06-03-2014 08:01 PM
Can we connect the output of LM35( attached fig vout) directly to J7 connector VinA or VinB pin of Spartan3E? While testing the output of Lm35 is varying from about 260mv to 285 mv.
06-03-2014 08:37 PM
What is the package of the device? Is the J7 pin a VCCO input?
In that case you need to check the Device datasheet and search for the recommended operating voltage and see if this voltage is in range - However the voltage oscillation is not recommended and the power supply is expected to be stable.
06-03-2014 10:57 PM
It looks like you are refering to VINA & VINB of ADC in SPartan 3E starter kit.
The allowable voltage range of these pins is given in table 10-2 of http://www.xilinx.com/support/documentation/boards_and_kits/ug230.pdf
06-04-2014 06:53 AM
Yes, I am taking about VINA and VINB input toAnalog circuiary in Spartan 3E. Thank you, I went throught ug230 guide. As per the guide the minimum input voltage to preamplifier is 0.4V, is it? My analog voltage varying from 260mv to 285 mv, do I need to amplify my signal before giving to preamplifier,I am right?
06-04-2014 07:09 AM
06-11-2014 07:03 PM
In the spartan3e boards with build in ADC circuit and with gain of-1 and Vin as 1V, then ouput will be 4259 as per equation ; D[13:0] =Gain x((Vin-1.65V)/1.25V )X 8192. I am getting this result, but how can I retrieve back my orginal input voltage (1V)?