Adjust offset of Sine wave

[Bilal_Ahm]

Hi seniors,

I am using DAC of Microcontroller (SAM4S 32-bit) to generate Sine wave, my problem is that the output sine wave have offset about 500mV that i do not want and there may be another way to adjust it. but can i adjust the offset by using op amp? sine wave is 100mV peak to peak and with adjusted offset it should come below from 500mV to 60mV.

Thanks in Advance.



Regards
Bilal Ahmad

 

[barry]

Many ways to do this, but first, why does your 100mV P-P sine wave HAVE 500mV offset? That sounds like there's something wrong with your software, or DAC. Unless you are INTENTIONALLY generating your sinewave this way.

You can use an inverting op-amp with a gain of 1 and a 250mV reference on the opamp positive input. You can use a capacitor. etc.,

 

[Bilal_Ahm]

Many ways to do this, but first, why does your 100mV P-P sine wave HAVE 500mV offset? That sounds like there's something wrong with your software, or DAC. Unless you are INTENTIONALLY generating your sinewave this way.

You can use an inverting op-amp with a gain of 1 and a 250mV reference on the opamp positive input. You can use a capacitor. etc.,

thanks for replying.

i am using one example from atmelstudio to generate sine wave.

uint32_t dac_val = 0;
dacc_write_conversion_data(DACC_BASE, dac_val);

this method convert data for dac output. by putting dac_val = 0; it generate constant voltages around 500mV offset. this shows that dac have limitations to generate less offset voltages than 500mv.

if you can help with register setting that would make my life easier or i have to ask you again for some analogue circuit for that task. I am using sam4s chip from atmel.