Cypress Perform

Home > Design Support > Cypress Developer CommunityTM > Cypress Forums > PSoC® 5 > Transimpedance Amplifier Cutoff Frequency

Bookmark and Share
Cypress Developer CommunityTM
Forums | Videos | Blogs | Training | Rewards Program | Community Components



Transimpedance Amplifier Cutoff Frequency
Moderator:
ANCY

Post Reply
Follow this topic



Transimpedance Amplifier Cutoff Frequency

fdszh posted on 11 Aug 2011 12:50 PM PST
Member
8 Forum Posts

Hi,

I was curious as to how the -3 dB Frequency was calculated for the transimpedance amplifier. The Data sheet says that this is calculated based on

f -3dB = 1/ (2*pi* Rfb* Cfb)

Which is not actually the case for the autocalculated value in the TIA configuration menu.

for example, with:

Rfb = 20k

Cfb = 4.6 pF,

the cutoff frequency should be about 1 729 945.03 Hz ? but the autocalculated value is 866 kHz...

perhaps someone can shed some light on this?

Thanks!




Re: Transimpedance Amplifier Cutoff Frequency

David Ron posted on 12 Aug 2011 10:22 PM PST
Top Contributor
24 Forum Posts

From what I observe, the calculation of bandwidth of TIA is dependent not only on the feedback resistor and feedback capacitor, but also on the power setting selected.

 

The bandwidth is definitely inversely proportional to the product of resistor and capacitor. But if the power mode is set to "High Power", then the Bandwidth is higher. But if the power setting is set to "Minimum Power", then the Bandwidth is miniumum.






ALL CONTENT AND MATERIALS ON THIS SITE ARE PROVIDED "AS IS". CYPRESS SEMICONDUCTOR AND ITS RESPECTIVE SUPPLIERS MAKE NO REPRESENTATIONS ABOUT THE SUITABILITY OF THESE MATERIALS FOR ANY PURPOSE AND DISCLAIM ALL WARRANTIES AND CONDITIONS WITH REGARD TO THESE MATERIALS, INCLUDING BUT NOT LIMITED TO, ALL IMPLIED WARRANTIES AND CONDITIONS OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT OF ANY THIRD PARTY INTELLECTUAL PROPERTY RIGHT. NO LICENSE, EITHER EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, IS GRANTED BY CYPRESS SEMICONDUCTOR. USE OF THE INFORMATION ON THIS SITE MAY REQUIRE A LICENSE FROM A THIRD PARTY, OR A LICENSE FROM CYPRESS SEMICONDUCTOR.

Content on this site may contain or be subject to specific guidelines or limitations on use. All postings and use of the content on this site are subject to the Terms and Conditions of the site; third parties using this content agree to abide by any limitations or guidelines and to comply with the Terms and Conditions of this site. Cypress Semiconductor and its suppliers reserve the right to make corrections, deletions, modifications, enhancements, improvements and other changes to the content and materials, its products, programs and services at any time or to move or discontinue any content, products, programs, or services without notice.

Spec No: None; Sunset Owner: KXP; Secondary Owner: VWA; Sunset Date: 01/01/20