Analog Power Supply - Espressif Systems ESP32-S2 Hardware Design Manuallines

2. Schematic Checklist

2.1.2 Analog Power Supply

Pin1, pin3, pin4, pin20, pin51, and pin54 are the analog power supply pins, working at 2.8 V
noted that the sudden increase in current draw, when ESP32-S2 is in transmission mode, may cause a power rail
collapse. Therefore, it is highly recommended to add another 10 µF capacitor to the power trace, which can work
in conjunction with the 0.1 µF capacitor. In addition, a CLC filter circuit needs to be added near the power pins
(pin3 and pin4) so as to suppress high-frequency harmonics. The inductor's rated current is preferably 500 mA or
above. Refer to Figure 3
Notice:
• The recommended voltage of the power supply for ESP32-S2 is 3.3 V, and its recommended output current is 500
mA or more.
• It is suggested that users add an ESD protection diode at the power entrance.
Espressif Systems
5
and place the appropriate decoupling capacitor near each analog power pin.
D
VDD33
C2
100pF
VDD33
GND
C
VDD33
L1
C6 C7 C8
0.1uF
10uF 1uF
GND GND GND
ANT2
RF_ANT
1 L2
2
C11
PCB ANT
TBD
GND GND
B
The values of C11, L2 and C12
vary with the actual PCB board.
A
Figure 3: ESP32­S2 Analog Power Supply Pins
5
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4
GND
The values of C1 and C4 vary with
the selection of the crystal.
C1
The value of R4 varies with the actual
TBD
PCB board.
C3
1uF
GND
C5
0.1uF
GND
GND
2.0nH
C9
TBD
GND
1
VDDA
LNA_IN
TBD 2
LNA_IN
3
VDD3P3
4
C12
VDD3P3
GPIO0 5
GPIO0
6
TBD GPIO1
GPIO1
7
GPIO2
GPIO2
GPIO3 8
GPIO3
GPIO4 9
GND
GPIO4
GPIO5 10
GPIO5
GPIO6 11
GPIO6
GPIO7 12
GPIO7
GPIO8 13
GPIO8
GPIO9 14
GPIO9
U1
VDD33
C15
0.1uF
GND
4
4 ESP32-S2 Hardware Design Guidelines V1.1
~ 3.6 V. It should be
3
GND
Y1 GND
C4
TBD
GND
R4
0 40MHz (±10ppm)
R3
C10
0.1uF
GND
42
GPIO38
41
GPIO37
40
GPIO36
39
GPIO35
38
GPIO34
37
GPIO33
36
SPID
35
SPIQ
34
R10
SPICLK
33
SPICS0
32
SPIWP
31
SPIHD
30
VDD_SPI
29 GPIO26
SPICS1
C13
ESP32-S2 0.1uF
GND
R11 10K
C16
0.1uF
GND
3
2
CHIP_PU
GPIO46
GPIO45
U0RXD
499 U0TXD
GPIO42
GPIO41
GPIO40
GPIO39
VDD33
R8
10K(NC)
GPIO38 U
GPIO37
GPIO36 SPICS0 1
GPIO35
GPIO34 SPICLK 6
GPIO33
7
SPID SPIHD
SPIQ
SPICLK
0
SPICS0
SPIWP
SPIHD
NC: No compon
SPICS1
VDD_SPI
C14
R9
1uF
10K(NC)
U
GND SPICS1 1
VDD33
SPICLK 6
SPIHD 7
2