Dear all,

I would like to clear few things with the circuit i have.

http://www.8052.com/users/Sur...design.pdf

I am not clear with the DAC(AD7548) connected to the OPA 547 through a LF412.
This setup is used for driving a coil for Reed Switch closure.

I found that the DAC being the current o/p one, delivers .2777A when the input data are all logic 'high'.
So, the voltage at the output of LM412(U4A)pin 1 = Vo = .2777 * 33 = 9.1641 V.
If what i described above is correct then,
here, iam not sure of what is the current that would be sourced by LM412U4A pin 1.
Also, in the OPA547 part iam not sure of what is the o/p voltage(at coil+, coil-) i would get with such a setup and having the current limit being set.

I would like to have some discussions on it.

Thanking you,
Suresh.