The reverse-saturation currents of a Schottky diode and a pn junction diode are \(I_{S}=5 \times 10^{-8} \mathrm{~A}\) and \(10^{-12} \mathrm{~A}\), respectively.

(a) The diodes are connected in parallel and the parallel combination is driven by a constant current of \(0.5 \mathrm{~mA}\). (i) Determine the current in each diode. (ii) Determine the voltage across each diode.

(b) Repeat part (a) for the diodes connected in series, with a voltage of \(0.90 \mathrm{~V}\) connected across the series combination.