Is ESD/TSV needed if I use CH340N? - Page 1
Forum section: electronics / beginners

author: dusan
author_rank: Regular Contributor
timestamp: October 12, 2024, 12:48:56 pm
content: I use USB-C data pins DP,DN directly into CH340N. In other people's schematic I've seen using ESD/TSV device for example SOT-23-6 USBLC6-2SC6 (https://www.lcsc.com/datasheet/lcsc_datasheet_2108132230_TECH-PUBLIC-USBLC6-2SC6_C2827654.pdf), are these needed or will CH340N survive without it?CH340N is SOP-8 USB to UART convertor:https://cdn.sparkfun.com/assets/5/0/a/8/5/CH340DS1.PDF

author: PGPG
author_rank: Frequent Contributor
timestamp: October 12, 2024, 02:20:07 pm
content: Neither DigiKey nor Mouser knows CH340N.

author: ataradov
author_rank: Super Contributor
timestamp: October 12, 2024, 03:04:36 pm
content: It is not strictly necessary. Usually IC datasheets specify ESD characteristics of the device and if those characteristics meet your requirements, then you don't need additional protection.In this case datasheet does not specify anything like that, so you kind of have to guess. If you are doing mass produced things, I would add ESD protection. For small volume cheap stuff, I would not bother.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 13, 2024, 03:22:34 am
content: No mention of ESD rating in datasheet. If you're putting it on a connector, don't expect it to be very robust.In the middle of a circuit, joined to an MCU or whatever, no problem. Well, maybe you might still have concerns like assembly/service handling the boards without ESD precautions and thus ESD protection everywhere might be a thing? But that's kind of silly and easily solved with procedure.Tim

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 13, 2024, 03:57:31 am
content: The CH340 manufacturer (WCH, aka NanjingQinhengMicroelectronics; in my opinion a reputable Chinese manufacturer) page ishere, and the English datasheethere.USBLC6-2 is a series of two-channel ESD diode packages made by STmicroelectronics (seeST USBLC6-2) and others, probably the most common one used for USB devices. Most USB 2.0 device D+ and D- lines are rather robust, not that sensitive to EMI, and not easily charged to high voltages due to the physical structure of the connectors –– humans most often touch the shield, which means there might be an ESD spike to theground, not to the signal lines ––, so ESD diodes for USB 2.0 devices are not that common.I'm only a hobbyist, but I've looked at a lot of different native-USB and USB-to-Serial developer board and project schematics with USB 2.0 connectors, and they rarely have ESD protection on the USB device lines. So, they definitely are notrequired.I've wondered about the same thing, the need/use of ESD diodes for my own USB designs, especially sinceST USBLC6-2SC6Y(and similar at LCSC and elsewhere) are SOT23-6 with 0.95mm pitch (so hand-solderable) and quite cheap.My suggestion is if the device itself is cheap and replaceable, don't bother. If it is on a relatively expensive board (say, >15€ BOM cost for example), then adding the ESD is a minor cost addition for peace of mind.

author: R_YiDe
author_rank: Newbie
timestamp: October 14, 2024, 09:01:14 am
content: In fact, you need to decide whether to add ESD devices based on your actual design requirements. For the CH340N, ESD devices are not necessary.