Dear Sirs,

Please answer:

1. On page 5. of the AD9786 datasheet it is written:

Gain Drift (with Internal Reference) ±4 ppm of FSR/°C

Reference Voltage Drift ±30 ppm/°C

Is it correct?

2. What is the gain drift with EXTERNAL reference?

3. Is it possible to switch off all the modulation, interpolation etc. and use the AD9786 as regular high speed DAC, like AD9726?

Thank you for your help.

Best regards,

Aion

Hi Aion -

1. Yes this is correct.

2. GAIN or FSR = 32 * VREF/R(FSADJ); R(FSADJ) is a resistor from the FSADJ terminal to ground. An external reference will have a specified temperature drift as will the resistor R(FSADJ). You can calculate GAIN temperature drift with external reference using this equation.

3. Yes it is possible to bypass interpolation and modulation and use the AD9786 as a straight DAC.

Set INTERP[1:0] in the FILTER[01] register to 00

Set MODDUAL bit in the MODULATE[03] register to 0

Set MOD[1:0] in MODULATE[03] register to 00

Thanks,

Larry