INA270A-Q1: the Max Full Range Offset +- 3mV is applied at the fixed Gain = 14 ?

Paul Kim

Intellectual 1430 points

Part Number: INA270A-Q1
Other Parts Discussed in Thread: INA270, INA271

Hi Team

may I get your quick response ?

INA270A-Q1 has Max Full Range Offset = +- 3mV and Gain = 14[V/V].

customer wants to know the max offset at the fixed Gain = 14[V/V].

the Max +- 3mV offset is applied at Gain = 14[V/V] ?

or I has to calculate Max +- 42mV offset by (3mV x 14) ?

I believe INA270(Gain 14) and INA271(Gain 20) have the fixed gain respectively,

so that the Max full range offset is applied at the fixed gain,

but I need BU's confirm.

over 7 years ago

0 Peter Iliya over 7 years ago

TI__Mastermind 32395 points

Hey Paul,

You are right. The +-3mV is the specification for the amplifier’s input offset (Vos). This is why we label the specification “Vos, RTI”. RTI stands for “referred to input”. RTI Vos error is modeled as positive voltage source on non-inverting terminal. Thus, in order to determine the Output offset, you multiply RTI Vos by the gain.

Analyzing error (including Vos) is discussed in our training video series here: training.ti.com/getting-started-current-sense-amplifiers

Sincerely,
Peter Iliya
Current Sensing Applications

Amplifiers

Amplifiers forum

INA270A-Q1: the Max Full Range Offset +- 3mV is applied at the fixed Gain = 14 ?