tetrabiodistributed/papra-pcba

Investigate replacing the e-fuse with a toshiba part

Closed this issue · 7 comments

mmroden commented

Efuses are hard to find, we need a replacement part. This ticket is an investigation for whether this part can replace the existing efuse.

https://www.digikey.co.uk/en/products/detail/toshiba-semiconductor-and-storage/TCKE800NL-RF/12324957

mechatroniks-git commented

Quick comparison of features:

image

##TLDR:

Toshiba

  • Toshiba part will be easier to solder and should have less components required
  • Toshiba requires external MOSFET for reverse polarity protection

TI

  • TI part is cheaper and more featured
  • TI has adjustable Overvoltage, Toshiba has a fixed value @ 15.1V
  • TI has slightly lower on-resistance (less heat) - but still good
  • TI has status outputs
  • TI has better nuisance tripping resilience

image

mechatroniks-git commented

TI circuit:

image

Toshiba Circuit:
image

darraghbr commented

Just a couple of quick agenda items for the meeting.

  • What is the stock like for the transient suppression diodes and the external FET
  • Do we currently take advantage of the reverse polarity protection on the current board rev (I seem to recall that we do) and do we think that it is necessary to keep that functionality (I think it is)
mechatroniks-git commented

Reverse polarity is a good thing, certainly worth the $.31 per board.

These are the recommended parts, all made by Toshiba. Cost at 100 board qty. Lots of stock at the moment.
TVS: Lots of stock, $0.20/board octopart
SBD: Lots of stock, $0.22/board octopart
FET: Lots of stock, $0.31/board octopart

mechatroniks-git commented

With Texas Instruments showing stock, request was made to order 250 parts for stock to avoid having to design in the Toshiba part.

Closing this issue for the time being.