6.3 Simulation of the Device Characteristic with MINIMOS-NT

To generate the data from which the compact model parameters can be extracted several device simulations with different bias conditions were performed.

Figure 6.2: log(I_c) and log(I_B) vs. V_be.

The most important parameters of the static compact model can be extracted from plots of $\log\left(\ensuremath{I_{\mathrm{c}}}\right)$ vs. V_be and $\log\left(\ensuremath{I_{\mathrm{b}}}\right)$ vs. V_be with $\ensuremath{V_{\mathrm{bc}}}= \ensuremath{\mathrm{0~V}}$ as can be seen from Fig. 6.2.

Fig. 6.3 shows a plot of the simulated $\log\left(\ensuremath{I_{\mathrm{c}}}\right)$ and $\log\left(\ensuremath{I_{\mathrm{b}}}\right)$ vs. V_be. The resulting forward current gain $\beta_{\mathrm{f}}^{}$ is shown in Fig. 6.4. The maximum forward current gain for this device is 390 at $\ensuremath{I_{\mathrm{c}}}= \ensuremath{\mathrm{8.39~\mu A}}$. Fig. 6.5 shows a plot of the simulated $\log\left(\ensuremath{I_{\mathrm{e}}}\right)$ and $\log\left(\ensuremath{I_{\mathrm{b}}}\right)$ vs. V_bc. The maximum reverse current gain $\beta_{\mathrm{r}}^{}$ is 123 for $\ensuremath{I_{\mathrm{e}}}= \ensuremath{\mathrm{38~\mu A}}$ (see Fig. 6.6).

Figure 6.3: Simulated log(I_c) and log(I_b) vs. V_be.

Figure 6.4: Forward current gain.

Figure 6.5: Simulated log(I_e) and log(I_b) vs. V_bc.

Figure 6.6: Reverse current gain.

Fig. 6.7 shows the simulated output characteristics for several base-emitter voltages. The quasi-saturation region which is the operating region between the saturation and the nonsaturation region is very large and extends to collector-emitter voltages up to approximately 2 V.

Figure 6.7: Output characteristic for different base-emitter voltages.