Chapter 13, Problem 13.56P

In the bias portion of the CA1340 op−amp in Figure 13.22, the bipolartransistor parameters are $V_{BE}\left(\text{npn}\right)=0.6\text{V}$ and $V_{EB}\left(\text{pnp}\right)=0.6\text{V}$ and the MOSFET parameters are $V_{TP}=-1.2\text{V}$ and $K_p=0.15{\text{mA/V}}^{\text{2}}$ .(a) Determine the currents $I_1=I_2$ . (b) If the bias voltages are $V^{+}=-V^{-}\equiv V_S$ , determine the minimum value of $V_S$ such that the biascurrents are independent of the supply voltage.