INA208: INA208 offset voltage question VS output accuracy

Red Yen

Part Number: INA208

Hi Support team

As D/S mentioned, the offset voltage is 2mV (typ) which mean the differential voltage would NOT less than 2mV to insure the output accuracy (less than +/3.5% max)

my question is that while differential voltage > 2mV, may we still need to consider this parameter (offset voltage) if we would like to calculate the output accuracy?

in the other hand, is offset voltage influence the output accuracy in normal operation mode?

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Red,

I'm not sure whether I understand you correctly, but the input offset voltage is an important error term because the input offset voltage undesirably adds to the input voltage measured across the shunt.

Kai

0 Ian Williams over 6 years ago in reply to kai klaas69

TI__Mastermind 27715 points

Hi Red,

Input offset voltage is an unwanted input voltage created by mismatch in an amplifier input stage. You can consider it as another voltage source in series with your "real" input signal. This directly contributes to output accuracy, especially at low input signals where your input signal may be similar in amplitude to Vos.

I highly recommend you watch our "Getting Started with Current Sense Amplifiers" video series to review some of the fundamentals, especially these:

Best regards,

Ian Williams
Applications Manager
Current & Magnetic Sensing

0 Red Yen over 6 years ago in reply to Ian Williams

TI__Expert 4360 points

Hi Williams,

thanks for your reply, therefore, the Input offset voltage is NOT included the output accuracy (less than +/3.5% max), which showed in D/S page one
in the other hand, i need to consider input offset voltage if i would like to calculate the max Gain tolerance?

0 Ian Williams over 6 years ago in reply to Red Yen

TI__Mastermind 27715 points

Hi Red,

Input offset voltage IS included in the output accuracy (less than ±3.5% max) spec. Please see my response on your other post below. The ±3.5% includes the effects of input offset voltage and gain error.

https://e2e.ti.com/support/amplifiers/f/14/t/803774

Best regards,

Ian Williams

Amplifiers

Amplifiers forum

INA208: INA208 offset voltage question VS output accuracy