Schematic Checklist - Espressif Systems ESP32-C3 Series Hardware Design Manuallines

2 Schematic Checklist

2. Schematic Checklist
Thanks to high integration, ESP32-C3 family has simpler peripheral circuit design.The core circuit requires about
20 resistors, capacitors and inductors in total, as well as 1 crystal and 1 SPI flash. This document explains in
detail the schematics and PCB layout of ESP32-C3 family.
Figure 1 shows the core circuit of ESP32-C3 family.
5
The values of C1 and C2 vary with
D
the selection of the crystal.
The value of R1 varies with the actual
PCB board.
VDD33
C3
1uF
VDD33 GND
L1
C5 C6
C
10uF 0.1uF
GND GND
ANT1
1 RF_ANT L2
2
C8
PCB_ANT
TBD
GND GND
The values of C8, L2 and C9
vary with the actual PCB board.
B
A
Highlights in ESP32-C3 family circuit design may be broken down into nine major sections:
• Power supply
• Power-on sequence and system reset
5
• Flash
• Clock source
• RF
• UART
• ADC
• Strapping pins
• GPIO
Espressif Systems
4
TBD
C4
10nF
GND
GND
2.0nH
C7
0.1uF
GND
TBD LNA_IN 1
LNA_IN
2
VDD3P3
3
C9
VDD3P3
GPIO0 4
XTAL_32K_P
TBD 5
GPIO1
XTAL_32K_N XTAL_32K_N
GPIO2 GPIO2 6 6
GPIO2
CHIP_EN 7
CHIP_EN
GND
GPIO3 8
GPIO3
R8
10K
U2
VDD33
GPIO4
GPIO5
GPIO6
GPIO7
GPIO8
GPIO9
GPIO10
Figure 1: ESP32­C3 Family Schematic
VDD33
Y1
4
R1 0
VCC OUT
C1 1
NC GND
10nF
40MHz(±10ppm)
GND
4
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3
GND
GND GND
U1
C1 C2
TBD
GND
40MHz(±10ppm)
R2
24 R3
SPIQ
23 R4
SPID
22 R5
SPICLK
21
SPICS0
20
R6
SPIWP SPIWP
19 19 R7 R7
SPIHD
18
VDD_SPI
17
VDD3P3_CPU
C10
0.1uF
GND
ESP32-C3
C12
0.1uF
GND
3 TBD XTAL_P
L3
2
GND
3
5
2
499 U0TXD
U0RXD
GPIO19
GPIO18
0 SPIQ
0 SPID
0 SPICLK
SPICS0
1
0 SPIWP SPICS0
0 0 SPIHD SPIHD
SPICLK 6
VDD_SPI
SPIHD 7
C11
VDD33 U3
1uF
GND
VDD33
If using ESP32-C3FN4 or ESP32-C3FH4,
external flash could be removed.
2
ESP32-C3 Family Hardware Design Guidelines V0.5
VDD_SPI
5
SPID
/CS /CS DI DI
2 SPIQ
CLK DO
3 SPIWP
/HOLD /WP
FLASH-3V3
GND
1
1