SLUAAL2 Application note

Figure 1-24 Type 2 Compensator Without Fast Lane

Equation 47.

G_{c} (s) = |\frac{V_{f b} (s)}{V_{o} (s)}| = \frac{R_{f b} C T R}{R_{L E D}} (\frac{1}{(C_{v} + C_{f}) \cdot R_{u p}} \frac{1 + R_{v} C_{v} s}{(1 + \frac{s R_{v} C_{v} C_{f}}{C_{v} + C_{f}}) s})

Equation 44.

\begin{array}{l} Assuming C_{f} < < C_{v}, G_{c} (s) further simplifies to \\ G_{c} (s) = \frac{R_{f b} C T R}{R_{L E D}} (\frac{1}{C_{v} \cdot R_{u p}} \frac{1 + R_{v} C_{v} s}{(1 + s R_{v} C_{f}) s}) \end{array}

Equation 45.

This can be written as G_{c} (s) = G_{o} (\frac{\frac{ω_{L}}{s} + 1}{1 + \frac{s}{ω_{p 1}}})

Equation 46.

where G_{o} = \frac{R_{f b} C T R}{R_{L E D}} (\frac{R_{v}}{R_{u p}}) ω_{L} = \frac{1}{R_{v} \cdot C_{v}} ω_{p 1} = \frac{1}{R_{v} \cdot C_{f}}

Here $ω_{L}$ is low frequency inverted zero and $ω_{p 1}$ is a high frequency pole.