how to drive a large capacitive load?

Status
Not open for further replies.
K

katrin

Full Member level 1
Joined
Dec 3, 2005
Messages
98
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
2,200
a circuit output is going to drive the next stage circuit which is a large capacitive load of the previous stage(please see the simplified picture below)

In order to drive this large capacitive load, should I consider about increasing the current flowing in the previous circuit or should I increase the size of the transistors Q1 and Q2?

In general, in order to drive a large capacitive load, how can I optimize the circuit?
 

Put a super buffer between the 1st stage(q1/q2) and the loading cap.
 

    K

    katrin

    Points: 2
    Helpful Answer Positive Rating
If you are driving the capacitive load with an inverter which is seen from your schematic, rather than using a single inverter use chain of inverters namely "tapered buffer".
 

    K

    katrin

    Points: 2
    Helpful Answer Positive Rating
U will have to increase the current and correspondingly the size of transistors also, which will increase the input loading of that stage, u may have to add another stage before that to run it.
2 or 3 stage buffers can run a large capacitive load.
Hope this helps.
 

    K

    katrin

    Points: 2
    Helpful Answer Positive Rating
normally, which kind of buffer can be used here, in order to obtain an output signal which is the same as the buffer input?
 

katrin said:
normally, which kind of buffer can be used here, in order to obtain an output signal which is the same as the buffer input?
Click to expand...

You can use a simple OTA with a unity gain feedback. Determine the current based on output capacitance and bandwith requirements of the signal.
 

    K

    katrin

    Points: 2
    Helpful Answer Positive Rating
We can use two stage, differential to single ended buffer with 2nd stage being inverter with active load (with compensation).

Added after 41 seconds:

We can then connect the differential buffer in unity gain buffer configuration.
 

    K

    katrin

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…