Suppose we have a junction diode operating at a constant temperature of 300 K. With a forward current of 1 mA, the voltage is 600 mV. Furthermore, with a current of 10 mA, the voltage is 700 mV. Find the value of n for this diode.

Community Answer

Honor CodeSolved 1 Answer

See More Answers for FREE

Enhance your learning with StudyX

Receive support from our dedicated community users and experts

See up to 20 answers per week for free

Experience reliable customer service

Get Started

Step 1le know the diode current equationI_{D}=I_{5}\left(e^{\frac{V_{0}}{n V t}-1}\right)since diode is forward blasedone can approximateI_{D}=I_{S} e^{\frac{V_{D}}{D_{T}}} \text { as } e^{V_{D} / n U T}>1Dusing forword bras conditions.When V_{D_{1}}=600 \mathrm{mV} \quad I_{D_{1}}=1 \mathrm{~mA}\begin{array}{l}V_{D_{2}}=700 \mathrm{md} \quad I_{D_{2}}=10 \mathrm{~mA} \\V_{T}=\frac{K T}{q}=\frac{1.3806 \times 10^{-23} \times 300}{1.6 \times 10^{-19}}=25.887 \mathrm{md}\end{array}k - Boltzman's constantq t charge of-electronT \rightarrow Temperalire in KStep 2\begin{array}{l}\frac{I_{D 1}}{I_{D 2}}=\frac{I_{S} e^{\frac{600 m^{V}}{n V T}}}{I_{S} e^{\frac{700 \mathrm{mV}^{V}}{n V T}}} \\ \Rightarrow \frac{\operatorname{ImA}}{\operatorname{lomA}}=e^{\frac{600 m v-700 m v}{n V T}} \\ \Rightarrow 10=e^{\frac{100 m v}{n v T}} \\ \ln (10)=\frac{100 m U}{n v T} \\ n=\frac{100 \mathrm{mv}}{(v i) \ln 10} \\ =\frac{100 \mathrm{mv}}{(25.887 \mathrm{mv})(\ln 10)} \\ n=1.677 \\ \text { ' } n \text { ' value for given diode }=1.677 \\\end{array} ...