ADA4857 as charge amplifier

We were using AD8620 Op Amp in our previous application but now want to use the ADA4857 op amp as integrator / charge amplifier. I have compared the following parameters of both the op amps

Sl. No. Parameters AD8620 ADA4857
1 Supply voltage +/-5V +/-5V
2 Noise (In nV/Sqrt(Hz)) 6 4.4
3 Gain-Bandwidth product (In MHz) 25 110
4 Power supply current / amplifier
(In mA)
3.5 5.5
5 Output Current
(In mA)
+/-30 50
6 Rail to Rail Out No No
7 Amplifier per package 2 2
8 Temperature Grade Ind Ind
9 Temperature (deg C) –40°C to +125°C –40°C to +125°C
10 Package SOIC LFCSP
11 Price ($) 15.35 6.13
12 Height (In mm) 1.75 1
13 Length (In mm) 6.2 4
14 Breadth (In mm) 5 3.75

Should I go ahead with the ADA4857 in our application as charge amplifier?

Do I have to compare any other parameters?

What should be the selection criteria as a charge amplifier/integrator?


  • 0
    •  Analog Employees 
    on Dec 6, 2012 8:48 PM

    The question to ask is why did you choose the AD8620 initially?

    Is it the precision aspect? (offest voltage, input current,...)

    Is it the cap load driver?

    Is it speed?



    Based on that, you can see if these functions match up and you can make your decision.


  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:43 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin