DAC query

Hi LTC2664HUH12PBF 

If you source a 66uA load at AO, that's going to cause a voltage drop across your series resistor equal to 301*66u =~19mV. Is there a reason why you need the series resistor at the output of the DAC? 

Best regards,

Ian

kindly reply

kindly reply soon...it is very important and high priority for us

Hi, 

I understand that this is for filtering, and if the load at the RC (AO_x) is high impedance then there should be no drop as you observe in your bench test. But if the load presents some current draw, it will cause voltage drop due to the R in your RC filter

LTC2664HUH12PBF said:

Is it ok to change the DAC output series resistor to 0R ? Will this change to 0R affect the DAC IC ? 

Are you referring to the R32 in your diagram? or the R17? if R17, then the voltage drop would disappear but you won't have your RC filter anymore. 

Best regards,

Ian

Hi, 

I understand that this is for filtering, and if the load at the RC (AO_x) is high impedance then there should be no drop as you observe in your bench test. But if the load presents some current draw, it will cause voltage drop due to the R in your RC filter

LTC2664HUH12PBF said:

Is it ok to change the DAC output series resistor to 0R ? Will this change to 0R affect the DAC IC ? 

Are you referring to the R32 in your diagram? or the R17? if R17, then the voltage drop would disappear but you won't have your RC filter anymore. 

Best regards,

Ian

The LTC2664HUH12PBF DAC's output load capacitance is 1000pF. According to the end application a max. of 10000pF load is expected. So whether any additional circuit is required to be implemented for avoiding oscillations and keep the VOUT stable for 10000pF capacitive load?  

The capacitance load spec is based on maintaining the noise performance of the DAC stated in the specs table. Going beyond 1000pF, we can't guarantee the stability of the DAC. In my opinion, the safest way is install an additional buffer amplifier at the output that is stable at higher than 10000pF. 

Kindly provide the LTSPICE simulation of this DAC circuit to VOUT