LMH6553: Feedback resistor selection

Shinya Sawamoto

Part Number: LMH6553

Hello team,

The feedback resistor is recommended on the datasheet as below.

In case of increasing it to make a gain higher, what are the main concern and risk?
(I can guess the bandwidth will get lower. Could you advise if there are any critical things.)

Thanks in advance.
S.Sawamoto

over 4 years ago

0 Michael Steffes over 4 years ago

Guru 48395 points

Table 1 and 2 on page 21 show fixed Rf vs gain, this does reduce the input R to go to higher gains,

If you want to just increase the feedback R to get higher gains that will work but bandlimit through the gain bandwidth product - with a slight change in phase due to the feedback pole to the input C moving down a bit as well - simulations should show all of that approximately.

0 kai klaas69 over 4 years ago

Guru 140200 points

Hi Shinya,

how much do you want to increase the feedback resistors?

Kai

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LMH6553: Feedback resistor selection