J
James Meyer
- Jan 1, 1970
- 0
James Meyer wrote...
The diode has a traditional logarithmic component, which
is both current and temperature sensitive, and a series
resistive component, which follows ohms law. At high
currents the resistive component by far dominates. If
two high-current power diodes are paralleled, the current
sharing will be largely determined by the relative values
of their intrinsic series resistance. While for a given
type of diode these resistance values will likely be the
same, they are not guaranteed to be the same, and may in
fact not be, especially if they have different date codes.
The series-resistance component of diodes I have measured
have varied by up to 50%.
Thanks,
- Win
whill_at_picovolt-dot-com
And what does that 50% in Rs variation together with the diode's other
characteristics translate to in terms of current sharing? If one of the diodes
would otherwise tend to hog current, its temperature and junction potential
would rise and begin to force current into the loafing diode.
A 1N4148 in parallel with a 1N4004 would not share current very well,
but two of either type should share nicely.
Jim