JAJSOR6 September 2024 LM706A0-Q1
PRODUCTION DATA
A Type-ll compensator using a transconductance error amplifier (EA) is shown in Figure 7-3. The dominant pole of the EA open-loop gain is set by the EA output resistance, ROEA, and effective bandwidth-limiting capacitance, CBW as shown by Equation 23.
The EA high-frequency pole is neglected in the above expression. The compensator transfer function from output voltage to COMP node, including the gain contribution from the (internal or external) feedback resistor network, is calculated in Equation 25.
where
The EA compensation components create a pole close to the origin, a zero, and a high-frequency pole. Typically, RCOMP << RO-EA and CCOMP >> CBW and CHF, so the approximations are valid.Figure 7-3 circles the poles in red and the zero in blue.