Very low range on LM3914?

Thread Starter

tracecom

Joined Apr 16, 2010
3,944
Is it possible to set the total range on an LM3914 to .05V, with a low of .970V and a high of 1.020V? If it's not possible using the internal reference of 1.25V, would it be possible using two external references, one for the low end of .970V and the other for the high at 1.020V?

Thanks.
 

bertus

Joined Apr 5, 2008
22,270
Hello,

When you look at the internal diagram of the LM3914, you will see a string of resistors between the pins 4 and 6.
Pin 6 determines the max value and 4 the min value.



So a pot (ca.46K needed) from pin 7 (Vref) to pin 6 and a pot (ca. 194K needed) from pin 4 to ground might give you the range.
The total resistance between pin 6 and 4 is about 10 K.

Bertus
 

Attachments

Last edited:
Top