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
shows the core circuit of ESP32-C3 family.
5
4
3
2
1
D
D
C
C
The values of C1 and C2 vary with
the selection of the crystal.
The value of R1 varies with the actual
PCB board.
GPIO19
U0RXD
GPIO18
LNA_IN
GPIO0
GPIO1
SPICS0
SPID
SPIQ
SPICLK
SPIWP
SPIHD
GPIO2
RF_ANT
U0TXD
SPICS0
SPID
GND
VDD33
GND
GND
GND
GND
GND
VDD33
VDD_SPI
GND
GND
GND
GND
C1
TBD
C9
TBD
/CS
1
DI
5
V
C
C
8
R4
0
R7
0
R6
0
R
1
0
ANT1
PCB_ANT
1
2
R5
0
C3
1uF
R2
499
R3
0
L1
2.0nH
C2
TBD
C8
TBD
C6
0.1uF
L2
TBD
C5
10uF
C4
10nF
C7
0.1uF
LNA_IN
1
VDD3P3
2
VDD3P3
3
XTAL_32K_P
4
XTAL_32K_N
5
6
19
SPIWP
20
SPICS0
21
SPICLK
22
SPID
23
SPIQ
24
U
0
R
X
D
2
7
U
0
T
X
D
2
8
X
T
A
L
_
N
2
9
X
T
A
L
_
P
3
0
G
N
D
3
3
V
D
D
A
3
2
V
D
D
A
3
1
G
P
IO
1
9
2
6
G
P
IO
1
8
2
5
U1
40MHz(±10ppm)
X
IN
1
G
N
D
2
X
O
U
T
3
G
N
D
4
5
4
3
2
1
B
B
A
A
The values of C8, L2 and C9
vary with the actual PCB board.
If using ESP32-C3FN4 or ESP32-C3FH4,
external flash could be removed.
CHIP_EN
GPIO4
GPIO5
GPIO6
GPIO7
GPIO8
GPIO9
GPIO10
SPIHD
GPIO2
GPIO3
SPICLK
SPIHD
SPIWP
SPIQ
XTAL_P
GND
GND
GND
GND
GND
GND
VDD33
VDD_SPI
VDD33
GND
GND
VDD33
GND
VDD33
L3
TBD
U3
FLASH-3V3
/CS
DO
2
/WP
3
G
N
D
4
DI
CLK
6
/HOLD
7
V
C
C
R7
0
C12
0.1uF
C10
0.1uF
R1
0
C1
10nF
Y1
40MHz(±10ppm)
VCC
4
NC
1
GND
2
OUT
3
R8
10K
C11
1uF
U2
ESP32-C3
XTAL_32K_N
GPIO2
6
CHIP_EN
7
M
T
M
S
9
M
T
D
I
1
0
V
D
D
3
P
3
_
R
T
C
1
1
M
T
C
K
1
2
M
T
D
O
1
3
G
P
IO
8
1
4
G
P
IO
9
1
5
G
P
IO
1
0
1
6
VDD3P3_CPU
17
VDD_SPI
18
SPIHD
19
SPIWP
GPIO3
8
Figure 1: ESP32C3 Family Schematic
Highlights in ESP32-C3 family circuit design may be broken down into nine major sections:
• Power supply
• Power-on sequence and system reset
• Flash
• Clock source
• RF
• UART
• ADC
• Strapping pins
• GPIO
Espressif Systems
5
ESP32-C3 Family Hardware Design Guidelines V1.0