LCSC EDA Instrumentation Training Camp Beginner Zone Replica [Hardwood Classroom] AFE03 Oscilloscope Signal Source Expansion Board

This LCSC EDA Instrumentation Training Camp will run from October 15th to November 20th, 2023. The I/O allocation for
this project is only applicable to the Hardwood Classroom H750 core board. For specific allocation details, please refer to the schematic
[https://oshwhub.com/damihuang/AFE03]. The training camp's open-source project provides a clearer and more in-depth explanation of the principles (this project only briefly introduces the ported circuitry; the official open-source code is worth careful reading).
The beginner's camp includes a replica of the PCB back panel (replacing the charging port with a Type-C port and adding a battery for portability).
![1700666135022.jpg] New schematic diagram for charging and discharging section: (TP4056 is a high-performance single-cell lithium-ion battery constant current/constant voltage linear charger. The TP4056 uses an ESOP8 package and requires fewer external components, making it ideal for portable products and suitable for powering USB and adapter power supplies. A charging current of 0.2C is recommended for lithium batteries.) ![image.png] The lithium battery voltage is approximately 3.7-4.2V, requiring a boost circuit to power the microcontroller. The MT3608 is selected, with an input of 2.2V - 16V and an output voltage up to 20V. When a 5V output is required, the schematic formula is Vout = 0.6 * (1 + R24/R25) = 4.9999999V (A shortcoming in this ported charging and discharging module: when powering the core board alone, it cannot charge the battery. The schematic should connect VBUS to the 5V-USB.)
![image.png] 5V Input Selection (Battery Power Not Used When Connected to TYPE-C) ① When USB is inserted, the diode is turned on, the gate of AO3401 is at a high level, the MOSFET is turned off, and BAT does not output. It is powered by USB and charges the battery at the same time. ② When USB is not inserted, the gate of the MOSFET is pulled low by the 10k pull-down resistor, and AO3401 is turned on. At this time, the 5V input selection is powered by battery BAT.