2. Schematic Checklist and PCB Layout Design
• RF
• ADC
• External capacitors
• UART
2.1.1 Power Supply
For further details of using the power supply pins, please refer to Section 2.3 Power Scheme in ESP32 Datasheet.
2.1.1.1 Digital Power Supply
Pin19 and pin37 are the power supply pins for RTC and CPU, respectively. The digital power supply operates in
a voltage range of 1.8 V ~ 3.6 V. We recommend adding extra filter capacitors of 0.1 µF close to the digital power
supply pins.
VDD_SDIO works as the power supply for the related IO, and also for an external device.
• When VDD_SDIO operates at 1.8 V, it can be generated from ESP32’s internal LDO. The maximum current
this LDO can offer is 40 mA, and the output voltage range is 1.65 V ~ 2.0 V. When the VDD_SDIO outputs
1.8 V, the value of GPIO12 should be set to 1 when the chip boots and it is recommended that users add a
2 kΩ ground resistor and a 4.7 µF filter capacitor close to VDD_SDIO.
• When VDD_SDIO operates at 3.3 V, it is driven directly by VDD3P3_RTC through a 6 Ω resistor, therefore,
there will be some voltage drop from VDD3P3_RTC. When the VDD_SDIO outputs 3.3 V, the value of GPIO12
is 0 (default) when the chip boots and it is recommended that users add a 1 µF capacitor close to VDD_SDIO.
VDD_SDIO can also be driven by an external power supply.
When using VDD_SDIO as the power supply pin for the external 3.3 V flash/PSRAM, the supply voltage should be
2.7 V or above, so as to meet the requirements of flash/PSRAM’s working voltage.
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
The capacitance of C1 and C2 varies
with the selection of the crystal.
SENSOR_VP
SENSOR_VN
GPIO32
GPIO33
CHIP_PU
GPIO35
SCK/CLK
SCS/CMD
SENSOR_VP
SHD/SD2 SWP/SD3
SDI/SD1
SDO/SD0
SENSOR_VN
GPIO34
GPIO26
GPIO27
GPIO14
GPIO12
GPIO2
GPIO15
GPIO0
GPIO18
GPIO2
U0TXD
U0RXD
GPIO22
GPIO21
GPIO4
GPIO19
SHD/SD2
SWP/SD3
SCS/CMD
SCK/CLK
SDO/SD0
SDI/SD1
GPIO23
CHIP_PU
GPIO34
GPIO35
GPIO25
GPIO26
GPIO27
GPIO14
GPIO12
GPIO13
GPIO0
GPIO15
GPIO4
GPIO16
GPIO5
GPIO17
GPIO32
GPIO33
GPIO21
U0TXD
U0RXD
GPIO25
GPIO13
GPIO16
SDI/SD1
SDO/SD0
SCK/CLK
SCS/CMD
SWP/SD3
SHD/SD2
GPIO5
GPIO18
GPIO23
GPIO17
GPIO19
GPIO22
GND
VDD33
GND
VDD33
GND
GND
GND
VDD33
GND
GND
VDD_SDIO
GND
VDD_SDIO
GND
GND
GND
GNDGND
GND
VDD33
VDD33
GND
GNDGND
GND
GND
GND
GND GND
VDD33
GND
GND
Title
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ESP-WROOM-32-5X5
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Title
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ESP-WROOM-32-5X5
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1 1Tuesday, July 03, 2018
Title
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ESP-WROOM-32-5X5
A2
1 1Tuesday, July 03, 2018
L5
2.0nH
R1 20K(5%)
C13
10uF
U3 FLASH
/CS
1
DO
2
/WP
3
GND
4
DI
5
CLK
6
/HOLD
7
VCC
8
J30
CON1
1
J23
CON1
1
C5
10nF/6.3V(10%)
C14
TBD
J26
CON1
1
J31
CON1
1
C6
3.3nF/6.3V(10%)
D1
ESD3.3V88D-LCDN
C9
0.1uF
J4
CON1
1
R3 499R
C11
1uF
J22
CON1
1
J14
CON1
1
J35
CON1
1
C15
TBD
J36
CON1
1
J12
CON1
1
ANT1
PCB ANT
1
2
C16
270pF(NC)
J7
CON1
1
J25
CON1
1
J21
CON1
1
J6
CON1
1
J33
CON1
1
J17
CON1
1
J32
CON1
1
C17
270pF(NC)
J10
CON1
1
J1
CON1
1
J15
CON1
1
J3
CON1
1
J24
CON1
1
J37
CON1
1
J27
CON1
1
J2
CON1
1
U2 ESP32-D0WD
VDDA
1
LNA_IN
2
VDD3P3
3
VDD3P3
4
SENSOR_VP
5
SENSOR_CAPP
6
SENSOR_CAPN
7
SENSOR_VN
8
CHIP_PU
9
VDET_1
10
VDET_2
11
32K_XP
12
32K_XN
13
GPIO25
14
GPIO26
15
GPIO27
16
MTMS
17
MTDI
18
VDD3P3_RTC
19
MTCK
20
MTDO
21
GPIO2
22
GPIO0
23
GPIO4
24
VDD_SDIO
26
GPIO16
25
GPIO17
27
SD_DATA_2
28
SD_DATA_3
29
SD_CMD
30
SD_CLK
31
SD_DATA_0
32
GND
49
SD_DATA_1
33
GPIO5
34
GPIO18
35
GPIO19
38
CAP2
47
VDDA
43
XTAL_N
44
XTAL_P
45
GPIO23
36
U0TXD
41
GPIO22
39
GPIO21
42
VDD3P3_CPU
37
CAP1
48
VDDA
46
U0RXD
40
C20
1uF
L4 TBD
C1
TBD
C18
1uF
J20
CON1
1
J16
CON1
1
J5
CON1
1
C12
NC
U1
40MHz+/-10ppm
XIN
1
GND
2
XOUT
3
GND
4
C21
NC
J29
CON1
1
J8
CON1
1
J13
CON1
1
C2
TBD
J19
CON1
1
J9
CON1
1
C4
0.1uF
C10
0.1uF
C3
100pF
J34
CON1
1
C19
0.1uF
J11
CON1
1
J38
CON1
1
R2
0R
J28
CON1
1
J18
CON1
1
Figure 2: ESP32 Digital Power Supply Pins
Espressif Systems 3 ESP32 Hardware Design Guidelines V2.7
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