Does 'Drop in replacement' strike fear into your Soul? It should...

I have been using IrDA (Infrared Optical transceivers) for several years for setting parameters and doing software updates in my designs. Takes far less space and power that WiFi or Bluetooth.

There was once many people making IrDA transceivers, back when they were used in Cell Phones before the era of Bluetooth, now there are only a couple of manufactures left. Once I had three sources for a footprint compatible part with the HP3003 that I originally started with. Over the years the only remaining footprint compatible part was the Vishay TFDU4300.

Sadly the day came when even the 4300 was discontinued, however I was assured that I was not going to have to do a new board spin, "you can drop our new TFDU4301 right in". While true that it was footprint compatible, it was not software compatible. The 4300 would not receive its own output and would drive its Rx line high during transmit. The 4301 echos the transmitted data, meaning all of the bootloaders had to be updated to turn off the receiver when transmitting. Annoying, but at least that was documented.

What was not documented is shown in the scope captures below. The first one shows the discontinued 4300 and the second shows the new 'drop in compatible replacement'. Does it look compatible to you?

Sadly this problem was discovered while I was far away trying to get my wife help with Intracranial Hypotension, more commonly known as a Cerebrospinal Fluid (CSF) Leaks, to stop her excruciating headache resulted from cerebrospinal fluid leakage. I made the mistake of putting my job first and we came home to Pittsburgh, when we should have stayed at Duke in North Carolina. This is one of the small events that accumulated to result in my wife's suicide.

Now does 'drop in replacement' strike fear into your Soul too?

Won 3rd place Dare-to-Dream Medtech Design Challenge

I won third place in Medical Device + Diagnostic Industry magazine's Dare-to-Dream Medtech Design Challenge.

MD+DI is a magazine written exclusively for original equipment manufacturers of medical devices and in vitro diagnostic products.

A month ago, the editors of MD+DI created a medtech design contest, where we challenged you to design your dream device under the assumption that real-world challenges were non-existent.

3 Dream Devices Take Top Honors in Medtech Design Contest
In August, the editors of MD+DI asked you, the medtech community, to put on your creative hats and dream up a device that would tackle health-care problems both big and small.

You responded, submitting an array of innovative medical device concepts that addressed a broad spectrum of issues. The editors of MD+DI reviewed and debated the merits of each submission, and narrowed the field to 10 finalists. ...

Rounding out the winners' circle in third place is the Intracranial Cerebrospinal Fluid Pressure Regulator. The entry, submitted by Bob Paddock, was inspired by a personal experience; his wife committed suicide after an excruciating headache that resulted from cerebrospinal fluid leakage.

"The inspiration for this dream device obviously came from a very personal place," said Jamie Hartford, managing editor of MD+DI. "The Intracranial Cerebrospinal Fluid Pressure Regulator is a novel improvement over the standard of care for intracranial hypotension caused by cerebrospinal fluid leaks, a condition that can cause devastating headaches. I like that it uses wireless power transfer, which is really the next step for implantable devices."

Thank you for voting on my design. Hopefully it will get the attention of some medical manufacture...

See 1st and 2nd place winners here: http://www.mddionline.com/article/3-winners-announced-dare-dream-medtech-design-challenge