ad8055 as a voltage follower

Question

Hi, 
 I am considering using a high output drive current OP AMP as a voltage follower. I found that AD8055 meets the current requirement but in its datasheet, there's no unity-gain stable mentioned. 
 I wondering if AMP without unity-gain stable could be used as a voltage follower. 
 
 Thanks in advance.

GLADION · Accepted Answer

Hi ANALOGR , 
 
 Good day. Considering the open loop gain response and the phase margin of the op-amp, we can say that the op-amp is stable at a gain of 1 since it has a positive phase margin (this was based on stability criteria). 
 
 Although the close loop gain response shows a little peaking for frequency above 40 MHz which could only affect the linearity of the output, the part is ensured to have gain flatness 0.1 dB to 40 MHz 
 
 Hope this helps. 
 
 Regards, 
 Gilbeys)

maaarmas · Answer

Hi ANALOGR , 
 There are some cases that amplifiers can be used as voltage follower without unity-gain stable, but for AD8055 case, it is unity-gain stable which can be seen in this plot. 
 
 Hope this information helps. 
 Thanks, Mae

Electronic Design Services - PartnerZone

Products Mentioned

ad8055 as a voltage follower