USB 2.0 hub based on SL2.1A

shell_up.STEP

shell_down.STEP

PDF_USB 2.0 Hub Based on SL2.1A.zip

Altium_USB 2.0 Hub Based on SL2.1A.zip

PADS_USB 2.0 Hub Based on SL2.1A.zip

BOM_USB 2.0 Hub Based on SL2.1A.xlsx

93760

CH340X-USB TYPE-C to TTL

A serial port debugging tool based on CH340X, which can be used to automatically download firmware for ESP8266/ESP32.

Product Introduction:
The CH340X-USB-TYPE-C to TTL module uses the CH340X as its core, with an internal crystal oscillator and a maximum baud rate of 2Mbps. It is software-compatible with the CH341 driver, features backflow protection, and provides corresponding communication and power interfaces. The communication interface has indicator lights to show the working status, ensuring stable communication and a compact size. It is a serial port tool for automatically downloading programs to ESP8266/ESP32.
Product Features:

USB TYPE-C interface:
Full-speed USB device interface, compatible with USB V2.0.
Fully compatible with serial port applications under Windows operating systems on the computer side, requiring no modification.
Hardware full-duplex serial port with built-in transmit/receive buffers, supporting baud rates from 50bps to 2Mbps.
Built-in firmware, software compatible with CH341, allowing direct use of the CH341 VCP driver.

Driver
download address: https://www.wch.cn/downloads/CH341SER_EXE.html

Pin Function Table




:


CH340X Module Pins


ESP8266/ESP32 Pins




1


3V3


3V3




2


GND


GND




3


RXD


TXD




4


TXD


RXD




5


IO0


IO0




6


RST


EN




 
Product 3D Rendering Images
 
 
Actual Product Photos
 

PDF_CH340X-USB TYPE-C to TTL.zip

Altium_CH340X-USB TYPE-C to TTL.zip

PADS_CH340X-USB TYPE-C to TTL.zip

BOM_CH340X-USB TYPE-C to TTL.xlsx

93762

Dual-channel small-size fixed-output DC-DC step-down module based on EG1163S

This project uses the EG1163S control chip. All parameters were calculated independently. Testing under no-heat-dissipation conditions showed a stable single-channel output of 19V 7A. After three minutes of stable operation at 7A, the highest stable temperature was observed at the MOSFETs: 53 degrees Celsius for the upper MOSFET and 48 degrees Celsius for the lower MOSFET. The measured ripple under a 7A load was 83.5mV.

This project is the first version of the gimbal power supply, designed for continuous 6*2A load operation 24/7 on a DJI battery.
It boasts extremely high cost-effectiveness, extremely high power density, relatively comprehensive protection, and no need for additional cooling. However,
it has drawbacks such as relatively high voltage ripple (83mV at full load), still relatively high heat generation (not tested under 24/7 full load), and a fixed output of only 19V.
Advantages:
High cost-effectiveness: Using free prototyping from LCSC, the component price (excluding XT30) is only around 14 RMB.
High power density: The board size is only 4.7*4.7cm, providing 19V 7A*2 (still being optimized, replacing MOSFETs, reducing gate resistance, etc.).
Protection measures: Using 5*6 packaged PMOS for reverse connection protection, high-side current sensing, setting output current thresholds, and EN undervoltage lockout to protect the battery.
Disadvantages:
Ripple does not meet requirements (below 100mV at full load), heat generation reaches 85 degrees Celsius, unsuitable for long-term stable operation. Gate rise time is too long, resulting in weak chip driving capability.
Improvement directions:
1. Use MOSFETs with smaller QG. The CSD18540 is used in this case, with a QG of 42nc, which is insufficient for driving the EG1163.
2. Connect a DAC interface to the feedback terminal for easy voltage adjustment.
3. Implement voltage and current detection at the output terminal for convenient microcontroller closed-loop control. 4.
Optimize the layout with larger openings to enhance heat dissipation.
5. Install electrostatic discharge (ESD) and TVS devices to ensure operational stability.
Note: The part number (MMB) is not entirely accurate; for example, the inductor value is 15uH. If copying, please carefully verify the information.
 
Efficiency: Input 146W, Output 140W (including line loss), efficiency 96%.
 
Update 1: After replacing the CSD18540 with an NTMS4C06N, the single-channel continuous load capacity without heat dissipation reaches 19V 8.9A. The gate resistor is 6.8Ω.
Below are test images.
Update 2: Previously, the ripple measurement did not have the 20M bandwidth limit enabled. After enabling it, the ripple measured at a 7A load was 83.5mV, meeting the usage requirements.
Update 3: Upgraded to a four-layer board, obtaining a complete ground plane!!!
7.5A temperature measurement