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xbee powered with LM3671 3.3V Buck Converter
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xbee powered with LM3671 3.3V Buck Converter

by robinmcc54 on Mon Mar 18, 2019 1:24 pm

I'm building a monitoring system with Xbees using 2 of their analog pins to monitor vacuum levels and temperatures in a sugarbush. The Xbees seem ideal because their coordinated sleep mode would radically reduce the power usage and they should be able to function for months on 3 alkaline batteries. However, when I tried to power the Xbee 900 HP Pro S3B with the LM3671 Buck Converter, the voltage dropped from 3.3 to 2.5 as soon as I put a load on it. The datasheet says that they can draw over 200 MA on transmit but the Buck Converter is rated for 600 MA. I also measured the current and at 2.5 VDC is was only 10 MA (but I'm assuming the Xbee shutdown with low voltage.

Other possibly relevant information:

- I am only connecting the VCC and GND into the Xbee as it's programmed to read the A1 and A2 lines under coordinated sleep (and this is working with other power supplies such as the Xbee Explorer and the Cypress Board.
- The condition was noted with EN floating and with it powered by the 3 AA batteries through a 100 Kohm resistor.

Any thoughts?

Yours,
Robin

robinmcc54
 
Posts: 2
Joined: Tue Mar 27, 2018 8:29 pm

Re: xbee powered with LM3671 3.3V Buck Converter

by robinmcc54 on Wed Mar 20, 2019 7:04 pm

It looks like the Buck Converter I was using was bad. I replaced it with a different one and my Xbee is talking to the host nicely! All I had to do was ask the question and the answer appeared :-).

robinmcc54
 
Posts: 2
Joined: Tue Mar 27, 2018 8:29 pm

Please be positive and constructive with your questions and comments.