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Topic: LTC2495 ADC breakout board (Read 2026 times) previous topic - next topic

ktellefsen

I've recently discovered Arduino controllers, and I like them.  I used an Uno, a 256kbit memory chip and some sensors to make a datalogger.  It was fun and it worked!

I collect a lot of electrical data, slowly, but a lot.  I need lots of channels and and at least 16 bit resolution.  Linear makes the LTC2495 16 bit, 16 single ended/8 differential channel I2C MUX ADC chip.  I designed a breakout board for this chip to be controlled by an UNO, and I'd like to have someone else look at my gerber files.  The circuit was copied from the chip's datasheet.

I also designed a temperature humidity sensor and a real time clock breakout, again the circuit was copied from the chips datasheet.

Is this the right place to post this?

CrossRoads

Sure. Please post the schematic and the board.
Are you using Eagle, something else?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

ktellefsen

I use ViewMate Deluxe; I started by designing test coupons with little or no electrical functionality.  Until now, any functional circuits have been built on vector board.  QFN packages can't be used on vector board.  I get pad and paste footprints from the datasheets, just as when I design coupons for dummies (packages with no chip).

Where do I post my circuits and gerber files?

CrossRoads

Reply, and Attach jpgs of the schematic and board design. Not gerbers. 
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

ktellefsen

Here are gif files

CrossRoads

The individual files are hard to make out with the component values overlaid on the traces.
Things I could see:
1. Add more 0.1uF decoupling caps (Vcc to Gnd). 1 on the VCC pin of each device, locate close to the pin.  If a device has multiple VCC pins, use multiple caps. 0.1uFs react fast to supply current for fast switching transistors in a device. 10uF are good for smoothing out incoming DC and  big current surges.
2. Add pin 1 indicator to the board symbols, helps prevent parts being installed backwards.
3. Add cathode indicator to the board diode symbols.
4. Add + (or -) indicator to any polarized caps if used.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

ktellefsen

Thanks for the advice.  I was unaware of point 1; that's why a 0.1µf AND a 10µf capacitor was shown on the datasheet schematic.  2 - 4 are good practice, thanks.

If you like I can post better pictures.

CrossRoads

Its up to you. I don't think I'll have any more to offer tho.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Billhigdon

I used Ultralibrarian to do conversion of the Linear technologies LTC2495 cad package  . bxl file for use in Eagle. I'm not sure how to post the results to the forum.

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