# Errata edition 1.2¶

1. Equation 10.6 should be:

$\lim_{H\rightarrow\infty}\left(\frac{E_o}{E_i}\right)=\frac{1}{k}$
2. Section 11.4.6 should be:

At low frequencies, zeros may cause the loop gain to drop below its midband value. In such cases the servo function obtains a high-pass character with a high-pass cut-off at $$\omega_{\ell}$$. This cut-off frequency can be found in a similar way as the low-pass cut-off frequency $$\omega_{h}.$$ We now only account for the $$p$$ zeros and the $$q$$ poles with frequencies smaller than $$\omega_{\ell}$$ and use the asymptotic approximation according to (11.50) with $$p>q$$. In this way we obtain:

$\omega_{\ell}\approx\sqrt[p-q]{\left\vert \frac{b_{\ell}}{a_{k}}\frac{{\displaystyle\prod\limits_{i=k+1}^{p}}% p_{i}}{{\displaystyle\prod\limits_{j=\ell+1}^{q}}z_{j}}\right\vert }.$
3. Equation 12.5 should be:

$\omega_{h}=\left\vert a_{n}\right\vert ^{-\frac{1}{n}}$
4. Equation 12.9 should be:

$\omega_{\ell}=\left\vert b_{k}\right\vert ^{-\frac{1}{k}}$
5. Page 418: The text below equation (12.38) should be:

From this, we see that a third-order system can be given an MFM characteristic with one negative real phantom zero if

6. Equation 12.62 should be:

$\omega_{h}=\sqrt[3]{\left\vert \frac{1}{a_{3}}\right\vert }$
7. Page 428: The SLiCAP scripts that begins at line 20, should begin with line 19:

result = pzLoopgain.results

8. Exercise 12.2: Change the value of the DC loop gain to $$-10^4$$.

9. Figure 18.27 should be:

10. Equation 18.90 should be:

$\begin{split}\mathcal{R}=\mathcal{I}^{T}\mathbf{G}^{-1}\mathcal{I}=\left( \begin{array} [c]{ccc}% 0 & 1 & 0\\ 0 & 0 & 0\\ 1 & 0 & 0\\ 0 & 0 & 1 \end{array} \right) ^{T}\left( \begin{array} [c]{cccc}% \frac{1}{R_{1}}+\frac{1}{R_{2}} & -\frac{1}{R_{1}} & 0 & 0\\ -\frac{1}{R_{1}} & \frac{1}{R_{1}} & 0 & 1\\ 0 & 0 & 0 & -1\\ 0 & 1 & -1 & 0 \end{array} \right) ^{-1}\left( \begin{array} [c]{ccc}% 0 & 1 & 0\\ 0 & 0 & 0\\ 1 & 0 & 0\\ 0 & 0 & 1 \end{array} \right)\end{split}$
11. Equation 18.91 should be:

$\begin{split}\mathcal{R}=\left( \begin{array} [c]{ccc}% R_{1}+R_{2} & R_{2} & -1\\ R_{2} & R_{2} & 0\\ -1 & 0 & 0 \end{array} \right) . \label{eq-Rmatrix}\end{split}$
12. Equation 18.92 should be:

$\begin{split}\mathbf{T=}\mathcal{RC}\mathbf{=}\left( \begin{array} [c]{ccc}% R_{1}+R_{2} & R_{2} & -1\\ R_{2} & R_{2} & 0\\ -1 & 0 & 0 \end{array} \right) \left( \begin{array} [c]{ccc}% C_{1} & 0 & 0\\ 0 & C_{2} & 0\\ 0 & 0 & -L_{1}% \end{array} \right)\end{split}$