Spark Logic

GD32F103 connection guide

GD32F103 LQFP48 wiring guide with power, signal assignments, and bench checks.

LQFP48

48 contacts Current package
LQFP64 64 contacts
LQFP100 100 contacts

GigaDevice · GD32F103Cx · 48 leads

128 KiB Flash · 20 KiB SRAM

Power and boot from Flash

Required

Use a regulated 3.3 V supply and a single ground plane. Feed VBAT from the same rail for this single-supply setup. Fit each bypass capacitor close to its corresponding contacts. Pull BOOT0 low with 10 kΩ.

4.7 µF bulk between +3.3 V digital and Digital return+3.3 V digital4.7 µF bulkDigital return
100 nF × 3, one at each VDD lead between +3.3 V digital and Digital return+3.3 V digital100 nF × 3, one at each VDD leadDigital return
1 µF in parallel with 10 nF at VDDA between +3.3 V analog and Analog return+3.3 V analog1 µF in parallel with 10 nF at VDDAAnalog return
100 nF between Backup supply and Digital returnBackup supply100 nFDigital return
10 kΩ between Boot strap and Digital returnBoot strap10 kΩDigital return

Bench checks

  • Verify continuity from every supply and ground lead to its intended rail before powering up.
  • Confirm that the digital and analog rails are near 3.3 V and that BOOT0 remains low through reset.

GD32F103xx datasheet Rev. 3.3, §3.3 and Fig. 4-1. The 10 kΩ strap is a bench choice.

Connection scenarios

Read a 3.3 V UART console

Use a 3.3 V logic-level UART adapter and set the same baud rate, parity and stop bits at both ends. Configure the default PA9/PA10 USART0 assignment in firmware.

Bench checks

  • Leave the adapter’s power output disconnected when the target has its own supply.
  • Transmit a known string from the target and verify both bit timing and the decoded text.

GD32F103xx datasheet Rev. 3.3, §2.6, USART0_TX and USART0_RX pin assignments.

LQFP48 wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

LQFP48
Top view. Pin 1 is beside the corner mark. Numbers advance counterclockwise. Scroll the map to reach all contacts.
Selected pin details

24 · VDD_1

Supply input · Power

Digital supply. Connect every VDD lead and place a local 100 nF bypass at each supply pair.

GD32F103xx datasheet Rev. 3.3, Table 2-8

Electrical limits · Pin in the reference

Models and documents

Interactive maps cover LQFP48, LQFP64 and LQFP100. See Figures 2-3 and 2-7 of the datasheet for LQFP144 and QFN36. Match the suffix on the chip. Board headers and regulator connections depend on the PCB.

GD32F103C4T6
16 KiB Flash · 6 KiB SRAM
GD32F103C6T6
32 KiB Flash · 10 KiB SRAM
GD32F103C8T6
64 KiB Flash · 20 KiB SRAM
GD32F103CBT6
128 KiB Flash · 20 KiB SRAM