Uart - Espressif Systems ESP32-H2 Series Hardware Design Manuallines

2 Schematic Checklist
VDD33
Figure 8 shows the general process of RF tuning. Please be noted the matching parameters are subject to the
RF tuning of PCB board, which depends greatly on the antenna and PCB layout. For ESP32-H2 series of chips,
it is recommended to set the S11 parameter in the figure below to 35+j5 Ω and the center frequency is 2442
MHz.
If the RF function is not required, the RF pin can be left floating.
If the application or production environment is susceptible to electrostatic discharge, it is recommended to
reserve an ESD protection diode near the antenna side.
5
Notice:
The matching parameters vary with board, so the ones used in our modules could not be applied directly.

2.6 UART

It is recommended to connect a 499 Ω series resistor to the U0TXD line in order to suppress the 80 MHz
harmonics.
Usually UART0 is used as the serial port for download and log printing, and UART0 pins (U0TXD and U0RXD) are
fixed. For instructions on download over UART0, please refer to Section 4.3.
Espressif Systems
C3
0.1uF
GND
ANT1
RF_ANT
1 L2
2
C11
PCB_ANT
TBD
GND GND
The values of C11, L2 and C12
vary with the actual PCB board.
L1
Figure 7: Schematic for RF Matching
C6 C7 C8
10uF 1uF 0.1uF
GND GND GND
Figure 8: RF Tuning Diagram
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C2
10nF
GND
LNA_IN
TBD
C12
GND
TBD
GND
0 1
2
C9 GPIO0 3
GPIO1 4
0.1uF GPIO2 5
GPIO3 6
GPIO4 7
GPIO5 8
GND
U1
VDD33
C17
0.1uF
GND
4
12
ESP32-H2 Series Hardware Design Guidelines v0.5
VDD3P3
VDD3P3
GPIO0
GPIO1
MTMS
MTDO
MTCK
MTDI
3
C
0
GND
GND
C
0
24
GPIO25
23
U0TXD
22
U0RXD
21
GPIO22
20
VDDPST2
19
VDDA_PMU
18 VBA
VBAT
17
CHIP_EN
C
0
GND
ESP32-H2