to Getting started with STM32H7A3/7B3 line and STM32H7B0 Value line microcontroller hardware development to check your PCB. This application note is intended for system designers developing applications based on STM32H7A3/7B3 line and STM32H7B0 Value line microcontrollers, and provides an implementation overview of the following hardware features:
• Power supply
• Package selection
• Clock management
• Reset control
• Boot mode settings
• Debug management
Also, the Evaluation board (STM32H7B3I-EVAL) and Discovery kit (STM32H7B3I-DK) are proven designs and must be used as foundations for specific application development.
I hope this help you.
Thank you.
Kaouthar
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