Hi,

I am designing an Improved Howland Current Source of 500uA using AD8041. The bandwidth needed is DC to 2MHz. The load variation expected is 10 Ohms to 10 kiloOhms.The circuit is as shown below:



The circuit when implemented gives a bandwidth of 1MHz.How can this be improved?

 

Is that real bandwidth or simulated bandwidth?
If real, then you may have too much stray capacitance in the circuit.
How was it constructed?

 

Is that real bandwidth or simulated bandwidth?
If real, then you may have too much stray capacitance in the circuit.
How was it constructed?

Its the real bandwidth.I used a NI ELVIS board to implement the circuit.The output probe used was Tektronix TPP0200 voltage prode which has a capacitance less than 12pF. There could be bread board capacitance as well.

The frequency response obtained is as shown:


Will I get a better response if I implement the circuit using a general purpose PCB?