• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

TP4056 Li-Ion Charger Chip Exposed Pad Connection?

Visitor

Well-Known Member
I'm using a TP4056 chip from JLC to charge a Li-Ion battery in something I'm designing. It seems straightforward enough, and JLC includes it in their assembly program.

One small problem – the datasheet is in Chinese, and it's not clear where the exposed power pad should be connected. I suspect it should be grounded, but I'm not certain.

Has anybody here used this chip?

Thanks.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
I've not used it, but there are a lot of things online that do, including some bare PCBs to take it.

The ones I can see clearly all seem to have the underside thermal pad connected to input & battery negative, as you suspect.
Some also have VIAs in that area to improve thermal conductivity through to the board underside.
 

Visitor

Well-Known Member
I didn't think to look for bare circuit boards. Great idea.

My charge current is going to be pretty modest, so I probably don't need a lot of heatsinking.

Thanks for the info.
 

ronsimpson

Well-Known Member
Most Helpful Member
My Chinese is not good but I think the data sheet said Ground or Independent. So the heatsink pad may be floating. I found a PCB that looks like they connected to Vin.
1606611952603.png
1606612010083.png
 

Visitor

Well-Known Member
It does appear to be connected to V+. Maybe floating is the safest bet, with pads to short to V+ or ground just in case.
 

Visitor

Well-Known Member
I used Google Translate and got a reasonable translation of the data sheet.

It talks about the importance of the exposed pad and the need for heatsink area on the circuit board, but it makes no mention of any electrical connection to the pad.

Google Translate will translate an entire pdf document, but it leaves out the illustrations. I found it helpful to read the text in the translated pdf, which was a bit messy because it was in 2-column format and the translated columns overlapped. But understanding the captions on graphs are schematics was much easier using Goggle Lens on my phone. It translates whatever block of text it can see.
 

ljcox

Well-Known Member
I'm using a TP4056 chip from JLC to charge a Li-Ion battery in something I'm designing. It seems straightforward enough, and JLC includes it in their assembly program.

One small problem – the datasheet is in Chinese, and it's not clear where the exposed power pad should be connected. I suspect it should be grounded, but I'm not certain.

Has anybody here used this chip?

Thanks.
What does JLC stand for?
 

Visitor

Well-Known Member
JLCPCB. They make cheap circuit boards and offer incredibly cheap pcb assembly. It's almost a free service with a few limitations:

¤ They will only assemble components from their library (huge number of components offered)

¤ They only assemble SMT parts. Through-hole, you will have to solder yourself.

¤ They only assemble parts on one side of the board.

Heartily recommended.
 

Visitor

Well-Known Member
That's a "note to self". A full-size USB-B connector mounts there. There's an outline for it on the other side.

Being symmetric, it could mount on either side of the board, but if it's on the wrong side, power and ground aren't connected.
 

Latest threads

EE World Online Articles

Loading
Top