VR-sensor board based on LM1815

Hardware inside and outside of the ECU
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puff
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VR-sensor board based on LM1815

Post by puff »

Hey there! I've decided to share my draft designs of this board with the english part of the forum.
I've seen plenty of various LM1815 schemes for megasquirt, but they are somehow different from what is suggested in the datasheet.
http://www.ti.com/lit/ds/symlink/lm1815.pdf
I've left several jumpers for the board to be flexible enough and accommodate various modes of operation.
I'm planning to power it from 3.3V. Will it be enough? (Do you think I need any dedicated circuitry to protect the inputs of the MCU?)

Anyway, here is my schematics:
LM1815-v1.png
LM1815-v1.png (34.72 KiB) Viewed 5567 times
And here's what I've got for the layout:
lm1815-layou-v1.png
lm1815-layou-v1.png (47.97 KiB) Viewed 5567 times
Few comments:
JP1 - is the sensor output.
JP2 - is for Power Supply and the output to Discovery board.
JP3 allows you to set the mode (adaptive, with arming threshold fixed at 500mV, or with threshold set to 0V)
JP4 & JP5 will define what we get on JP6 (pin 10 - see the table in the datasheet) - not sure if I need it at all.

Board size is 1.7"x1.15". I'll try to etch the board and try it the next week.

There are some difficulties reading the datasheet. What's the difference between pin 10 and pin 12. What voltage level do I expected at those pins with Power supply of 3.3V and 5V? I am planing to use it with 36-1 trigger wheel, revving it up to 6000rpm (3,6kHz?). Seems viable? What's your opinion?
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