Hi,
I am trying to simulate in LTspice the next circuit using INA828:
Vptp = 4V
Vcommon = 2.5v
Vref = 2.5V
Gain = 1
Vcc = 5V
Vee = 0V
I expect to receive output signal between 0.5-4.5V (2.5V +- 2V )
according to datasheet it's suppose to work:
this is my result:
what am I missing? why the limits of the output are 1.5-3.5V?
Thank you is advance,
Roman
Hey Roman,
Using our Analog Engineers Calculator (link below), I am seeing that with the conditions you have outlined the max differential input is +/-1 V. The max output is 3.5 V and 1.5 V. Operating outside of these conditions will give non-linear results. Please verify that the Vin+ and Vin - max and min values on the real circuit are within the linear range shown below.
https://www.ti.com/tool/ANALOG-ENGINEER-CALC
I have simulated the conditions in Tina Ti (file attached below). Please ensure that your input differential signal is no more than 1 Vpeak.
Best Regards,
Chris Featherstone
Hi Chris,
Thank you for your fast answer!
I can't understand this behavior, it's not according this graph in the data sheet:
Anyway, may be you can help me to find more suitable component.
My input is -2.5 - 2.5V (5Vpkp)
And in my application negative voltage is forbidden
The output must be 0-5V (rail to rail)
Any suggestions?
Thanks!
Hey Roman,
Based on your input voltage range I have simulated the circuit and I also match your bench results for the output voltage behavior. Our calculator and the simulation align with the bench results. I will pass this information to our systems team. Unfortunately the only option for a rail to rail INA would be the INA326.
Best Regards,
Chris Featherstone
