I have a circuit that uses an AD9281
If I connect VREF/2 to both inputs I should get code 128 out.
For channel 1 I am getting 128 + 16 and for channel 2 I am getting 128 + 32
VREFB is 1 volt and VREFT is 2.5 volts
I suspect something wrong wit VREFT as…
I am using the ad9281 as the basis for a USB oscilloscope.
The first problem is noise if I go above 10MHz clocking.
If I reduce the clock speed the noise goes down.
The other problem is with 1 volt in I am getting code 166 out when it should be 128.
…Alex,
First, regarding using the internal VRef for assiting in the level shift - in this case the Vref internal to the part is not buffered, and is only designed to drive the Vref inputs for the ADC itself, (see fig 18). If the Vref was buffered, then…
| AD693 |
| AD5410 |
| AD5412 |
| AD5420 |
| AD5422 |
| AD5735 |
| AD5755 |
| AD5755-1 |
| AD5737 |
| AD5757 |
| AD5421 |
| AD421 |
| AD5758 |
| AD7569 |
| AD7669 |
| AD7868 |
| AD7869 |
| AD5593R |
| AD5592R |
| AD5940 |
| AD5941 |
| AD7293 |
| AD7294-2 |
| AD7292 |
| AD5590 |
| AD7294 |
| L… |
