DAC5681Z: DAC5681Z output circuit simulation

ashish gopal

Part Number: DAC5681Z
Other Parts Discussed in Thread: DAC5682Z

Hi,

Referring the https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/32555/dac5681z-output-model

I got DAC5681Z output model from above link , and referring DAC5682z EVM user guide pg37, I trying to simulate the output at SMA ( in the diagram shown above it is the 50ohm load VF3 pin) using TINA . Im able to get output voltage of 0.8Vp but I need 1Vp output.

Please suggest me the necessary changes to be done in circuit to achieve the required output.

Best Regards,

Ashish

over 1 year ago

0 jim s over 1 year ago

TI__Guru* 91947 points

Ashish,

What frequency is your output tone? What mode are using for the DAC? Is your gain set to 0xFF (max setting) in register 0x07?

Regards,

Jim

0 ashish gopal over 1 year ago in reply to jim s

Prodigy 130 points

The frequency is 60Mhz and yes gain is set to 0xFF.

Regards

Ashish

0 Chase W over 1 year ago in reply to ashish gopal

TI__Mastermind 18145 points

Ashish,

Can you send me the register writes for the mode you are using? We are trying to get one of these running in our lab and this would help to expedite the process on our end.

Thanks

0 ashish gopal over 1 year ago in reply to Chase W

Prodigy 130 points

Hi Chase

I want to know how to increase the output voltage from 0.8Vp to 1Vp. Any changes to be done in circuit level as i want to use DAC in full gain mode.

Regards

Ashish

+1 Rob Reeder over 1 year ago in reply to ashish gopal

TI__Mastermind 20080 points

Hi Ashish,

What is the exact PN of the transformer you are using. If you use a 1;4 impedance ratio that will gain up the output fullscale voltage.

You can also try moving the 1kohm pullups (R1/2) down in value to up the output voltage.

Regards,

Rob

0 ashish gopal over 1 year ago in reply to Rob Reeder

Prodigy 130 points

Hi Rob

I made pullup(R1,R2) to 500ohm and transformer impedance ratio to 1:4. I got fullscale voltage.It worked.

Thank you ,

Ashish

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DAC5681Z: DAC5681Z output circuit simulation