CONFIDENTIAL
Contents
Contents
1 Overview 5
2 Schematic Checklist 6
2.1 Power Supply 7
2.1.1 Digital Power Supply 7
2.1.2 Analog Power Supply 8
2.2 Power-on Sequence and System Reset 9
2.2.1 Power-on Sequence 9
2.2.2 System Reset 9
2.2.3 Power-up and Reset Timing 9
2.3 Flash and SRAM 10
2.3.1 SiP Flash and SiP PSRAM 10
2.3.2 External Flash and External RAM 10
2.4 Clock Source 11
2.4.1 External Clock Source (compulsory) 11
2.4.2 RTC (optional) 12
2.5 RF 13
2.6 UART 13
2.7 ADC 13
2.8 Strapping Pins 13
2.9 USB 15
2.10 Touch Sensor 16
3 PCB Layout Design 17
3.1 General Principles of PCB Layout 17
3.2 Positioning a Module on a Base Board 18
3.3 Power Supply 20
3.4 Crystal Oscillator 21
3.5 RF 22
3.6 Flash and PSRAM 24
3.7 UART 24
3.8 USB 24
3.9 Touch Sensor 24
3.9.1 Electrode Pattern 25
3.9.2 PCB Layout 25
3.9.3 Waterproof and Proximity Sensing Design 26
3.10 Typical Layout Problems and Solutions 27
3.10.1 Q: The current ripple is not large, but the TX performance of RF is rather poor. 27
3.10.2 Q: The power ripple is small, but RF TX performance is poor. 27
3.10.3 Q: When ESP32-S3 sends data packages, the power value is much higher or lower than the
target power value, and the EVM is relatively poor. 28
3.10.4 Q: TX performance is not bad, but the RX sensitivity is low. 28
Espressif Systems 2
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ESP32-S3 Series Hardware Design Guidelines v1.0