OPA2376-Q1: Vos range of TA = –40°C to +125°C

Hi Chris，

Thank you for your detailed reply.

But from the customer's side, they will use MAX Value for calculation:

Vos = 5 uV + 2 uV/C * 100 C = 205 uV

This value is too high for customers. When should we use the MAX value for calculation?

BR，

Link

Hey Link,

The max drift specification is used to provide guidance over process variation and lot to lot variation. See histogram below. Theoretically some devices can be between 1-2 uV/degC. You calculated it correctly. We have drift trim devices such as the OPA192 that have a max drift specification of 1 uV/deg C from -40 C to 125 C with a typical offset at room temperature of 5 uV.

The OPA2376 and OPA192 are e-trim devices. If the customer needs even lower drift they may consider a chopper device. 

For the OPA2376 the offset drift histogram is shown below. 

Best Regards, 

Chris Featherstone

Hey Link, 

What supply voltage, input common voltage range and output range is the customer needing? What other key parameters are they considering for their design? Any further details would be appreciated for us to provide appropriate suggestions. 

Best Regards, 

Chris Featherstone

Adding to Chris' reply, since the standard deviation (one-sigma) of the OPA2376 drift is 0.32uV/C (typical),  you may self-guarantee a lower maximum offset drift by accepting certain failure rate in accordance with Normal Gaussian distribution probability of failure - see below.

Thus, 

1. if you can accept that 1 in 370 units (3-sigma) will NOT meet the spec, you should use the maximum drift limit of 3*0.32uV/C = 0.96uV/C

2. if you can accept that 1 in 15,787 units (4-sigma) will NOT meet the spec, you should use the maximum drift limit of 4*0.32uV/C = 1.28uV/C, etc.

If this is still not acceptable, you should instead use one of our zero-drift parts:

1. an automotive Grade 1 OPA388-Q1 with maximum offset drift 0.05uV/C or

2. a non-automotive OPA387 with maximum drift of just 0.012uV/C.