Hello,
I am trying to make an antilog detector that is as accurate as possible at certain points, (Vshape, Vantilog). A couple of these points that should be upheld are:
@ Vshape = 0.95V, Vantilog ~ 2.0V
@ Vshape = 0.779V, Vantilog ~ 0.632V
By simulating with ideal diodes and ADA4807, these values are closely met (assuming the ideality factor is 1 and the thermal voltage is 26mV). When I try using the diodes 1N4148, the slope of the function has been reduced. I know the ideality factor has increased (1.752 in ltspice), which I've taken into consideration and adjusted the resistances that decides the exponential value accordingly. The function is still quite slack compared to "ideal", and I was wondering if any of you know of any diodes better suited for the application, or a solution that could make the 1N4148 diodes get a more ideal functionality.
S.
I am trying to make an antilog detector that is as accurate as possible at certain points, (Vshape, Vantilog). A couple of these points that should be upheld are:
@ Vshape = 0.95V, Vantilog ~ 2.0V
@ Vshape = 0.779V, Vantilog ~ 0.632V
By simulating with ideal diodes and ADA4807, these values are closely met (assuming the ideality factor is 1 and the thermal voltage is 26mV). When I try using the diodes 1N4148, the slope of the function has been reduced. I know the ideality factor has increased (1.752 in ltspice), which I've taken into consideration and adjusted the resistances that decides the exponential value accordingly. The function is still quite slack compared to "ideal", and I was wondering if any of you know of any diodes better suited for the application, or a solution that could make the 1N4148 diodes get a more ideal functionality.
S.