Schematic Checklist And Pcb Layout Design; Schematic Checklist; Esp32 Schematics (Esp32-D0Wd Used As An Example For All Illustrations In This Section) - Espressif Systems ESP32 Series Hardware Design Manuallines

2. Schematic Checklist and PCB Layout Design

2. Schematic Checklist and PCB Layout Design
ESP32's integrated circuitry requires only 20 resistors, capacitors and inductors, one crystal and one SPI flash
5
memory chip. ESP32 integrates the complete transmit/receive RF functionality including the antenna switches, RF
balun, power amplifier, low noise receive amplifier, filters, power management module, and advanced calibration
circuitries.
ESP32's high integration allows for simple peripheral circuit design. This document details ESP32 schematics and
PCB layout design.
While the high level of integration makes the PCB design and layout process simple, the performance of the system
strongly depends on system design aspects. To achieve the best overall system performance, please follow the
guidelines specified in this document for circuit design and PCB layout. All the common rules associated with
good PCB design still apply and this document is not an exhaustive list of good design practices.

2.1 Schematic Checklist

ESP32 schematics is as shown in Figure 1.
VDD33
VDD33
VDD33
C13 C12 C11
10uF NC 1uF
GND GND GND GND
ANT1
1 L4 TBD
2
C15 C14
PCB ANT
TBD TBD
GND GND GND
Figure 1: ESP32 Schematics (ESP32-D0WD used as an example for all illustrations in this section)
Any basic ESP32 circuit design may be broken down into eight major sections:
• Power supply
• Power-on sequence and system reset
• Flash
• Crystal oscillator
Espressif Systems
The capacitance of C1 and C2 varies
with the selection of the crystal.
C3 C20
GND
100pF 1uF
R1 20K(5%)
C5 C6
GND GND
10nF/6.3V(10%)
3.3nF/6.3V(10%)
C9
GND
0.1uF
GND
L5
2.0nH
C10 C21
0.1uF NC
GND
1
VDDA
2
LNA_IN
3
VDD3P3
4
C16
VDD3P3
SENSOR_VP
5
SENSOR_VP
270pF(NC) 6
SENSOR_CAPP
7
SENSOR_CAPN
270pF(NC) SENSOR_VN 8
SENSOR_VN
CHIP_PU 9
CHIP_PU
C17
GPIO34 10
VDET_1
GPIO35 11
VDET_2
12
GPIO32
32K_XP
GPIO33 13
32K_XN
GPIO25 14
GPIO25
U2
4
GND
GND
GND
U1
C1 C2
TBD
TBD
R2
GND
0R 40MHz+/-10ppm
R3 499R
GND
C4
0.1uF
38
GPIO19
37
VDD3P3_CPU
36
GPIO23
35
GPIO18
34
GPIO5
33
SD_DATA_1
32
SD_DATA_0
31
SD_CLK
30
SD_CMD
29
SD_DATA_3
28
SD_DATA_2
27
GPIO17
26
VDD_SDIO
25
GPIO16
ESP32-D0WD
GND
GND
2 ESP32 Hardware Design Guidelines V2.7
GPIO21
U0TXD
U0RXD
GPIO22
VDD33
VDD_SDIO
GPIO19
GPIO23
GPIO18
GPIO5
SDI/SD1 SCS/CMD 1
/CS DI
SDO/SD0
SCK/CLK SCK/CLK 6
CLK DO
SCS/CMD
SWP/SD3 SHD/SD2 7
/HOLD /WP
SHD/SD2
GPIO17 U3 FLASH
GPIO16
GND
C18
VDD_SDIO
1uF
VDD33
C19
0.1uF
3
J1
1
D
CON1
E
J4
1
CON1
J7
1 CHIP
CON1
J10
1 SENSO
CON1
J13
SENSO
1
CON1
J16
1 GP
CON1
J19
1 GP
CON1
J22
1 GP
CON1
J25
5 SDI/SD1 1 GP
2 SDO/SD0
CON1
3 SWP/SD3
J28
1
GP
CON1
J31
1 GP
CON1
J33
1 GP
CON1
J35
1 GP
CON1
J37
1 GP
CON1