Question about gain settings

Hi DanielM2 ,

Good day. The output scaling gain settings  the ADA4255 versatile when interfacing with a wide selection of sensors and ADC. This allows the configuration to extend the gain into multiple gain selections. As an example, if your system needs a gain of 2.25, you can set the input gain of ADA4255 to 2 and put the Output scaling gain to 1.25 to accommodate your configuration 

Regards,
Gilbeys

Hi Gilbeys,  Thanks for the information but my question was specifically why those output scaling factors are offered.  My assumption is that there is some special application where the customer gets an advantage by having this extra degree of freedom.  Or perhaps there is some trick that customers use to calibrate their system by switching to these special gain settings?  The 1.375X gain setting is also offered on the PGA280 by TI so there must be some reason or customer need for these settings.  If the extra gain settings were simply to offer more gain flexibility then why not offer the extra gain steps as part of the regular gain settings? Or why not offer a 1.5X gain setting so that the customer could have twice the resolution in gain settings?

-Daniel

Hi Daniel,

ADA4254's usual target applications are those where they need to amplify very small signal and maintain its signal integrity (lowest noise or highest accuracy as much as possible). ADA4254 fits this requirement as it is in the PGIA architecture where accuracy and precision is prioritized. Aside from what Gilbeys has mentioned, the output scaling is also the means for the user to amplify the signal as high as possible. ADA4254 is one of our highest gain set PGIA with the G of 176. As for why this and that is the certain gain level, its on the level of IC design limitations. We try to offer flexibility as much as possible.

Let me know if this answers your question.

Thanks!

Kristine