Hi Steven,
Thankyou for your response.
1.
StevenX wrote:
Could you make the issue more clear ? After power up, one CONVST pulse is applied, the BUSY keeps high forever, right?
This problem is solved. No more issue with Busy output.
2.
StevenX wrote:
To be simple, please pull /STDY to VDrive through 3.3kohm resistor and OS[2:0] pins to Ground. Then, power up the board, apply the RESET pulse, wider than 50ns, as specified in datasheet. check the function of CONVST and BUSY. It is better the waveform capture of CONVST and BUSY by scope can be provide.
As you have suggested, I have connected /STDY to VDrive through 3.3kohm resistor and OS[2:0] = 0,(No Over Sampling).
RESET pulse is 5ms(>5ns)
Now the resulting scope waveforms for CONVST, BUSY & FIRSTDATA o/p's :
CONVST = 4.4us for OS=0.
BUSY = 3.6us for OS=0.
BUSY & FIRSTDATA o/p : FIRSTDATA = 3.6us.
Till this it is working fine but for input & output I have problem.
The analog input is given 2Vpp, 500mHz from Function Generator to CHANNEL 1, and all other Channel 2 to Channel 8 are grounded.
18-bit Digital Output is converted from 2's Complement form to voltage using the calculation:
// converting the 2's complemented binary result to corresponding voltage
if(array[i] <= 0x1FFFF)
{
array[i] = (array[i]*2)/13107.2; // for 10v range (numerator*2)
}
else
{
array[i] = 0x3FFFF - array[i];
array[i] = (array[i]*2)/(-13107.2); // for 10v range (numerator*2)
}
Output from all channels is stored in 'array' for 1 conversion: (CCSv4)
And this is not constant for next RUN. Value changes time to time which should not happen actually.
Please help me with this issue..
Thank you.