TP4056 - thermal pad

[papa_lazerous]

HI all,

I have been working on a project that I am using a TP4056 to charge a single 18650 cell, and it all works except the TP4056 gets too hot and fails after some time, the reason is I didn't include a thermal pad in Kicad to take the heat away from the die my fault as I designed the board before I had the chip in front of me and used the wrong footprint.

Now I am redesigning my board layout and will put a pad below the chip and some vias to get some of the heat away from the chip.  I cannot find any information on what I should connect to the pad to electrically.  I used a multimeter on continuity and the pad on the bottom of the chip is not connected to any of the pins on the chip.  That said I was going to connect it to the GND plane as that is the largest copper fill I have on the board.

I would be very appreciative of any advice on this, the link to the datasheet is below.  However it leaves allot of information out imho

https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/TP4056.pdf

[mikerj]

The datasheet states "Available Radiator in 8-Lead SOP Package,the Radiator need connect GND or impending".  "Impending" appears to be a bad translation, and might have meant "isolated" but it seems pretty clear that the pad can be safely connected to ground.

[papa_lazerous]

Thanks I will connect it to GND, a second set of eyes definitely helped as I looked over the datasheet multiple times and glossed right over that bit